The Chemistry of Food & Taste | Dr. Harold McGee

Welcome to the Hubberman Lab podcast, where we discuss science and science-based tools for everyday life. I'm Andrew Huberman and I'm a professor of neurobiology and opthalmology at Stanford School of Medicine. My guest today is Dr. Harold McGee. Dr. Harold McGee is a professor at Stanford University and world-renowned author on the topic of science and the chemistry of food and cooking. He has spent more than four decades researching and writing about this topic. His work is unique because it at once teaches us about why foods taste the way they do, as well as how to make essentially any food or drink taste better. I, like presumably most of you, absolutely love to eat. And for me, that's an understatement. I love food and eating. Today, Harold teaches us about everything from how certain types of cookware, the bowls, the pans you use, even the utensils you use can change the taste of those foods, as well as simple things like adding a pinch of salt to anything bitter. tasting, including coffee. Yes, coffee changes its chemistry and flavor for the better. And he explains why. We discuss the preparation of meat and this thing that we call savoriness or the umami taste and how it's brought about by heating proteins in very specific ways and how you can bring out more of those flavors and how to get more of the healthy compounds such as polyphenols found in chocolate and cacao. And we cover the much debated issue of whether more expensive wines are truly better than less expensive ones in terms of their taste or whether it's all a function of marketing. So if you're a seasoned cook or perhaps you only know how to make a few basic dishes or if your version of cooking is basically a protein shake and some oatmeal, this discussion with Harold McGee will let you understand the essential chemistry of food and cooking and how to prepare food that is far more enjoyable. As I said before, I love to eat and this discussion taught me how to make the foods I love so much. meat, cheese, vegetables, fruit, starches, etc., all taste far better. And since eating is a big part of life, not just a way to support our health, I'm certain that everyone will glean useful knowledge and practical tools from Dr. McGee. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is however part of my desire and effort to bring zerocost to consumer information about science and science related tools to the general public. In keeping with that theme, today's episode does include sponsors. And now for my discussion with Dr. Harold McGee. Dr. Harold McGee, welcome. Thank you, Dr. Huberman. I, like most people, love to eat. I also love food. I love the look of it. I love the smell of it. I love the anticipation of eating. And you've had a truly unique career. We'll talk a little bit more about your background later, but you've had such a unique career focusing on the chemistry of food, food interactions, and I must say, even just knowing a little bit about your work, you've changed the way that I think about even like the sorts of metals that I might use to prepare my food because it turns out these things are all impacting one another in not just small ways, but really profound ways that impact our experience of food and and taste. So, just to kick things off, is there any one wild food interaction chemistry fact that you just particularly find interesting? When I started writing my book about uh the chemistry of cooking, um I didn't know that much about cooking or about chemistry. I was kind of learning on the fly, which was part of the fun. And uh I read when I was writing about eggs that if you're going to make a a foam of egg whites to make a meringue or a sule. So you put the egg whites in a bowl and you whisk them until they uh essentially form a solid from that liquid. Um a solid consisting of uh air bubbles trapped in uh in the liquid and that makes it act like a solid. amazing kind of transformation. Um, and uh, when I was looking at uh, what cooks had said about this process, they said you should use a copper bowl to do that whipping. And so I looked in the chemistry of eggs literature, of which there was uh, a fair amount actually, for some kind of explanation as to why that might be the case. And um, couldn't find one. And so I decided, well, it's probably an old cook's tale, somebody who had a a copper bowl and used that and thought that was better. And so I didn't think anything more about it until I was preparing my book for publication, looking for cheap illustrations because I couldn't afford good ones. And I found an old engraving of a an 18th century French kitchen. And there was a boy acting as though he was whipping something in a bowl. And the bowl kind of looked like our modern um copper bowls with a little ring to hang the bowl on the uh on the wall. And there was a key that came along with the illustrations. And the key actually said uh whipping eggs in a copper bowl to make pastries. So, I thought if the French have been doing it for hundreds of years, maybe there's something to this. Maybe I should uh actually test it, which was a really important lesson for me. Test everything. Uh I I gulped and bought a copper bowl because they're expensive. And um and did a side by side and the difference was tremendous. Different color, different texture, different consistency in the mouth, totally different. um experience. And so it was that um that uh realization that a um a cook's what what I thought might be a an old cook's tale could actually have a a kernel of scientific chemical truth to it. That to me was a a mindblowing and and career-changing experience because from then on I didn't take anything for granted. I always had to give it a try. I love it. I recently started drinking water out of a copper um reusable bottle. Uhhuh. Mostly because I needed a water bottle and there was one for sale where I happened to be and it was copper and I rather like the taste. There are all sorts of theories about copper being better for us health-wise, etc. I haven't explored those to see if they're actually true or if it's um nonsense, but um I I do like the look of it. Is copper used um for the preparation of any other foods specifically in order to extract the best flavor from those foods or or liquids? Uh copper is actually used in jam making, jelly and jam making. And the reason for that is uh that if you use any other uh material, you end up um messing with actually almost everything in there because the temperatures are pretty high. They're above the boiling point. Um but in particular the sugars and if you break sucrose down to glucose and fructose then you know the the behavior of the material changes a lot not necessarily for the better. And it turns out that copper actually inhibits the breakdown of glucose into glucose and fructose. And so again for uh generations uh cooks, French cooks in particular uh have used copper bowls to make uh their preserves. Wow. Copper is used for a variety of things. Um it sounds like and people have arrived to this through what sounds like kind of an unconscious genius combined with um uh experimentation. When scientists got interested in cooking, they sometimes made um claims and uh and suggested changes that in fact were terrible ideas. The traditional way of doing things was actually much better. they had come up with a partial understanding of what was going on and on the basis of that partial understanding decided that they needed to correct cooks who of course weren't as smart as they were uh uh and get them to change. And so you can see in the middle of the 19th century some cookbooks published in in England and the US having a subtitle you know the back in the day long subtitles were uh were enjoyed and so this the subtitle would be in which the theories of Dr. Leebig have been as much as possible applied in in the recipes and Liebig was he was a genius um biochemist but on cooking he kind of took his genius for granted and was wrong. The the cooks knew better. Yeah. I love um this notion of unconscious genius that a field of people who are experimenting without any formal rigorous coursework in a given area like chemistry can can arrive at at truths without understanding the the mechanistic basis of those truths. Yeah. You know actually I think a lot of what we face nowadays in the the sphere of health and nutrition is about that conflict. you know, there there are papers identifying mechanisms, but then they don't play out in clinical trials, which is the, you know, and then there are people in the real world who are doing things for which there's really no peer-reviewed research, but you get the sense that maybe they're on to something, you know. So, it's a very interesting intersection of um uh expertise and uh and real world results. Yes. Or sometimes collision of of the two. I'd like to take a quick break and acknowledge our sponsor, Eight Sleep. Eightle makes smart mattress covers with cooling, heating, and sleep tracking capacity. 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As I mentioned before, I love to eat. Um, and we could talk about any of the different major food groups. um as an exploration of the chemistry of food. But I think one of the more interesting ones is the combination of heat and food, right? Um and very often people will ask me, you know, like is microwaving safe? And things like that. And I've uh didn't ask me anything recently where I said yes indeed microwaves are safe. You probably don't want to stand right in front of it in case the the mesh protector isn't isn't as effective as it might be. But yeah, it's heating things up from the inside. But we have all these different ways to heat up food and we have ways to heat food and then cool food as a way to enhance the flavor of food. When it comes to um the use of heat in food, what do we know about the history of the the use of I imagine it was fire first, but um this is a vast you know topic but um what are some of the interesting ways in which heat interacts with food at the chemical level to allow us to enjoy that food more? Yeah. So, um, in the anthropological literature, of course, the focus is on, um, uh, increasing caloric intake and being able to, uh, consume materials that we wouldn't otherwise be able to consume as efficiently. So, um, that's that's the sort of practical side, but my feeling is that the use of fire wouldn't have caught on if it didn't make foods delicious, more delicious than they'd been in the first place uh, at the same time. And and in fact probably um people early on uh learned to associate particular sensory experiences with the nutritional value of what it was they were eating and maybe even the safety because uh you know if you kill a mammoth you've got a lot of leftovers and uh what do you do with them so that they don't spoil and and make you sick later on. So um the the terrific thing about the application of heat to foods in general is that they heat kind of takes the materials uh of which the food is made and rearranges them um and in many cases breaks molecules down into smaller molecules that um that we can actually detect with our senses of taste. taste and smell. So, uh, proteins, carbohydrates, fats, that's what we think of as constituting food, but they're all, um, macroolelecules. They're they're way too big for us to experience directly. And uh so one of the things about cooking that's that's most important is that cooking will take those macroolelecules and break down uh enough of them to produce small molecules that we can detect with our senses of taste and smell and um and enjoy simply for that reason. uh you know we have my my feeling is that we have our senses um for them to be stimulated and um so in many cases even if the um if the stimulation is borderline pleasurable or maybe even slightly unpleasurable, we still enjoy the fact that we're being stimulated, that something is going on with our senses of taste and smell. And cooking uh does that in spades. It takes these these um molecules with no taste or smell and turns them into bouquets of various kinds depending on the original material. Yeah. When I think about a piece of steak um and if I were to take a bite of it raw um it would taste very different uh cold versus room temperature. And then raw steak, which to me is not appetizing. Um, cooked even just a bit, especially if it were seared on the outside. Um, now becomes pretty darn good. Cook it a little bit more, like medium rare, with a really nice sear on the outside. I think they call it Pittsburgh char. Anyone that likes the outside of the steak really nice uh nice and charred and the inside rare, it's Pittsburgh char if the chef knows what they're doing. um is uh absolutely delicious. Um so what's happening there? I mean that you know you said that heat changes the molecular structure but what what about those changes allow us to taste it