The Infinite Monkey Cage - The Science of Cooking

Episode Date: February 1, 2021

The Science of CookingBrian Cox and Robin Ince get their chef's hats on as they look at the science of cooking. They are joined by comedian Katy Brand, author and food critic Grace Dent, material scientist Mark Miodownik and science writer Harold McGee, whose seminal book on the science of the kitchen launched the craze for molecular gastronomy. They look at some of the lores of the kitchen are backed up by the science, and ask whether a truly delicious dinner is really a science or an art. Is cooking just chemistry?Producer: Alexandra Feachem.

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Music, radio, podcasts. Hello, I'm Robin Ince. And I'm Brian Cox, and this is the Infinite Monkey Cage. Quantum physics has a rich and varied history when it comes to its involvement with international cuisine, including Nobel Prize winner Richard Feynman's lauded experiments with pasta. And this is entirely true, by the way. One evening, breaking a brittle piece of spaghetti

he wondered why it broke into three pieces rather than two and he immediately invited all of the finest brains of Cornell's physics department to bring around as much spaghetti as they could get and they spent the night breaking spaghetti and applying equations to it and at the end of that evening they had come up with

no answers whatsoever but they did have a very good bolognese. You know what? Sometimes failure followed by bolognese, it's all right, it's OK. Apart from that, the only other big physics meets food story is obviously when the Large Hadron Collider had to be shut down because someone dropped a sandwich in it. Apparently, this is true. Coronation chicken slows down the path of bundles of subatomic particles,

though there are no papers on the effect of egg and cress on protons. Today's show is about the science of food and cooking. For example, Robin, can you identify which food I'm talking about now? Pineapple notes from the presence of ethyl esters, sulphur compounds and a complex caramel-like oxygen-containing ring. And for smaller European woodland varieties, a flavour of concord grapes, thanks to anthra-nylates and clove-like spices from phenolic eugenol. I'm going to go with a lion bar.

Is it a lion bar? It's actually strawberry. It's a strawberry, dead or alive? Don't start that. It doesn't matter anyway. In today's show, we ask, is cooking a science or an art? To make the perfect meal, do we need to understand anything beyond the chemistry of its ingredients?

Should Michelin be replaced by Mendeleev and Nigella Lawson by Lavoisier? And I'll be working on a new show called Rusty Lee equals MC squared. To discuss the scientific revolution in catering, we're joined by a man who came to chemistry via Keats, a professional critic of consomme, a materials engineer with a deep understanding of marzipan, and a theologian seeking the perfect recipe for the communion wafer. And they are.

My name is Harold McGee. I write about the science of food and cooking and now smelling. And the greatest thing I've ever tasted is a plump, perfectly ripe, aromatic Florida mango. My name is Mark Miodovnik. I'm a materials engineer. And I went for not the greatest thing I've ever eaten, but the strangest thing I've ever eaten, which was a live octopus tentacle served to me in a South Korean restaurant. And it's so odd to have something in your mouth that definitely does not want to be eaten and is trying to get out. My name's Grace Dan. I'm the restaurant critic for The Guardian. You might also know me from

MasterChef. I've got a book out called Hungry. The greatest thing I think that I've eaten that I can remember currently roasted pink fur apple potatoes, roasted on an oven bottom so they're gorgeous and smoky and then dipped in creamy cods roe. That's one of the greatest things. There's a restaurant in East London and you only get five in a portion but I think I could eat 75 no but I'm a northern woman I like carbs I'm Katie Brand and I'm a comedian and writer and I've eaten lots and lots of great things so I thought I would pick something that's consistently great to me which is a boiled egg which I have every morning and I always give thanks to the egg and celebrate its little miracle it never gets tired for me I always like to have a boiled egg.

So that's my choice. This is our panel. Shouldn't you give thanks to the chicken? It depends. I mean, it's a bigger question than perhaps you know, Brian. A deep question to begin with. That's a whole show. Harold, I have your book here i should say

um which is the only cookbook that i've ever used because it's not really a cookbook it's a textbook it's it's a book that explains in great detail why you might consider cooking things in a particular way but doesn't actually tell you what to do so i wanted to ask you whether cooking really is all chemistry, basically, because that's what this book, this is why I love this book, because it basically says cooking is chemistry, which is essentially physics, and so therefore all cooking is physics. Is that a fair summary of your position? Well, I would actually move in the other direction and say that biology is important too, so we wouldn't have the other direction and say that biology is important too. So we wouldn't have the ingredients if it weren't for living things.