um more not just differently because as you said like like raw steak is pretty bland. I mean it's I mean most of us probably think of that as kind of gross but um it's also kind of bland compared to when um when it's cooked. What's happening? what's being uh released into the into the steak. Yeah. So what what happens is that the materials of the tissue and in the case of meat it's mostly uh protein and fat um those um macroolelecules large molecules that are too big for our senses to uh to register get broken apart. And um that's because heat is energy. energy uh agitates things. Um it agitates molecules at the surface of the food enough to break them apart into much much smaller pieces. And it's those pieces that were um that we're experiencing when we take a bite. Uh the pieces are not only much smaller, but they're uh also reactive so that they can react with each other. they can react with oxygen in the air surrounding the food. And so we end up with um you know if you if you did a an analysis of the aroma coming off of um some steak tartar and coming off of a a Pittsburgh char. um you're going to have very very little uh noticeable uh even with uh instrumentation, but off of the the stake a tremendous amount of um volatile molecules, which are the ones that our our noses detect. And then also molecules that are small enough to stimulate our taste receptors. So we have a handful and they uh we we think of them as responding to sweet, sour, salt, bitter, umami um tastes. Um we we encounter those tastes in all kinds of things in everyday life. But when you uh cook a a piece of meat to a high temperature and do a good amount of damage to that outer uh uh molecular surface, you generate molecules that can stimulate those receptors even though they themselves are not sugars or salts or or whatever. What I like to think of is just the alchemy of uh of heat. you know, you you take this material, you add energy, and you transform it in ways that are delightful to us. So, if I understand correctly, even though um the molecules in meat, uh typically wouldn't stimulate the sweet receptor, when you cook steak, it starts to stimulate the sweet receptors because of the change in those molecules. you you've you've reduced their size and you've changed their their configuration depending on which recipe you use. Yes. And and you're also generating uh where once you might have had um you know uh well these days our enumeration of molecules has gotten so good that who knows exactly how many are in that raw piece of meat. uh whatever that number is, it's multiplied manyfold by the application of heat simply because it's taking those materials, breaking them apart, getting them to react with each other. Um and uh the result is just an explosion of sensory um uh information that simply wasn't there before. We have to talk about umami. I mean, not just because the name is fun to say, but um this uh receptor that seems to uh bind molecules um that give us the sensation at least in part of savoriness. Uh, I mean, to me, few things are as delicious as the um braise that comes off of meat in a cast iron pan, that I would literally scrape that stuff up onto the spatula and eat it if uh no one's looking. Um, and anyone that thinks that that sounds gross, I mean, it is absolutely delicious. I mean, it is like the the the pinnacle of like why we eat protein. That's why it feels so darn delicious to me. Um, and the the intensity of flavor per unit of of whatever that stuff is um is so high. But then here's the thing. If you were to wait two hours and come back and pick up one of those little black, you know, um, crumbs of braise and put in your mouth, it will kind of like punch you in the mouth and it tastes like kind of awful, like you were licking the um, the grill of a barbecue from two days before. Not good. So, what's going on with with braze and with umami? And we can talk about a lot of nonmeat um ways to stimulate umami, but such a an interesting aspect to food and taste. Yeah. Yeah, it is. And something that when I started writing about cooking in the 70s, no one believed it existed except for the Japanese scientists who were living in the country where it was discovered in the first place. That's right. They were the first to molecularly clone the umami receptor as far as I know. And they were also the first to claim that there was a uh sensation, taste sensation that was not sweet, sour, salt or bitter. Uh which is why they were disbelieved in the west for for decades and decades. And when I as I say when I started writing that was the standard view. Japanese have this weird idea of something a basic taste um that's just simply not correct. Um, and I I went to a couple of meetings in Boston and remembered this being debated among uh uh chemists. First, I'll just say that uh I know exactly what you mean about the that flavor uh of something that you apparently feel guilty about enjoying because you you said you would uh uh scrape it up when no one was looking. When I was growing up, there were we family of four children. Um, my mother would occasionally make a uh an ovenbaked chicken uh cut up into pieces and um the drippings would drip down to the pan and brown. And after the meal, my siblings and I would line up for a spoonful of the scrapings. Delicious. I can I I can smell it and taste it just a bit. Yeah. Anyone that's cringing at that, you have not tasted proper braise from meat. It's uh assuming you consume animal uh proteins, it is um absolutely delicious. Yeah. Yeah. Yeah. I can I can it it just takes me back. It's pristian to go back to that. U so u to make a long story short, the Japanese were shown to be correct uh by western standards. They always knew they were correct, but by western standards they were proved to be correct when a receptor for uh glutamate was discovered uh in the 2000s. Yeah, early 2000s. Uh so finally, Western scientists were on board. Um meanwhile, cooks uh had been on board for a long time uh because they're always looking for ways to make their food more delicious. and they'd heard about this. Some went to Japan, they came back and um so uh umami is um a sensation that's a little bit difficult to uh to describe compared to sweet, sour, salt, and bitter. Um savory, I think, is the word you use. And that's the sort of the the usual nomenclature. Um, when you try to characterize it further, it's it's a a feeling of fullness and length. So, the the flavor, there's just a lot of it there and it sticks with you for for a while. That's what we mean by length. Yeah. Got it. I feel like also it um it doesn't occur just in my mouth, you know, and I'm not um like very nuanced about food. food. I mean, I love food, but um I'm not somebody who can really I don't consider myself a food connoisseur. I just know what I like and what I don't like. But I feel like that the taste of something with a lot of umami flavor actually spreads throughout the body. It's like a a whole head experience, maybe even down to the chest. It's not restricted to like a location in on the tongue or something like that. Later we'll talk about this myth about restricted receptors on the tongue. Um yeah, one has to wonder if if um because the umami um receptor stimulation is so closely tied to savoriness and protein and because protein was presumably scarce in evolutionary history, whether or not there's some reward pathways that are like, oh, this is this is good to because people had to work really hard under dangerous conditions often to get umami stimulation. Yes. Yes. Yeah. That's right. And um uh I I would also say that from at least my reading of the the literature, we only know a tiny tiny bit about what's going on when we smell things and taste things. So we know the the initial step there's a receptor on our tongue that responds to glutamate which which is associated with this sensation. What happens after that? Who knows? Um and and there's also the fact that glutamate is an important u molecule in the body for signaling. So who knows what kind of you know cross talk there might be between the the receptor on the tongue and the rest of the body. And people have also in the last what 10 years or so discovered uh taste receptors for all the tastes in our GI tract. Yeah, that is so interesting. I and so important too because um Oh, maybe that's the sensation that um things are uh that the umami taste is is much deeper. Yeah. Is that that they're in the esophagus and presumably maybe even into the stomach. Yeah. Yeah. Um wild. I heard um that tigers have something like 10,000 fold more umami receptors than humans, but they have no sweet receptors. I don't know if that's true. Usually when you hear something like that, it's likely to be not completely true, but who knows? We look it up and and someone will tell us in the comments. Um, which upon hearing made me immediately want to try being a tiger for one day. Like, I can't even imagine how good meat tastes to to carnivores that have that density of umami receptors. But it raises another question too which is assuming that's true. Would the absence of the sweet receptor perhaps make meat taste completely different? You know in other words is there cross talk between these receptors so that when you eat something that's like this spoonful of of braise drippings off the the the roasted chicken. Um presumably there's a some stimulation of the sweet receptors. If you only had umami receptors, maybe it wouldn't taste good at all. Is the chemistry of food occurring in the mouth, not just um in the food itself? Wonderful questions. I don't know where to begin exactly, except to say that when you um brown a piece of meat or um just cook it to a high temperature so that the outside of the meat changes color. uh that that color change is indic an indication of some a group of reactions called the Mayard reactions after the guy who actually didn't quite address this but he got he got his name associated with it anyway. Um the Mayard reactions are essentially reactions between fragments of proteins and fragments of carbohydrates and fats. And uh the reaction pathways are really complicated. They still haven't been worked out completely, but they generate a bunch of different classes of products. And among those products are sugars. So you don't start out necessarily with sugars, but if you've got proteins and fats, you can make sugars simply with the alchemy of uh applying heat. So that's part of what's going on. And I would say that um yeah, tigers are missing out because there's an interesting dimension of flavor to to meat uh that that has been cooked. There's the chemistry of cooking and then there's the chemistry of enjoying, of tasting, uh, consuming. And it turns out, uh, that that's complicated in its own right because first of all, we're presenting our sensory apparatus with um, the most complex materials that they're going to encounter. Nature does not uh, generate this kind of complexity. uh we're we're doing it for ourselves and that's part I think of the of the great pleasure that we take from it. Um but it also turns out that in the mouth changes can take place and this is act was actually first uh noticed by uh experts in wine because they found that when they um put a raw grape in their mouth to taste you know what what what's the characteristics of the of this particular grape and how does that carry over into the wine? What they noticed was that initially there's just the taste of the grape, but then as they sit there, other flavors begin to uh come and because they were experts in wine tasting, they were able to uh figure out which ones they were and they they were some of them molecules that you find in the finished wine and it's just in your mouth. You just chewed it. So it turns out that there are in um all kinds of foods um molecules that are uh called conjugates. You know, they're um uh kind of business end of the molecule and then usually attached to a sugar of some kind. And um when we put something in our mouth and we have enzymes in our mouth, uh those enzymes can go to work on things like conjugates and free up um the sugar from the uh rest of the molecule and the rest of the molecule can be aromatic. And uh it's known now that the Mayard reactions generate not only sugars but conjugates. And so, uh, there's there's just a lot going on. And it's it's a, uh, I think one of the best arguments for, uh, enjoying your food slowly because you never know what's going to kind of show up in your mouth, uh, after, you know, 20 or 30 seconds in. Slow down, enjoy every bite, and and notice what's happening. uh because it's uh it's often a really dynamic uh experience, we're going to have a hard time convincing many people to slow down their rate of eating. However, if you promise them a richer experience of the food and not just that they're trying to eat less or something, which is the usual reason that people hear they