Chemistry helps a lot in understanding what's going on and getting the results that you want. But you also have to know what it is you want. And that's a matter of your upbringing, what you've experienced, what you'd like to experience. So I think cooking kind of brings together everything that there is about being human and makes it possible for us to explore the nature of the world around us, the materials that we work with every day and the things that nourish us. Can I ask you, Harold, I find it fascinating that you were an academic really in the area of literature and you were, you know, Keats in particular, who of course famously wrote about Unweaving the Rainbow.

And then your first book was all about suddenly you're embracing science. So how did those two things, how did you find that link? Well, actually, I started out in university studying astronomy. So I started in science. Where did it all go wrong? But Brian, I came back to it. You know, I just put a G in front of astronomy. So I'm

still there. See, I'm a bit thrown because Brian said this is his favourite cookbook. But I've never, every time I've been round your house, we've had a takeaway. So I want you to write... Do you just like it because it's a textbook or have you actually used that? Come on, what have you made?

It's not... I mean, one of the things I love about this book... No, I... For example, one of the things I learnt was that, which appeals to me, is that how would you cook a perfect steak? You know, how do you cook meat? And I think I found in your book that a good way to cook it is very slowly, very low temperature.

So put the oven at about 60 degrees or something and then just cook the meat until the interior is around 56 degrees Celsius or something like that. And then take it out and eat it. And that's the kind of cookbook I need. I just need to know if I put a temperature probe into the middle of the meat, what should the reading be when it's ready to eat? And that's what your book does. So I could ask you actually,

why is it better to cook meat slowly or different? Why does it lead to a different taste than cooking it at a high temperature? Well, the challenge for cooking meat at a high temperature is that the cooking temperature is much higher than the temperature you want the center of the meat to be at. So you have a grill that's maybe several hundred degrees, and you want to get the inside to, yeah, 50 degrees or something like that. That's a huge differential. And so if you bring the outside temperature down

so that you can control it, then you can end up in the zone that will give you exactly the doneness you want very easily. And that's the thing about cooking is that the more you understand about it, the better you can control the processes and get the result that you want. It's all thermodynamics, Mark.

But yeah, Harold's missing out the bit that makes those steaks so delicious, which is this Maillard reaction, which he also talks about in his book so brilliantly, which is this reaction between these proteins and the carbohydrates that gives this wonderful sort of, it's the same sort of smells and tastes you'd get from baking bread and from beer. And that taste sensation is one of the things you're looking for in a great steak, not just the texture on the inside of a perfectly cooked steak. And getting the two together is the real challenge for a top chef or anyone trying to cook a steak at home. And we had a go at this by trying to have the best of both worlds. We

deep froze a steak to liquid nitrogen temperatures and then plunged it into a deep fat fryer. Now, in theory, what should happen then is as the steak heats up, by the time the deep fat fryer has heated in the middle to 55 degrees, the outside has been perfectly Maillard reactioned at high temperature. So you pluck it out about 14 seconds later and a perfectly done steak. Now, that is the power of science. I'm sure Harold would agree. Especially the 14 seconds part. I'd love to be able to cook a steak in 14 seconds. See, that's what I love about it.

The image I now have of people like, you know, Brian and Mark in their kitchen is not that you do the main bit of cooking but like brian's there an eager boy with his temperature probe while someone else does all the hard work can i put my probe in yet not yet brian but grace you i mean i'm as a restaurant critic when you start hearing these things about you know using liquid nitrogen we've heard more and more of these. What's your initial reaction to this science meets food moment? Look, if I'm very honest, as someone who has to eat out hundreds of times a year, it makes me slightly deflated. Because, you know, although I am very, very respectful of this cookbook, this textbook, and all the work that's been done, all the wonderful things we're going to talk about tonight,

when I have to go out and I get 19 courses of this, it can be quite a long evening of people coming in with chronicle blasts, cloches, smoke. And, you know, I think that anybody that keeps you there for over 17 courses of that, I think it's really just technically kidnap because I can't leave. Because if you try to go, they're so upset. I think that listening to all of this, though, I would agree that I think that food definitely needs science. I think puddings are a science.

But food definitely needs science. I think puddings are a science. Puddings require exact proportions and things to happen at an exact time. That's my argument anyway. Is the one thing that you sometimes, of all the special effects while you're having your 17-course meals, of all the different props that are brought out, all the different moments of fire or freezing temperature, is the one where you go, oh, no, not that again?

I just think anything with either a foie gras, I just think that for the amount of cruelty, it should just taste less like snot, to be quite honest. I just think it's just... I think I was going, now we've got the foie gras and we've done this and we've done that with it and we've pulled it through this and heated it up and it's like, oh, here we go again.

What we might have found out there, Grace, is that you've got a bit of a reputation as a restaurant critic, and you go, what's that? Grace Denton, have him a foie gras, has she? Hang on a minute. There we go. That's the foie gras. There we go.

That's for the two-star review in The Guardian. I think it's interesting when we talked about biology being involved, though, because when you talked about making that steak and, you know, was it 14 degrees and you plunged it into something and you brought it out? I think that it's biology that would say whether you actually found that perfect. Thousands of people would have said that was awful. Steak is a very, very divisive and personal thing, which I think links into psychology. Millions of people like it blue and bloody and some people it would it would repulse them. So, yeah, yeah, I think that, yeah, it's all to play for. That's what makes it interesting.

Well, that that's the multisensory component of the science as well. of the science as well, I'd say too, is that many chefs understand that very well, the fact that it's the sound and the look as what you taste. And sort of famously, Harold can tell us more, but famously Charles Spence, who's a psychologist who works in Oxford, done some great experiments where he played around with the sound in your headphones as you're eating food, and you can change how much you enjoy it quite a lot uh and crisps is a very good example

um you know like a crisp isn't a crisp unless you hear the crackling of the of the wrapper it's so much it's so much crispier and if you if you have a pair of headphones and you put a crisp in your mouth and you can't hear it crisping, you hate it. It's a disgusting taste. It's a disgusting sensation. I think I'd still give it a good go, though. So, Katie, what about you? Are you someone who loves this idea of that kind of... Because within all the skill of this, it is a show, isn't it? Yes, and I have to say I do sympathise with Grace

and agree with her to some extent with the kind of microbiology, gastronomy sort of hostage situation that she describes. And I once did go through one of those at a very famous Spanish place that was known for this sort of thing. of the waiters bringing more cutlery because we we didn't know how many courses there were in this tasting menu it was entirely up to them and and we were sat there like horrified after about three hours just going they're bringing because they cleared the cutlery after every course and so they would walk over ominously with more cutlery, and it was just... We were sort of sat there going, is that more for us? More? Oh, God.

Oh, God. It's going to be... I don't know. Also, there's that kind of fear where you go, now they've brought me a machete. Where does this go? I don't want a hammer. I don't want a tiny hammer. I don't want it.

But they... I don't want a tiny hammer. But they did bring out this quite exciting thing, which was like an olive. It looked exactly like an olive, but it was actually an artificially created membrane with olive oil injected inside it. And when you put it in your mouth,

it burst like a kind of a teaspoon of olive oil, which was horrible, but very impressive in terms of technology of it um but this is the trouble is that it was all exciting and sort of interesting but half of it was not very nice so and then obviously at about an hour later you just really want a bowl of chips so um whilst i sort of admire the scientific endeavor and it is exciting and of course it brings new exciting flavor combinations sometimes I just want to sit down and eat something on a plate and then have the plate taken away and then they bring me pudding and a spoon and that's it

but do you not find it inspires you too I mean just knowing about the the way in which a different place or a different combination things can make something taste something ordinary taste amazing really allows you to kind of play with it and so the best meal we cooked over lockdown without a doubt we all agree on this is when we cooked fish and chips and went onto the roof and we wrapped them in paper and ate them on the paper in with the setting sun and honestly it was as close as we could get to being on the beach and it was like being on the beach and we loved it we all loved it and uh you know on the beach. And it was like being on the beach. And we loved it. We all loved it. And, you know, just that was simple. But it was also just, you know, just playing with a few different elements, you know, the place and the wrapping of the paper.

I think it's so easy to be cynical about it. And I am cynical sometimes because I'm very spoiled and I have to eat it all the time. But it doesn't matter how cynical I become. Some chefs, Simon Rogan is a very good example. He had olives in clarages for a while. And, you know, he says, oh, I'm going to bring you this thing. I'm going to bring you this dessert. And, you know, it'll remind you of being a child.