should chew their food, maybe improve digestion as well. Um they might be incentivized to do it. I should point out of all the senses um seems taste and its relationship to food we have um more control over that experience. Like let me state this differently. If I were to do a podcast on you know that simply by looking around the world differently you could start to actually get new visual perceptual abilities. That'd be pretty exciting. But I'm sorry but that's not true. It doesn't work. I mean, you could enhance your, you know, some discrimination of certain things if you were trained to look for them, but you're not going to change your visual perceptual abilities. But with taste, it sounds like we we have the ability. So, when you say slow down, do you mean um slow down the chewing, take pauses after um bites? Um, all of the above. Yeah, all of the above. Because even after you swallow, there are residues in your mouth and at the back of your mouth. And that's what the wine experts noticed was the change in those residues. So, it's not that they chewed on a grape and then kept it in their mouth for a minute. Uh, it was just what was left over. So, the leftovers can be as delicious as the main course. All right, I'm going to start taking pauses between at least food types. Um, I've sometimes had the experience of eating something particularly delicious. Um, for instance, uh, meat. um or fruit or vegetables. I love all the the I'm an omnivore, so I love all these things, but I'm so satisfied with what I just ate that I don't want something sweet right away because of the collision that occurs between foods. Am I alone in not liking dessert, but liking dessert foods on their own at a separate time? Am I or am I just like on a desert island of experience here? No, I'm actually uh completely the same. Um I u I would prefer to have another half glass of wine than dessert. Uh just simply to prolong the experience of the the the main part of the meal. U and dessert, sweet things I enjoy, but not after um a big meal of of other things, savory things. Um, my wife uh who's Japanese says she has uh a separate mouth and a separate stomach for desserts and she can go right into it after um after the the main course, but yeah, I I prefer not to. I feel like many people eat dinner just to get to dessert. Let's actually talk about food order in the meal. Um, many years ago, uh, I had a girlfriend who was from the south of France, from the Perry Gord. So, she grew up in what is arguably one of the food capitals of the of the planet. You know, people think French food Paris, but actually people in the south of France are so serious about food that her family would spend most of the day and the night and the meal talking about the next meal or a previous meal. Um, they would search for mushrooms with binoculars. If they spotted one in the neighbor's yard, they were like perplexed as to how to negotiate for that mushroom. You couldn't actually go get steal the mushroom. That would be like a a cardinal sin. I mean they are so serious about food every aspect of it as you know. And we used to get into these intense arguments about the order in which one is supposed to eat food. And you know in her mind it was soup first because it actually prepares the gut and then always salad last. this whole notion of eating uh salad at the beginning of the meal was like heresy to uh I mean to everything that she had had known and and conceptualized about food. So, I have to believe that whether one likes French food or not, that they they're on to something that when it comes to digestion, when it comes to being able to really taste the the full array of flavors in a food that we probably should be doing soup first, then an appetizer, then an entree, and then salad last. and if we're not consuming an entire, you know, meal of that sort that salad shouldn't be eaten at the beginning of a meal. Are they right? I'm pretty sure that she was right. She was right about most things. Very good question. And I guess my answer would depend on the audience. So, and I say that because of course, if you go to a a banquet in China, everything is served simultaneously. Really? They just slide it all out in front of you. And do people eat everything in kind of mishmash? Or there may be um phases, but you're presented with many many different dishes at each phase. Oh, I would be so overwhelmed. And it is overwhelming. I And you know, it's partly uh well, I I don't want to uh generalize. Maybe it has to do with um perhaps uh emphasizing the the uh abundance and and generosity of the meal rather than focusing on the pleasure that you can get from each stage in it. Maybe it's um maybe the French are more focused on the the sensory experience. But there are many many different ways to um to sequence dishes in a meal. And um I I think it does the the the French way of doing it uh does make a lot of sense. Uh my family and I lived in uh the countryside near Tulus for a year and um ate around with the neighbors and so on and and my daughter my and son went to school where they were given a full hour for lunch and it was a coursed lunch with all those different components. Uh so it it does make sense I think because um having the soup uh come early helps um among other things partly fill your stomach so that when you then go to the main course um you don't have to eat as much in order to be satisfied. And then the salad, you you know the salad is coming and it kind of refreshes you because the main course is usually um on the heavy and rich side. Almost always. Yeah. Yeah. Goose breast with for gr was not uncommon in her household. Yes. And they were a middle-ass home, I should mention. So it wasn't that people there were eating goose breast with for gr because they were among the like elite. It was that was the uh ham and cheese sandwich of the of the town. Yeah, those are those are the local products and uh the the geese were probably being raised down the road. So yeah. Um, so I think u the the salad kind of closes out the the main part of the meal and refreshes you a little bit and then if you're going to have dessert, you're ready for it rather than being overwhelmed by yet another rich um uh another rich course. So I think it does make a lot of sense for the for that uh structure of a meal where you have those different courses. Yeah, this notion of um cleansing the pallet is kind of an interesting one. Um it's been a long time since I've been to a meal where they served a pallet cleanser in between dishes. I mean that that's something that I think in the 80s and 90s became a little bit popular in the United States and my family wasn't serving or attending those sorts of meals, but I' I've been to a few. It's kind of an interesting idea. But um molecularly, chemically speaking, is is that a real thing that you're going to wash out the flavor of what you just ate so you can prepare for the next uh next item on the menu, or is it more um for for show? I I think it's both. Um I I I do think that you know if you're uh and again depending on the the details but pallet cleansers are usually cold and um you know not uh not too strong in any direction. Um a little bit tart often. Um so something cold and tart to break up a meal where you've gone from one kind of rich course and you're you're about to have another rich course because it's a fancy restaurant. Um, I think that probably does make sense. Mhm. Yeah. My next question is a bit more of a human physiology question, but I think we're all familiar with the kind of um taste intensity drift. I can't think of a better phrase where you know if you are used to drinking your coffee black and you start putting a little bit of cream in it, maybe a little bit of cream and a little bit of sugar, going back to black coffee feels like a step in the really bitter direction. Um and then if you start adding more sugar or eating sweeter foods, it seems like we reset our threshold for what we consider too sweet. And there are all sorts of health implications, negative health implications around this. But um is that a real thing? Are are we actually changing our threshold for what we consider bitter or sweet? I asked this because recently I've developed a um I won't call it an addiction, but um a love for um cacao beans. And the first time I bit into one of those, I thought like those are bitter. And now it's one of my favorite parts of my morning where I'm like pop five or six of those in my mouth and munch on them and they they taste bitter but they taste so good and they're kind of barky. They have kind of like a bark taste to them and I I swear I can taste the polyphenols although that's all all cognitive right. So what I just described is not uncommon uh for me. It What is this whole thing about thresholds for for bitterness and sweet and do they interact? Yeah. Yeah. So taste is uh hugely malleable as far as we can tell. And um I think this is best documented in the literature trying to find ways to reduce the sodium content of of um packaged goods. So um manufacturers have been saying um long after um biomedical people were saying we should cut back on our sodium intake. Uh we would be happy to do that in our products but our consumers don't like our products without the level of salt that we have in them. So people at the Monell Chemical Senses Center in Philadelphia did some uh pretty systematic studies of this and what they found was that you can over time adjust uh thresholds and preferences for the basic tastes. They were focusing on salt because that was the the issue at hand. Uh but there's no reason to think that that's not not the case for everything. That if you uh become used to a particular level of stimulation, then that becomes your your new normal and anything below or above that is going to stand out for being uh not quite enough or too much. So I think the the we're perfectly capable of training ourselves to uh adjust our preferences. Um uh it does take time. So the Monell study I think lasted maybe a couple of months. Takes time but but it's certainly doable. I'd like to take a quick break and acknowledge our sponsor AG1. 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Matina makes loose leaf and ready to drink yerba mate. I've often discussed yerba mate's benefits such as regulating blood sugar, its high antioxidant content, and the ways that it can improve digestion. It also may have possible neuroprotective effects. It's for those reasons and the fact that Yerba Mate provides, in my opinion, the most even and steady rise in energy and focus with no crash. The Yerba Mate has long been my preferred source of caffeine. I also drink Yerba Mate because I love the taste. And while there are a lot of different Yerba Mate drinks out there, my absolute favorite is Matina. I'm excited to share that Matina has recently launched a series of new flavors of their cold brew all zero sugar yerba mate. There's a raspberry flavor, there's a mango flavor, there's a mint flavor, there's a lemon flavor and a peach flavor. And they are absolutely incredible. If I had to pick one that's my absolute favorite, it would probably be the mango or the raspberry. But frankly, I cannot pick just one. And I end up having basically one of each every single day. Again, all of these flavors are made with the highest quality ingredients, all organic, and again, all zero sugar. If you'd like to try Matina, you can go to drinkmatina.com/huberman. Again, that's drinkmatina.com/huberman. I stopped eating quote unquote junk food a long time ago, and I've totally lost interest. In parallel to that, I enjoy strawberries and vegetables and meat and fish and eggs and rice and oatmeal so much more with each successive year. Mhm. And I think it's in part because of this reshaping of of what one considers flavorful, but I also feel like my experience of food is getting richer and richer as opposed to worse and worse. So, it's kind of interesting and and kind of counterintuitive. Do we have any um evidence that if you eat foods closer to their um let's just say in their unadulterated form that uh you get more out of the taste experience than if you are combining lots and lots of flavors which is essentially what um processed foods are. Yeah. Um I I can't point to uh you know chapter and verse in the in the literature on this, but I think it just makes uh common sense that if you're uh going to start with strawberries and then add a bunch of other things um you know, vanilla extract and uh sugars and uh who knows what else in order to um Um, essentially as processed foods try to do, just kind of wow your mouth with an overwhelming sensation that you then want to repeat. Um, rather than slowing down and enjoying the nuances. Um, the natural world gives us these amazing ingredients like strawberries and blueberries and oats and and so on. And then to to take those amazing ingredients which you can kind of savor for, you know, a minute at a time uh and and really enjoy. uh to to take those ingredients and make them um ingredients rather than things in themselves and combine them with lots of other things. Uh for the purpose of stimulation rather than the purpose of appreciating and enjoying those individual components, then you're kind of um giving up, I would say, most of the pleasure of eating. you're just fueling yourself with stuff that um is going to give you an immediate hit of flavor and then be gone. And uh what what was in that food is opaque. You know, it it may have been strawberries once upon a time, but uh it's now been masked by all these other things. And meanwhile, the one of the miracles of living on this planet is strawberries. And the the the just vast range of materials that plants have gone to the trouble of preparing for the sake of pleasing us. And so to to hand that um that uh responsibility or or that activity over to manufacturers who are just looking to make things as cheaply and quickly as possible I think is a a mistake. Do you drink coffee? I do. How do you prepare your coffee? I uh grind the beans and fresh every time. Yeah. Is that important to the taste? It can be. I mean, it depends on where you get your your beans from, but um uh and and how long they last. Uh but uh I I think so. Yeah. So, you'll mill the beans each time. Yeah. And then uh you use a a drip filter, a machine, a French press. A drip filter. Yeah. Yeah. We have this colleague of ours at Stanford uh the Adler who built the the Aerop press which I've used for years long before they were involved with the podcast. I I remember seeing him um uh throwing the arrow frisbee. So he's an inventor, right? And um I I think that the air press is an interesting idea because it sort of combines French press and filter drip, right? It's kind of a um but yeah, there are actually really interesting data that um coffee has some perhaps uh it seems um some powerful uh healthpromoting effects, but it depends on how you brew it. So, how how are you brewing it? Not that I'm going to get you to change the way you do anything with food or drink. So, I I go back and forth between a a metal filter and a and a paper filter. Mhm. And um yeah, I I lived uh near the park where uh Alan Adler would uh fly his Arabes. And so I visited with him and chatted about the the Aerop press. And I I like the idea a lot. And it seems to me you can control the flavor with it much more than you can with a with a drip system simply because when it drips, it drips. But you can hold it into the hold it in the arrow the arrow press as long as you want. The temperature of water is so critical with coffee. Do you take it to a boil or no? I know people might think, gosh, they're really getting down into the weeds, but the flavor of coffee is completely different. If you take the water to a boil versus just get it um near boil or uh cut off the heat a moment after it starts to boil. Completely different beverage. Yeah. In my opinion. Yeah. Yeah. And I actually prefer uh coffee uh drip coffee uh with water right off the boil. So I've tried uh all the different stages and that's that's just my preference. It's the the important thing though is to know that the temperature does make a difference and um the pleasure you get from it is going to vary depending on the temperature you of the water that you use. So, it's worth knowing that and then playing around and seeing what you like best. So, that's the experience side of it chemically and um what's happening. I mean, when you when you brew coffee, what are some of the interesting uh coffee chemistry factoids? I'm obsessed with this stuff as you can tell. Yes. Well, uh so first of all, there's the the grind size makes a huge difference. Um because what you're essentially doing is extracting uh extractable materials from the solids. Um and uh a typical cup of coffee, you're extracting maybe 20% of the weight of the the original weight of the coffee. So it's not that much uh except that it's all the good stuff. And in fact, the the longer you extract, the more you extract, the larger the molecules you're able to remove. And those larger molecules are the ones that tend to be tanic and aringent and really bitter. Yes. The longer you um let the beans or the the ground beans um be exposed to the hot water, the more large molecules you pull off. The large molecules are the ones that give it that kind of punch you back in the mouth. Yeah. Um feeling the tanic. Yeah. Interesting. And bitter. In fact, it's kind of a fun experiment. If you if you love coffee and you're interested in this kind of thing, what you can do is um uh make a a um uh set up a filter with coffee in it and line up four or five different cups and then pour the water in and then every 30 seconds or so move it from cup to cup. And you can see what comes out early and middle and late. And what comes out late are these larger molecules. And late is kind of um um synonymous or or you can think of using hotter water as the temperature equivalent of brewing later and later that you're getting more stuff out. The word that comes to mind is stale coffee that's been on the coffee pot a long time. Is that that seems to be the flavor you're describing when you you uh pull these large molecules out. Is that right? Well, actually, I would say that uh so so yeah, the the old fortunately not so common anymore, the old coffee earn that you would have at conferences and things like that or the one where you pump the Yeah. Yeah. Some people will know what we're talking about. Yeah. The coffee has been in there for a couple hours probably. uh that to me is uh stale coffee and that's that's um changes in in the smaller aromat aromatic molecules as well as the the larger ones. But uh I think the the take-home lesson is that these little details make a difference. And um if you're a stickler for coffee just the way you want it, then doing some of these experiments to see, you know, what's what's on either side of the coffee that you brew uh usually is worth knowing about. Yeah. I think everyone could afford to slow down their experience of consuming food for a variety of reasons. Some of which uh you mentioning uh ta like just straight up better taste and taste experience. Um, and also with beverages, um, I I consume a an ungodly amount of caffeine each day. I'm very caffeine tolerant. I actually can't drink coffee in the morning. Um, but in the afternoon, I absolutely love it. It tastes it tastes aversive to me early in the day. I don't know why drink yerba mate early in the day and throughout the morning. And then in the afternoon I like a cup of coffee and the same cup of coffee tastes absolutely delightful in the afternoon. I don't know what it is. Yeah, that's that's mysterious to me too. Can't claim pregnancy either. So um you know because uh that people who are pregnant report feeling kind of nauseous to certain tastes at one time a day versus another. Um is there anything else we can do with our coffee and tea? you know, so I the the tanic flavor or the the experience of a tea being too tanic is awful. Tastes metallic. Um but when tea's done right, it's very smooth. What is this tanic smooth thing in the context of tea? Is it the same thing? Large molecules, small molecules. Yeah, it's basically the same thing. It it also depends on, you know, what's left in the tea leaf. So some tees are u just by definition going to be more tanic than others because they have been treated differently in order to make the dried tea. Um I have u three or four tea bushes in my backyard and so I make tea every year. Um whenever the new growth comes out that's what you make tea with is What kind of tea do you make? Uh that's the fun thing about having the bushes. I make all kinds and I play around with them and you know see what happens if I just you know pluck a leaf and brew that or pluck a leaf let it wither in the sun and then brew that or do the various processing techniques. They give you ulong, which is kind of medium um manipulated, and then black tea is very heavily manipulated. But it's a whole spectrum and it's a lot of fun to play with. And you're just putting these directly into hot water. You put it in a like a metal tea strainer. For most of them, what you have to do first is dry them. Mhm. Uh but then when I make tea, um yeah, it's just leaves into a pot and then uh pouring the tea out. I I make small pots so so that I can try lots of different things. How do you dry them? Uh that's another variable. So you can let them air dry. You can just out on the counter. Yeah. Yeah. It takes takes um I live in San Francisco, so it's not very warm, so it takes a while for them to dry on the counter. But you can also I put them in the uh toaster oven. I'll dry them. A lot of Chinese green teas even are dried in a in a walk. So I will do that. Heat them up in the walk. Yeah. Yeah. Uh toaster oven. Um yeah. As somebody who's obsessed with yerba mate since I was a kid, I've been drinking yerba mate. I love love love it as you as people know. Um fascinated by this. So um how much space does one of these plants take up? Well uh so it it totally depends. that uh I bought mine originally as um quarter meter tall um not exactly seedling because they are bushes and so they they get ligignified pretty quickly. They're they're more what's ligignified? Sorry. Um like like a tree. So yeah, solid a solid base. Oh, like ligan. Okay. Yeah. Yeah. Lignified. Yeah. Um, so, uh, it and one of the cool things about being alive these days is that, um, it used to be really hard to get your hands on these plants, but now it's very easy. You go go online, you can find many, many different sources at many different, uh, maturities. But the the thing about making tea from tea plants is that what you're doing is plucking off the new growth. That's what you make tea from. It's not the older leaves, it's the the very newest ones which are the most metabolically active and have the most interesting stuff in them. Interesting for us when we play with them. So, uh you actually don't want to make tea from small plants. You want to let them grow bigger. And you can control the the size from from then on up. Um they're they're often grown in the shade uh for flavor purposes and so growing them in the shade is actually fine. You don't have to have a sunny spot on your uh window sill, although it'll grow faster in the sun, but but shade grown tea is uh is actually preferred. Um and then they're they're a species of chameleia, so they're you know not that demanding. They they need acidic soil, but apart from that, very easy to grow. I've had mine now for almost 20 years. And uh um making tea from them is actually a great way to keep them in check, you know, otherwise they would take over the yard. Amazing. Um then what's is it called? Tiography. Do you do that too? The reading of tea leaves. I'm just joking. Um, tea leaf reading is a probably never going to make it onto this podcast and I'll probably upset some people um by saying that. I'm not convinced that reading tea leaves is is uh indicative of much. Yeah. Yeah. Okay. I'm glad we're in agreement about that. as long as we're uh you know exploring whether um longstanding lore within kitchens is uh reflective of some real chemistry uh as was the case with umami or the the French with eating uh salads last. There's this idea that you shouldn't have tea at the end of a meal. Is that true? Um, or is it is it like uh that it somehow hardens the food in your stomach or is this just complete like uh is this complete nonsense? Sounds to me in the direction of complete nonsense. Great. Cuz I like tea at the end of a meal. I like chamomile tea after a meal. Well, and herbal teas especially because I mean I could I could make a a just so story about the the phenolic compounds in tea cross-linking things in your stomach or something like that because polyphenols do that but I can't imagine that it makes a difference. So polyphenols cross-link proteins. Yeah. Yeah. For those who aren't familiar cross-linking proteins is a way of changing their configuration and making generally makes them more rigid. When we in laboratories when we use fixitive like formaldahhide or paraphirmaldahhide um you're taking a tissue usually a slice of brain tissue which is very floppy and you need to be less floppy so you can work with it and so you put it into parapirmaldihide or formaldahhide or glutalahhide all these things create what are called shift bases do I have that right yeah okay my remembering my chemistry and they cross-link the proteins so that then you can pick that thing up like a well it's a very thin slab I would not want to do that to the food in my gut Right. But nowadays we hear that polyphenols are like the greatest thing. So what's the deal with polyphenols? Um should we consume them separately from proteins? Yeah. No, I I don't