And you just kind of laugh. And then you eat it. And it reminds you of being in, you know, on a caravan holiday with your gran in 1973. But what if you don't want to be reminded of being on a caravan holiday with your gran? There you go. What if you don't want to be reminded? Before you know it, you've kind of got tears streaming down your face. Then that's just caravan holidays.

Harold, can we begin to talk about the different components of enjoying a particular food? I mean, Mark has talked about the sound and the crispiness and the location and eating fish and chips and paper and so on. But in terms of the chemistry, the taste, the smell, the different things that go into the experience, the texture, I suppose. Could you run through those different components? Well, tasting food kind of brings all our senses together. And I would say that the two most important of all of them are, of course, taste and smell. And I think of taste as being kind of the foundation of flavor. We have a limited number of tastes that we can

detect on our tongue, sweet, sour, salty, bitter, maybe a few others. There's some debate about that. But then when it comes to the wonderful variety of flavors, it's really smell that is most important. We have several hundred receptors for different smell molecules. And when we smell something, we're actually detecting little bits of that thing, molecules that are escaping from that food or that material in the world, and going through the air so that we can breathe them in or breathe them out. And as they pass through the nose, there are these receptors that can detect them. The receptors then report to the brain, and we end up with what I like to think of as the building on top of the foundation, the superstructure. So the taste sensations are the foundation. The aromas are

what makes different foods what they are, makes them individual. Can I just say, it's very interesting to me all of this, because I had a bout of COVID-19 back earlier in the year. And as many people out there will know, one of the symptoms is losing your sense of smell. And it was the most extraordinary experience. I'm sure many, many other people have experienced too by this point, but for a good 10 days, I had no sense of smell whatsoever. And I think some people who haven't had this particular symptom of this particular virus think you just mean your nose is a bit blocked up or you've got a runny nose and think oh yeah I had that when I have a cold but I had none of that I just literally couldn't smell and I only initially noticed um because you know I'd

started on this regime by chance of kind of taking a good probiotic and doing all these things and and trying to take better care of of my internal health and all of this and i initially and i went to the loo for let's call it an elimination and i couldn't um detect any evidence whatsoever and i thought gosh this probiotic's amazing i'm like a sort of spotless inner tube inside there's this is like i i i'm just sort of it's just purified water coming out of me there's no but and then I realized oh no I can't smell anything at all and it was quite interesting and amusing for a couple of days um in the sense of I couldn't I'd try and smell my coffee I put that right I'd try and smell very spicy food I put my face right I tried to smell all kinds of

it was like a sort of circus act for a short period. But after that, I started to become quite depressed. And I thought that was quite interesting, as I'm sure scientifically you guys will know much more about this than me. But it definitely affected my mood. I mean, the fatigue came with the illness anyway. But not being able to smell anything or taste my food, especially in lockdown, suddenly just removed a whole pleasure that was open to me for a good couple of weeks and it absolutely it made me very very depressed see i'm fascinated i don't know if mark i'll ask you about this because because mention that my mum unfortunately suffered a brain injury which meant she couldn't uh smell either but she was still able to cook very well

she was a very good cook she made lovely things and yet from everything that i've been told that you once the smell's gone the effect people may have done this at home where you do that you hold your nose and you and someone pops a sweet in your mouth and you can't work out the flavor and it's a fascinating thing that all of that is working together yeah so we we investigated this with um some spoons so we made spoons of different materials and and got people to blind taste test and see if they could guess what the material was from just the taste. And it turns out your mouth is a very, very good detector. I mean, as Harold was saying, has a very sophisticated apparatus to tell both in terms of flavor and the olfactory senses of what material is made of.

Even gold, which is a very inert material, they could definitely tell the difference between that and chrome and stainless steel, which is an amazing thing. And when I gave a talk about this at one point, as a result of the scientific paper we published, a doctor came up to me afterwards and said, do you know that loss of taste and smell is an indicator of illness often? And in fact, not just in this case, it was COVID and flu, but it can be also of cancers.