think so because the the thing about polyphenols, the reason that they do this cross-linking uh is the fact that they're reactive. And what that means is you you put them in with almost anything else and they're going to get bound and then you're going to swallow them uh and they're going to, you know, make it down to your lower GI tract and then there they may be, you know, freed up because the whatever they're bound to gets to be digested and so on. But there it's not a bad thing necessarily. In fact, it's it's probably a good thing. So, but the the thing about polyphenols early on in the process, if you think about what would happen if, for example, you take milk and add some uh wine to it and let it sit, it'll curdle. And that's because the polyphenols are cross-linking the u the milk proteins. And so, that's basically the kind of thing that's happening inside us. years ago, there was a semi-popular diet. This was in the early 90s, um, that argued that you shouldn't combine carbohydrates and proteins, that you should actually eat them separately. And I've also heard it said that you want to eat fruit before a meal or away from a meal, but not after a meal, because it can give you digestive issues. I'm sure people differ tremendously in terms of what they can consume. I I'm actually one of these people. I if I have a stomach ache, it means something is seriously wrong. Yeah. I mean, I can eat everything except metal shavings and my stomach doesn't hurt. I don't get headaches or stomach aches. I get other things, but I don't get those. Some people are very sensitive to food combinations. I get stomach aches really easily. So, um, regardless of one's sensitivity to different foods, are there certain foods that it would make sense to keep them separate if you have digestive issues? you know, um, you know, bloating or, um, just like gurgling stomach, this kind of thing or worse. Yeah. So, um, my understanding is, well, first of all, I know for a fact that, uh, we have cycled through every possible permutation of these theories over the course of the last 150 years um, with no one of them actually being touted now as the the answer. So to me what that says is there is no the answer for this kind of question and that it really does depend on individual physiology and what what people can tolerate um for their own particular reasons. I don't think there are any um principles by which you can choose to uh combine or not combine foods um that would make a difference to your health. Also, it's um you know, we're eating so many different things so many times a day that uh it I think would be really hard to kind of tease out any particular relationships like this. And even if they do exist, they probably exist only for subpopuls and not for the world at large. So translated, what I'm hearing is you have to figure out what works for you. doesn't sound like you believe in one particular um nutrition plan or diet according to any particular science, but it does sound like you leaning toward the idea that certain diets, for lack of a better word, will work better for different people. Yeah, I guess I would I would certainly say that it would depend on the the individual. And I'm I'm not sure that I would buy in necessarily to the idea of an optimal diet in the first place because um unless optimal included uh tremendously varied, which is kind of, you know, uh uh in a way the opposite of optimal. you know, it's it's it making sure to try uh a lot of different things all the time rather than huing to one particular um approach. So, um yeah, I I think we just don't know enough to to say anything definitive. We talk about the uh ever problematic onions and garlic. There's a lot of chemistry around onions and garlic. uh most notably the crying caused by uh onions. What is the basis of the crying caused by onions and how do we mitigate it? So uh plants in that family, the aliium family uh so onions and garlic are close relatives. Um they the way that they defend themselves from animals that might want to eat them and they're not fruits. are actually roots or um rootlike structures that are meant to give rise to the next generation. So to the plant they're very important. They're defended with these sulfur molecules that in the intact route are uh inactive. But then the moment the tissues are disrupted, enzymes get to work and generate from those uh precursors kind of um uh chemical warfare cylinders. The the cylinders are opened and uh we end up with these um uh molecules that can fly through the air. They're volatile. We don't have to actually touch the the onion. they they come to us these molecules uh and they're meant to do exactly what they do which is make us uh miserable. So the fact that they're uh volatile means that you can u protect yourself by doing a couple of different things. You can wear goggles which pres prevents volatile molecules from getting to your eyes. you can do the uh the cutting uh interspersed with just a rinse in water because that'll the the um molecules are being generated at the surface that you're generating by doing the cutting. So if occasionally you just rinse those surfaces then um the volatiles go away and they don't bother you as much. You can also get um um non-pungent varieties of onions which which exist. U Maui onions are the the best known of those and they just don't make those sulfur molecules so that they don't uh they don't uh irritate us. I'm reminded that our colleague at Stanford um Dr. Sean Mackey who runs the pain division when he was on this podcast he said that despite many years of traditional uh training in medicine and thinking that a lot of people's reported uh gut issues were perhaps psychosmatic and all this stuff he that he himself had the experience of um getting a lot of gut pain at one point in his life just and not knowing what the origin was and it seemed like it was after certain meals and not others and he did all the necessary self-experimentation to pinpoint that it was onions that were causing this very what sound like pretty severe um gastric issues and pain. Um and it was the histamines caused by ingesting onions, right? These little packets of molecules that cause inflammation. And so, uh, that in part converted into this idea that, you know, when people talk about their their negative experiences with certain foods that, um, they're not making this stuff up, that it's very likely that they have some sort of food sensitivity. And I think now the the landscape of quote unquote traditional medicine is starting to become more open to this. But um in hearing what you just described like these warfare molecules coming out of onions um stimulating a negative re this designed to create an aversive reaction in animals that would eat them and here we are eating these things and then the idea that it would be bad for certain people at first seemed like shocking to the standard uh medical community. But now one of the you know leading experts in the in the world of pain medicine is like hey listen histamines from onions are a problem for people with gut issues sometimes not always. So I think um there's an interesting kind of intersection of of food chemistry individual experience and where medicine and is headed. It's it's not crazy. These are chemicals coming out of food. Makes sense. Yeah. Exactly. And maybe the the most prominent example of an aversive chemical being generated in foods that we love is capsaasin in peppers. So hot peppers, the the uh the ones that are spicy are spicy because they contain a particular molecule that is designed to be aversive to animals so that animals won't um chew up those fruits before the seeds can be dispersed. And interestingly the the animals that the plant depends on for dispersal are birds and birds don't uh respond to capsaasin. They don't have the really Yeah. Yeah. So this is a a molecule that that's designed specifically for mammals like us to get us to leave those those uh fruits alone. And um some people can handle tremendously noxious, shall we say, uh levels of capsaasin and other people are very very sensitive and and um can't can't handle hardly any. So yeah, it's all part of this um this larger picture of the world giving us these materials to feed ourselves and our working out our u negotiations with those materials so that we can enjoy them and be nourished by them. I want to explore spiciness a bit more in a moment. Are there any data that there are genetic differences uh among people in terms of the density of um I think the capsain receptor is a substance P receptor or something like that or sweet receptors or umami receptors that would perhaps not predict but partially explain why some people are really averse to spice other people pursue spice um and why some foods perhaps just like don't taste good to certain people or even give them a gut issues or uh this sort of thing. So the the best studied uh aspect of this is taste rather than smell. Smell is difficult because there are so many different receptors and thousands and thousands of uh smells but taste is a relatively uh confined subject and there are um what are called super tasters and this has to do eventually I'm sure with genetics but the way this category of people was first defined was by simply counting taste buds on the tongue. So they they had a particular area in which they could look and they stained the the taste buds and then simply counted them enumerated them on uh thousands of different people. And what they found was as you might expect uh there are some people with very very few in a given area and others where they're so crowded together you can barely count them. Wow. So high pixel density, low pixel density. Some people have the iPhone 1. Some people have the iPhone whatever we're on now of uh 16 or something or 13 uh density. Wow. Yeah. Yeah. So clearly that's going to affect the way you experience whatever you put in your mouth. And um uh the the investigators gave the name super taster to the people who had the highest density of um of receptors. It it's unfortunate because, you know, the the term does have um connotations that that are that really don't belong. It's just some people have lots of taste receptors and other people don't have very many. Well, I guess the question is, do the people who have higher density of taste receptors have better taste discrimination? Can they tell two uh foods apart or beverages apart on a dimension of say sweetness that somebody with lower uh density receptors can't? So, that's a a really good question and um my I I I don't know exactly the answer to that, but what I do know is that um you would think that super taster sounds great. That's what I want is to be able to taste more. In fact, super tasters are uh especially sensitive to bitterness and to acidity to the point that uh foods that other people enjoy just fine they find aversive simply because the the sensation is overwhelming. So I used to teach a course at the French Culinary Institute no longer with us uh in New York and we would often have chefs in the uh course along with just ordinary people. The and we would do a a taste test to a a proxy for counting the number of taste buds. can give people a very bitter substance at a at a known level on a little piece of filter paper and then ask people to rate does this taste extremely bitter, kind of bitter, or what what bitter. Um, and uh, the chefs would always be uh, upset if they did not score as super tasters because super means, you know, you're a really good taster. But, um, talk to them and you find out that, um, it's often difficult for chefs, uh, to kind of match the flavor preferences of their customers. And one of the reasons for that can be that if you're a super taster as a chef, you're going to dial down all kinds of things that uh to an ordinary taster may leave the food tasting bland. So um it's something that uh there there's no right thing to be, but if you're a professional in the food world, you need to know what you are and how to compensate for it if you if you need to. I'd like to take a quick break and acknowledge one of our sponsors, Function. Last year, I became a Function member after searching for the most comprehensive approach to lab testing. Function provides over 100 advanced lab tests that give you a key snapshot of your entire bodily health. This snapshot offers you with insights on your heart health, hormone health, immune functioning, nutrient levels, and much more. They've also recently added tests for toxins such as BPA exposure from harmful plastics and tests for PASES or forever chemicals. 