And he said, if you could perfect a standardised taste test that everyone could take every morning and know whether their taste senses are at equilibrium, then you would really have a big input for the medical establishment because a deviation from it

is a big predictor of illness. And so we thought, wow, that that's amazing so imagine you had a spoon and every morning you took you ate your cereal out of it but it had a particular flavor and every morning you just went checking yes tastes slightly of aniseed and metal and something else i'm healthy oh Oh no, I need to go to the doctor. Harold, I know you talk in your book about the way that a copper-bottomed pan, for example, will react chemically when you're cooking. So I think it's particularly with sprouts and things like that that you change the flavour. Could it be the same here that Mark's talking about is it possible that a spoon made of a

particular substance can change the the experience of food because it seems difficult for me to understand the mechanism well it's certainly true that metals can be very reactive and that means that they can react with the things they come in contact with and with our own mouth. So you know how if you bite your tongue by accident or if you're eating a particularly blue steak, there's that kind of metallic flavor. But metals, in fact, can't fly through the air in the way I was describing. For something to have an aroma, it has to be able to get into the air, and metals are not volatile in that way. So what we're actually smelling, what we're actually experiencing, tasting, is the effect of the metal on the components of the food, or if we've just bitten our tongue, the components of our mouth.

So it's a very indirect thing in the case of aromas. But then, as Mark said, metals do dissolve into foods, dissolve into saliva. And so we can taste the ions in our mouth. So we can get it both ways as taste and as a kind of indirect effect as an aroma. Silver cutlery is particularly weird on this front because, you know, silver is held up as the thing where everyone should have, you know, a canteen of silver cutlery used to be the wedding gift, like to kind because, you know, silver's held up as the thing where everyone should have, you know, a canteen of silver cutlery. It used to be the wedding gift, like to kind of, you've made it,

you're totally middle class, upper middle class probably. And then, so at Christmas time, everyone gets them out if they've got them. But actually from our tests, it's actually, it inhibits the flavour of many foods and a silver spoon with tomato soup is awful in my view. And actually stainless steel which is our everyday cutlery now it's a miracle it's like much better than silver we should do it

the other way around should eat silver every day and have stainless steel for a special christmas time i love the idea that canteen of cutlery where you just go uh can't oh you must be upper middle class no i was on sale of the century in a canteen of cutlery and these matching his name watches. I was able to take part in one of these experiments where you would take food from different metal cutlery. So I'd done this directly and it's 100% true. And actually

the lady involved said that the best thing you could eat, the finest thing you could eat was fresh mango off a solid gold spoon. And then she produced some fresh mango off a solid gold spoon and then she produced some fresh mango and a solid gold spoon and and she was right it was very good so obviously I'm spoilt for everything else now and um you know if anyone out there could just take pity on me in these very difficult and challenging times and send me a full a full cutlery set of solid gold cutlery and a

lifetime supply of fresh mangoes I you know, it would at least sort of make this period of time pass a little easier for me. I can't wait to see that advert on television. Katie has to walk over five minutes every day to get to fresh mangoes and don't spoon. But it was quite amazing. And as you say, the pollution in your, the pollution of the taste of it from a silver spoon was quite extraordinary, actually, compared to the gold one and the stainless steel one. Grace, I wanted to ask you, actually, as a restaurant critic, you said you have this unfortunate job of having to taste food for every day. Wonderful food from the best places in London.

It's awful. What's the strangest thing you've been asked to taste in a restaurant? You know, the thing that you thought, that can't possibly be a sensible dish. The thing that actually caused, and I'm not even saying this, I don't mean this as a joke, it caused a real depression in me that lasted for about two, an existential angst, depression in me that lasted for about two, an existential angst, was a chef who had replicated a condom in spun sugar. And it was one of those dinners where he, at the beginning, says, I'm going to take you on a journey, and it feels like a threat. And then right at the end, and he called this pudding Sex on the Beach. And it was a sugar spun i don't think it was bogna it wasn't bogna um

anyway i'm not going to go into how graphic it looked but it was very very realistic and then the bill came and it was 600 pounds for two people and um and i paid it because i had to because i'm not really that fast at running anymore as I've got older. But that pudding pushed me to the edge and it did not taste delicious. If you go onto my Instagram, there's a picture of it, but please don't sue me. Can I just say, I'm not surprised you're aggrieved about this, because if I end up with the contents of a condom in my stomach,

I don't expect to have paid for dinner. Yes. Beautiful. I always take it. But that is, I mean, that, Harold, what Grace was describing there, again, that psychosomatic reaction, it's a bit like that thing where, you know, if something is made

in the shape of something we're meant to be revolted by, I know they've done those experiments where, for instance, making something like, you know, in the shape of dog poo. It doesn't matter how delicious that thing is. We are reacting also to the, you know, there is something primal there, which means you're not going to find that particular version of death by chocolate a delight. Yeah, but I'd like to begin by saying that science is not guilty for crimes like that. by saying that science is not guilty for crimes like that. This is guilt by association.