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In contrast, I've been super impressed by function simplicity and at the level of cost, it is very affordable. As a consequence, I decided to join their scientific advisory board and I'm thrilled that they're sponsoring the podcast. If you'd like to try Function, you can go to functionhealth.com/huberman. Function currently has a wait list of over 250,000 people, but they're offering early access to Huberman podcast listeners. Again, that's functionhealth.com/huberman to get early access to function. Do you salt your fruit? A few years ago, there was this like uh trend of salting fruit. Remember that? Um I tried it. I love fruit. I love salt. Um wasn't such a fan of salting fruit, but I don't want to dismiss it right off the bat. Does it do anything interesting to fruit in a way that should have me return to that? Yeah. I know. I I think it's it's a completely individual thing. My grandmother would salt her grapefruit. Oh, yeah. Oh, no. We would put sugar on our grapefruit when we were kids. Yeah. The sucrossse. Okay. She would salt her grapefruit. She would she would salt her grapefruit. And it turns out, we know now that in fact salt and bitter are kind of opposing um sensations. And you can actually diminish the sensation of bitterness by upping the salt. So she was making it less bitter without adding sugar, which to her was was important. She used um you know uh the the the artificial sweetener of the day in her tea in the morning. That's interesting. I I know people who put a tiny tiny bit of salt in their coffee. Mhm. To according to them, take the edge off, meaning to take the bitterness out. It makes sense. Yeah. Yeah. Based on the chemistry, this pushpull of of of bitter and um salty salty taste. Yeah. Pretty much everything in the nervous system is push pull. Yeah. And that that goes, by the way, for things like beer. Uh some people will add a pinch of uh salt to their beer. The only place in the world where I enjoy beer is um in Munich where they serve beer. Well, maybe it's the schnitzle that they're it's nearby. I love that stuff. Um but they'll come around with a heater and they'll heat your beer so that it's room temperature and it completely changes the taste. The bubbles are small in those beers. They taste to me just a little bit sweeter. And um I asked them about this and and the idea that you would drink a cold beer to them was like, "What are you talking about?" I mean, you might as well tell an American that they should um have their apple pie with um with uh spaghetti on top or something. It's crazy. Let's talk about alcohol. Even though I'm not a drinker, uh I know people enjoy a little bit of wine or spirits or or beer. And I'm I'm suppose as long as people aren't alcoholics and they're of age like you know uh small amounts of consumption are are are uh probably okay. Um zero is better. But um so let's talk about wine and beer. What's the the brief history on on this? When do people start fermenting fruit and hops and um this whole business of creating poison to ingest um because it tastes good and gets them a little bit inebriated? What what is this? So, um, this is actually an an area where we're learning more every year because people are, especially archaeological sites are pushing dates back and so on and finding evidence for this kind of thing. The the ability to detect uh residues in pots is uh is just amazing these days. But um my guess is and it's been argued that um we have been enjoying alcohol since before we were homo sapiens that really yes that primates in fact uh when you observe them will go after uh fermenting fruit and enjoy it and you know seek out and pick those fruits and not not others. And I bet uh I it's not a literature I keep up with, but I bet that there are some behavioral studies as well to in to suggest whether or not the uh ingestion of the fruit is actually having an effect on their coordination, for example. I I bet there are studies like that. Um so we've been enjoying um alcohol before we were homo sapiens. And in the archaeological record, um the dates have been pushed back now to the the very beginnings of agriculture and in many different places. So, China, uh the Middle East, um it's just um an attractive uh possibility. uh which probably did simply start with um you know collecting a bunch of fruit, not getting around to eating it right away and you know it beginning to smell interesting and you try it and it does things. Humans daring other humans to try things which I think is also by the way uh how chocolate was discovered uh or the the possibilities for chocolate. So cacao beans are the seeds in a fruit and the current thinking is that um the fruits were gathered for the fruit and the seeds which are large were simply thrown in a pile near the near the fire and uh there were enough residues of the fruit on the seeds for those residues to ferment and that's the first step in making chocolate. So with respect to alcohol, um I mean alcohol is as you mentioned a long history um I've heard it said that despite so much fascination and money spent on different wines depending on uh the make and the label and the year in particular and how the grapes were that year, depending on how the weather was that year and the soil and you know so much goes into this. It's a huge industry. Um, but every once in a while there'll be a study published where they'll do a blind taste test and some of the most experienced um, aka expert uh, wine drinkers won't be able to discern uh, the finest wine or near finest wine from a far more trivial inexpensive wine. And that always seems to send everyone into disarray for a couple of weeks and then everyone goes right back to um distributing their wine consumption according to their income and what they perceive to be the better wine. It's kind of a wild um foray into human psychology. Like if this is true that these expert wine drinkers can't discern like a $20 bottle of wine from a $2,000 bottle of wine and yet they insist on returning to the the practice of preferentially buying it consuming more expensive wines if they have the means. I mean that says all sorts of things about humans and the way we place value on things. But I want to know are the more expensive wines actually truly better from the perspective of taste and um through the lens of uh let's just say a uh a novice and an expert wine drinker. What's the deal? Yeah. Yeah. Uh so this I think is really complicated in all kinds of interesting ways. Um, and I think to begin with, it's true that people have uh done things like um serve red wines, expensive red wines alongside white wines that had been dyed red and asked people as asked experts to to judge them and comment on them and the experts being fooled by the by the food coloring. So I think it's it's in large part to begin with a a matter of what we're expecting to happen when we taste something. Uh and uh if we have expectations then those expectations are going to influence our perception. Uh and there are a couple of wonderful books by uh a neurobiologist named Gordon Shepard on exactly this uh these subjects. Um so it's it's a it's a uh um a complicated loop. We we have expectations. We taste something. The expectations play into what we think we experience. Uh and our conclusions from that experience, which is no knock on the wines. It's just the the fact of our imperfect nature as sensory beings. Uh then when it comes to the wines themselves and the kind of variation that you find uh from uh from different kinds of wine makers, locations, uh weather, treatment during the wine- making process, all all those different things. Um, if you work at it, you can train yourself to notice minute differences just as you can train yourself to notice minute differences in all kinds of other things that that we care about. Uh, art connoisseurship, for example, you know, is uh knowing something about the history of art and u and about the materials and that kind of thing. They all play into our judgment. And what we're talking about when we're talking about the the uh whether a wine is better than another, it's a judgment. And uh I think the more you know about uh if if you care to know, the more you know about uh a particular uh material, the better you're able to either appreciate it or depreciate it uh depending. And wine is just fascinating material. I mean, it's uh it's it's um made every year from all kinds of different grapes in all kinds of different parts of the world uh by all kinds of different people. And uh they all taste kind of different um depending on all those different factors. And if you're interested in those kinds of um uh distinctions and if you get pleasure from taking a sip and saying, "Ah, yeah, it was a that was a warm year in that in that vineyard and tastes a little riper than the other bottle that I have in my cellar." That's that's great. That means you're, you know, using your human capacities to the utmost. Um if you're just drinking to drink, not so much. Um, so I think it depends on the not only the the product but the but the consumer. Mhm. Like so many domains of life, it sounds like uh curiosity uh lends itself to a deeper and better relationship with something. A guest on this podcast who himself was a comedian um said exactly what you said. He said um which is only to say that you agree uh that the more you learn about something the way a movie was made or visual art or a song the more you come to appreciate it with one exception comedy. You either think something's funny or not. You can learn you can learn about the process that comedian went through. You can learn about the context and if it's not funny to you, it's not going to become funny. So it seems to be like one exception in the universe of experiences. But uh even though we weren't talking about food, I think he would totally agree with you um on this point, which is a perfect segue for my next question, which is about cheese. When you walk into a cheese shop in say Denmark or in Northern Europe, do you like it or do you feel overwhelmed? Because for those who have, they know it's intense. Yeah, it's one of my favorite things actually. Um something that I learned to like uh when our family lived in France for a year and I decided uh you know the French make a lot of cheese. I should learn something about that. And I I went to uh a little trailer at one of the farmer mark farmers markets in the little village we were living in. And in my broken French said I was I would like to learn about cheese. I got like a 10-minute lecture on how Americans could never appreciate cheese properly, but then okay, I'll I'll tutor you. And so and I had a wonderful year-long uh um uh just every every week uh a session with this cheese maker who was bringing she herself did not make uh most of the cheeses she sold but she would sell what was proper seasonally for that um for that place. Anyway, I learned a tremendous amount, fell in love with the the diversity, uh, you know, starting with basically the same material, maybe two or three different animals, kinds of milks, but starting with the same bland material and ending up with this tremendous range of flavors is uh, I think a tribute to human ingenuity to to be able to come up with that kind of diversity. How long has cheese been um, made and consumed by humans? uh since apparently very early in the domestication of animals, maybe even before animals were fully domesticated. So again, we're talking 7,000 8,000 years ago in the in the case of dairy products, that's pretty much in the in the um central Asian area. Can we talk about the chemistry of cheese and fermentation? Sure. Yeah. First, a question about a specific cheese. uh if one looks online um which is always a dangerous thing to do uh if you're in search of real information. You have to be very discerning. Um there's this idea that certain cheeses in particular parmesan cheeses are so rich with the amino acid tyrrosine that they create uh because tyrrosine is the amino acid precursor to dopamine that they create um a mild high of sorts. Um now this of course could also be that people just really enjoy the taste or both. Yeah. But makes sense at some level. What's known about the chemistry of cheeses and um the experience of cheeses? Yeah. Well, so the the the thing that makes cheese much more interesting than milk is the fact that um microbes have been living in it and on it for um weeks or months or years and slowly breaking down the proteins and the fats and generating these small molecules that we were talking about before that have flavor that uh that give us the sensations of taste and smell. The longer that process goes on, for the most part, the more of those breakdown products there are and the richer and more more varied the flavor is. Now, you can sometimes get very strong flavored cheeses very quickly. Uh cam bear is an example of uh cheese like that where you um in the cheesem process essentially encourage the changes to happen very rapidly. But if you um dial back on the process and let it take longer, you end up with a much more diverse uh array of array of molecules. And in the case of Parmesan and the those crystals that you end up with in cheeses that are 2 three years old um uh which are crunchy and kind of uh they're the the sign of authenticity you know that this cheese is actually that old and uh it's worth paying double the price that you would pay for a young version. Um those are uh usually uh tyrrosine or other amino acid um um derivatives that are uh that have been broken off of the protein chains and then because the cheese has slowly been dehydrating u they've become insoluble and begin to crystallize out. And so that's why they're a sign of um uh of the process of aging and also the the time of aging. Um the thing about it though and the for me the question mark is uh that tyrrosine was there already in the proteins and so is having it crystallize out somehow making it more immediately available to have an effect on us? uh you know we don't have to digest the protein anymore now. It just you know pops right into us the moment we put it in our mouths. Maybe that has something to do with u the effect that people are reporting. When smoke flavors are added to cheese. Is it through actual smoking process? Yes. If it's authentic. Yeah. If it's authentic. Yeah. the cheeses have been um kept in a room with something smoldering and that was often in the old old days and still to some extent these days kind of like um curing hams uh bugs are going to want to uh enjoy that really rich nutritious material and so you have to ward them off and smoke is a good way to do it. Ah that makes sense. So to keep bugs away, you fill the room with smoke and then you end up with food that tastes smoky. Yeah. And then you tell people that it tastes good. I'm not a fan of smoke. I don't know why. Yeah. Maybe it's because most smoky flavors seem to come from a kind of a It tastes chemical to me. It doesn't taste like smoke. It tastes like a tastes like um smoke generated from uh um drywall mixed with uh some styrofoam. It doesn't it doesn't it's not it's not like a nice uh organic in the real sense of the word um natural flavor to me. It tastes chemical. Yeah. Yeah. No, I I I know exactly what you mean. I also think that most smoked foods are oversm smoked. You know, that that ends up being the only flavor that the food has and instead of being a kind of in the background uh flavor. So, and what about in bourbons and things like that when people get really excited about a smoky bourbon? Is that um why would you do that? Because I can't imagine that the bugs are going to get into Well, bugs like ferment, right? Is that right? Um actually, one great way to attract bugs to your picnic is to have vinegar there. They love Yes. the smell of vinegar. Yeah. Yeah. So, in the case of um uh barrels for distilled beverages, that's a uh as far as I can tell, just a completely cultural thing. You know, that um in order to make barrels, you have to uh heat them in order to make the wood pliable. Mhm. And probably someone in the process of making barrels discovered that if you, you know, if it burns out of control for a few seconds, that may be not such a bad thing 10 years down the line. So, um it's certainly not essential to the flavor of uh of alcohols. And a lot of, for example, um whiskies may may be marketed as having been aged in used cherry casks. So you don't get the the toasting that you get if you're making fresh perils. So I think it's it's a matter of taste and and also just the the skill with which that flavor has been incorporated into whatever the the food or drink is. On the topic of fermentation, our colleague, I assume to be mentioning a lot of our colleagues, but we've got a lot of spectacular colleagues at Stanford at Justin Sonnenberg and to be fair, his wife Erica, who's also contributed critically to this work, have uh made discoveries essentially that consuming low sugar fermented foods on a daily basis can lower inflammation, markers of inflammation even more so than increasing one's fiber intake, which is itself interesting. What have you learned about fermentation chemistry? Fermentation as a as a human practice. Um, for health benefit, sure. For taste, but just as as a thing. Fermentation is a pretty pretty wild thing that we would do this. Yeah. Yeah. Yeah. Well, so I uh my sense is that it began um we were talking earlier about uh about alcohol began with just observation. you um have fruits that are overripe and they're sitting on the forest floor and they sit long enough and they begin to smell different and look different and fizz and all kinds of things and that's that's interesting. So, um I my sense is that fermentation has been discovered essentially by every population on the uh on the earth, including the the Arctic, where you think it might take a while for things to go on. But in fact um products that are translated into English as stinkfish are among the most prized of the of the foods in the Inuit um regions of the of the pole. How do they prepare the stink fish? Uh essentially by uh letting it sit. So that's one of the appeals of fermentation is you don't have to do a whole lot. you just uh catch the food, whatever it is, and um um put it in a container of some kind. Uh some stingfish are made simply by digging a pit and burying it and covering it over. Um and then there's there's a connoisseurship of of these foods. Um it's a lot of fun actually to go back and read the accounts of explorers to these regions and the the locals are you know uh trying to show the greatest hospitality by serving them foods that they can't bear even to get near. Um uh salmon eggs another example highly prized uh but after they'd been fermented. So uh this is caviar. Yeah. Yeah. Caviar. the most expensive foods on the planet. Exactly. Exactly. And not just for um kind of for show reasons. I mean the the omega-3 content of caviar is like off the charts and the um there are other micronutrients in in caviar that make it this is like the these are the sturgeon eggs typically, right? Yes. Yeah. That's right. Yeah. Yeah. which uh production of which almost disappeared 20 years ago and now is booming because people are now farming these fish. The fish were endangered. Uh they're now farming them all over the place and trying uh caviar from different species that had never been tried before. So um uh that's actually part of um what I would say about fermentation these days as well is that once um the the formerly isolated populations on the earth began communicating with each other and sharing expertise and sharing knowledge of these materials which has happened of course um hugely in the last 20 years or so. Um local traditional ways of doing things have now not only spread to other parts of the world, but gotten people to ask the question, well, if you can do this kind of fermentation with this raw material, what about doing it with a different raw material? Um so um you know miso was traditionally made with soybeans. Now it's being made with peas in in uh northern Europe and just on and on and on. um uh which I think is both tremendously difficult to keep up with but also tremendously exciting because it means that we're now um seeing how traditional food materials can be transformed by the action of microbes that we've we kind of know about but only know about in very specific uh contexts. Uh and so I I think the next couple of decades are going to bring forth uh just all kinds of new foods that will be initially strange and maybe off-putting because they're new, but also they're going to be, you know, this this era's um versions of miso and uh soy sauce and beer and wine and so on. So exciting times ahead. Yeah, we we forget that we're still evolving, you know, especially when we hear about all the problems of the world. We we forget that we're still evolving and that some of the technologies around food and drink are not just creating less healthy versions, but as you pointed out are are creating new new hybrids of information, new hybrids of actual foods. It's not all about returning to ancient ways. you know, the conversations like this of slowing down and and one's intake of food and chewing and appreciating and um thinking about preparation of food, not just eating out of packages. One hopes um people I think if there's one thing that the vegans, the vegetarians, the omnivores, and the carnivores all agree on is that eating fewer processed foods is better. That's the one thing they all seem to agree on. Yeah. Um I have a question about you. actually have several questions about you which is what motivated this exploration into into food and chemistry. I mean you're taking a very different approach to all of this. Um I should point out that your original training at Caltech was in astronomy then you shifted to another field and then you ended up in this field of of food science chemistry. um you know a lot about poetry. So um I don't think I've ever met anyone with that background. You are clearly an N of one as we say. What what got you into this whole thing? And and and more importantly perhaps what motivates you like what's what's where's the the texture of interest? Yeah. Is it like to taste as many things as possible or is it to link levels of analysis? What what is it? That last question is a really good one. And I'll have to I'll think about that as I answered the first parts. So yeah, I started out um in love with science and with astronomy in particular and you know built a telescope and um uh I still look up at Orion every time it's in the sky and the and the skies are clear. Um went to Caltech to do astronomy. decided after a couple of years there that the um the physics was just not enough of a motivator for me to keep going. The physics had at that point had gotten pretty um hairy for me. And so I decided, you know, I I still love to look at the stars, but maybe I'm not going to do astronomy. I then looked around for other things. and the people I I had always loved the humanities, poetry and novels in particular. Uh I was going to transfer to Stanford actually and my uh literature professors at Caltech and there were a few um convinced me to stay and they said what you can do is you can stay with us cherrypick the science because you don't have to take as much anymore and we'll get you a desk at the Huntington Library and the research library and we'll we'll give you tutorials and we'll take care of you And that's exactly what happened. It was a fantastic um uh education that still included plenty of science, but it was on my terms and not the not the discipline's terms. Uh and then I went off to graduate school in literature uh having been um uh inspired by my teachers at Caltech. did a degree there uh on the poetry of John Keats uh and then couldn't get a job teaching and so my um my mentors back at Caltech and also at in graduate school said well you know you have the science in your background you should do something with that and um long story short conversations with friends over the dinner table and drinking wine and so on um a question came up. Why is it that beans give you gas? And uh we all laughed. I laughed and then I went to the library and I found out why. And I came back and told my friends and we had a good laugh. And then I thought maybe I mean people are interested in food and this is kind of a fun fact about food that most people don't know. maybe I can do this kind of thing. Uh, so I began to look a little more into it. And then in the meantime, a scout for one of the publishing houses in New York had a girlfriend who was in the same group and she reported to him. He reported to the publisher. Publisher called up out of the blue and said, "We hear you're writing a book about the science of food." And so from that moment on, I was writing a book about the science of food. I He said, "Yes, I am." Yes. Uh why why do we get gas from beans? And is it true that soaking them in water prior to cooking them can uh remove some of that unward effect? So it turns out that the the answer was discovered by scientists working for NASA. And if you think about NASA and their missions back in the 70s, you can understand why they would want to control something like this. So, uh it turns out that beans contain in addition to uh starch and sugars, uh kind of intermediates, uh carbohydrates that our bodies do not have the enzymes to break down into sugars. So we can take care of starch but but not these um intermediate size molecules and so they pass into our gut unchanged and then we have plenty of microbes who are happy to see those and and uh digest them and in the process they produce CO2 and hydrogen gas and that's what we end up experiencing. So the way to deal with that is to uh soaking the beans will work. Um that leeches out some of these molecules which are small and so soluble in water. Um even more effective is to actually bring that water after it's been soaking to a boil and then pour that water off. That that will get rid of more. But the other point I would make about these uh so-called oligosaccharides is these days we value uh the life in our lower tract and these are the creatures that those molecules are in fact feeding. So and it has been shown that you can you can uh or your system can kind of adapt. Uh so yeah, the first few times you have uh um beans or light lentils or whatever it might be, um you may have some discomfort, but the more frequently you eat it, the better you're able to tolerate it or your your system is able to tolerate it without generating the the discomfort. Yeah, that seems to be a repeating theme, which is that the more we eat certain foods, the more our gut microbiome adapts to those foods. I think that we're just at the beginning of understanding the gut microbiome, but it's such a key player. So, what um do you make it a point to eat fermented foods um given what you know about the microbiome? What are your favorite fermented foods or drinks? Yeah. Um, I uh have learned to like kimchi. So, that was not initially uh a food that I sought out, but I I've really come to like it. Um, and um uh you know, that that may really be the only uh unusual fermented food that I seek out. I mean, I um I love fruits and vegetables and and legumes and eat lots of those and kind of figure that, you know, things will take care of themselves down there for the most part, but uh kimchi is something I've come to love. Yeah, I haven't quite gotten to the kimchi thing. I I think it's because a few years ago I brought it into my lab when I was in San Diego and my entire lab complained except one person, my Korean student who absolutely loved it. So I think some of these things are are acquired early in life, right? And that's a question I was going to ask earlier. Do you think that when young kids in particular like don't want broccoli or they um don't want certain foods that it's reflecting an actual real aversion that's based on something important about their chemistry? Yeah. Yeah. So my uh again I don't think the literature is clear but my sense based on having had a couple of kids go through this and just thinking it through. Uh I I think what's going on is that kids have a heightened sense of taste and smell. Um and very early in development they're um omnivorous. They're they'll put anything in their mouths. then at a certain point they become much more conservative and um and I think also much more sensitive to nuances you know the sulfurousness of broccoli and that kind of thing. So um but I think it's also uh both temporary and uh you can work with it. So in the case of our kids, um we just made our regular dinners every every day. Um and we would say to our kids, you're welcome to eat as much or as little of what we have as you want, but this is what we have. And there was one food that neither my son or daughter could tolerate. And we ended up just deciding, okay, that's literally off the table. you don't have to worry about this one. And it was um amaranth leaves. Whoa. Uh which I was growing in the garden cuz you know I'm trying to learn about everything and uh and they're interesting. Uh but they have a very particular texture and it was the texture that they just you know it made them gag and I didn't want to put them through that. So fair. So it wasn't just saying I don't like this. It was they were trying. If nothing else, one can still thrive uh in life without having eaten amaranth leaves. Is it true that some people like and some people loathe cilantro because they taste different things in the cilantro? Like the experience of cilantro is fundamentally different for some people than others. I like it. My father, he he hates it. Yeah. Yeah. Yeah. So cilantro is a really interesting case and um the subject of a series of uh studies at the Monell Chemical Senses Center. Uh they were they in addition to all kinds of other things would go to local county fairs and ask people a ask first of all for twins. if if they saw twins on the grounds, they would bring them over to the booth and ask them both to taste uh cilantro and and say what they thought. Bottom line is um um cilantro has molecules that uh kind of uh I was going to say crossreact. That's not exactly it. They they're also found in soaps. And so for a lot of people, depending on whether they've been acculturated to cilantro early in their lives or not, if they're only encountering it as an adult, the first thing they're going to think is that tastes like soap. I don't want to put that in my mouth. Uh unless, you know, you're in company where it's important to go along with the with the gang. Um, so there's a good uh basis for this kind of divergent set of reactions, but it has more to do with the the cultural appearance of those same flavor molecules than with the material itself. I see. So for those of you that don't like cilantro, you can uh cite this uh discussion. I have a colleague at uh Harvard um Katherine Doolock who studies the oldactory system. You're probably familiar with Katherine's work and um she's French uh as the last name suggests and she would tell this story about different students and postocs in her lab who come from a variety of different countries um being split down the middle in terms of their experience of microwave popcorn. that some people in her lab like love the smell of microwave popcorn, but then there's a separate population of people in her lab that experience the smell of microwave popcorn as exactly the same as pungent vomit. And she claims it's on the basis of a variant in one of these olfactory receptors, which also speaks to the relationship between smell and taste. You know, like nobody wants to eat something that smells putrid. Yeah. Yeah. Generally, one would hope. What are some other examples of foods where people tend to diverge on the basis of something uh known to be or almost certainly biological as opposed to just I wasn't raised eating that or that seems weird. So, one thing that comes to mind that isn't quite that um is u parmesan cheese, which um has as one of its primary uh flavor components butyric acid, which is also the main thing that makes vomit smell like vomit. And some people uh just can't eat Parmesan cheese for that reason. Others don't notice it. Uh others kind of notice it, but it's okay. It's part of being parmesan cheese. Uh so a lot depends on not only the sort of the individual apparatus experiencing of food but then also what's kind of normal for that food to contain. And because um uh cow's milk is especially rich in um butyric acid as one of the components of the fats. That's what you get when the the breakdown takes place. I like the example of Parmesan and cheese. More for me. Yes. More for me. My last question is um not in the domain of food or chemistry, but um it's about poetry. This is a science health podcast, but you're here and and you have the expertise. So, I'm going to ask you. I love poetry. What is something that you learned about Keats that most people don't know that is at least to you particularly interesting? and then I'll ask you to suggest uh a Keat starter pack. Um maybe name one one Keats poem that everyone should go read. We'll put a link to it. But first question is uh you spent considerable amount of time researching Keats and learning about him and his work. So um what's something that we're not going to learn elsewhere? Yeah. Yeah. Uh I think one of the most important things about his his development uh and the reason that he wrote the kind of poetry he did which was often um concerned with uh with death eventually ultimately um is that he started out life as a medical student. He was a medical student at uh uh Guys Hospital in London which still exists and has a long um uh amazing history. Um he was a medical student. He uh had a mother and a brother who both died of TB and he attended them uh in their illnesses. And uh so to know that and then to read uh a poem like to autumn which is the the poem that I would uh uh suggest people read I think just adds a dimension of um um uh appreciation to that poem because there's there's nothing about death in the poem. It's just a description of a natural scene in the autumn. Um but that those experiences are there and uh knowing that and reading not only that poem but but many others um I'm sure it was um well I I think he wrote poetry both to um comfort people and to kind of work through what it is that life is all about that he needs to come to terms with in order to have lived that that life. Thank you for that. We will go read uh to Autumn and uh we'll look for those experiences uh inside of that. Couple of things I want to say. Uh first of all, uh thank you so much for coming here and and sharing your knowledge with us. Um I'm certain that it's going to change the way that people experience food and drink. And if nothing else, we'll get them chewing their food and pausing between bites here and there to get deeper into the experience of food. Uh it's also nice uh in fact, it's very refreshing to be able to talk about food uh on this podcast uh not within the context of just fueling the body and health benefits. those are critically important, but obviously food has cultural aspects and it has taste aspects and is one of the great sources of pleasure in life. So, um you've taught us how to get more pleasure from from food and also its links to history and human evolution. I mean, there's there's so much there and we'll put links to your books that explore uh chemistry of food and and other other aspects. I also just I want to thank you because whether you intended to or not, um you're a wonderful example of how somebody uh follows their interests and blends them um and how talking about your interests with people um can help you get opportunities to get paid to do what you do. You know, people often wonder, you know, how do I take my varied interests and and put them into something? And they'll try and like like thread the needle from this to that. And and I I'm not going to make up a story here, but what I gathered was that just by being you and being open-minded and answering questions when people ask that uh you've been able to uh braid together your your interests in a way that's allowed you to have a very unique career that's very impactful. Your books have been read by so many people and this conversation will be heard by so many people. So, thank you for that. It's a reminder to just be oneself and things generally work out and that you're continuing to do the the great work that you're doing. So once again, thanks for taking the time to come down here and talk to us. I'm going to try some new foods. I think I'm going to do this tea thing. I need some greenery in my place and I'm I think I'm going to do that. So I have questions for you about that. And um yeah, thanks so much. I really appreciate the work you're doing. Well, you know, thank you very much, Andrew. If I can just say a word um about how um how rare it is to talk with people who are broadly interested in sort of the details of life but also the meaning of life and you know what's what's possible and what's not. Uh that um that makes me especially happy to be here. Um, and I was just going to say that, um, I looked at this the book about food as being, you know, a oneoff and then I would write about gardening or, you know, something else. Um, and I just got captured by the subject. You know, there's it's hard to think of something that's more central to um, you know, just sustaining human life, but also getting pleasure from it. And uh so I I went down the rabbit hole and I'm still down there. Oh, we're grateful you are. So, thank you and thanks for putting the knowledge you collect in that rabbit hole out into the world. Thank you. Thank you for joining me for today's discussion with Dr. Harold McGee. To learn more about his work and to find links to his books, please see the show note captions. If you're learning from and or enjoying this podcast, please subscribe to our YouTube channel. That's a terrific zerocost way to support us. In addition, please follow the podcast by clicking the follow button on both Spotify and Apple. And on both Spotify and Apple, you can leave us up to a five-star review. And you can now leave us comments at both Spotify and Apple. Please also check out the sponsors mentioned at the beginning and throughout today's episode. That's the best way to support this podcast. If you have questions for me or comments about the podcast or guests or topics that you'd like me to consider for the Huberman Lab podcast, please put those in the comment section on YouTube. I do read all the comments. For those of you that haven't heard, I have a new book coming out. It's my very first book. 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Thank you once again for joining me for today's discussion with Dr. Harold McGee. And last, but certainly not least, thank you for your interest in science. [Music]