So science helps us understand, manipulate things, how to make things, how to break things down and build them up. What you actually do in the kitchen for your customers doesn't have anything to do with that. That's an artistic decision or a commercial decision or something. So I just want to dissociate science from condoms on the plate. But yeah, the experience of food isn't just the taste and smell and texture and so on. It's also our database of past experience and expectation. And if we look at something and it looks disgusting, then our initial response is going to be disgust. Even if it's put a spoonful in your mouth and it's sweet and it's aromatic and completely not what you're expecting, disgust has been part of the experience. Well, picking up on that.

There's just no way of getting around that harold you that wonderful phrase our database of past experience i mean in terms of in terms of smells um i suppose some smell we've pre-programmed clearly to be repelled by certain smell rotting rotting meat or something like that there are certain things that is clear that we don't enjoy that sensation but this wide range of other sensations that you've described, I suppose that there's an element of learning, an element, as you said, of memory and where you experience those things. So I wondered how much of our enjoyment of food is learned, if you like. It's cultural, it comes from our experience, and how much of it is

pre-programmed genetically? Well, it's a good and ongoing question, and I would say that the current generally accepted view is that our preferences in food and drink are pretty much completely a matter of learning. So we're born with an innate preference for sweetness and innate aversion to bitterness. And that's kind of it. And young children don't have strong preferences. They develop them at a certain point. But before they do, they're willing to put things in their mouths that none of us would. So they're learning on the job and just depends on what's around for them to

put in their mouths, what they see their parents putting in their mouths. All these things make a difference to our eventual tastes and preferences and so on. I was just going to say, I wish sometimes that I could override memories that I have about food because there are you know there are certain things chefs absolutely love bone marrow the modern chef right now it's very it's very fashionable to to cook it and to me every time I see that come through the door on MasterChef there's just a slight whiff of it that reminds me of dog food from when I was a child and it reminds me of a friend of my mother's spooning it out of a tin into the dog's bowl and putting it down you know as we were kind of six seven years old and it's very difficult because I really want to overlook

that and you have these wonderful chefs coming in and they go and I have taken the bone marrow and I have chopped it roughly and put it back in with a creme brulee inside. And I can just feel there's a real, like that, and it's not professional. So I really wish that there was a way. And I loved how you were saying about sweet is something that we like when we're young. And because I've even seen myself

in the last 15 years of eating as I've got older and more of a vintage, I do, I like bitter things. And I'm very proud of myself. I feel very grown up when I go, oh, look at me eating on beef like an adult. Because these things, you know, drinking a really dry martini does feel like an adult thing to do because it's, and I suppose the science is that you're kind of moving into your vintage years where you're a grown-up. So anyway, thank you for making me feel special.

That's all I'm saying. See, I'm surprised you don't, because the dog food thing, I always remember as a kid thinking it looked really delicious on the adverts. I never tried it. I was lucky, but you know for me too did you have pets as a kid though robin because i think i'm also with grace on this because it was my job to feed the

pets and and i had to i can even hear the sound of me spooning out with the special spoon we have the special dog food spoon and okay once it got onto the table and i couldn't go anywhere near it so um you know i think these associations are really deep. Did you use the gold spoon or the silver spoon? Another thing that amazes me about this is, and this comes back to your job, Grace, which is that you give the same food every day to a dog for its whole life and it's fine, happy, no problem.

Give that to a human and you feel like really you're having a hard time, right? Why is it that humans require so much variation in their diet well I have my boiled egg every day and I find it comforting and sometimes and when I'm going to sleep I think I look forward to my boiled egg in the morning even though every day I think oh it'd be nice I'll get up and have my coffee and have my boiled egg and also when I'm working very hard if I'm really in a kind of zone of working hard the only thing I can ever eat for lunch is a cheese sandwich I think because I have associated it perhaps with school and packed lunches or something like that but it's just I don't feel like I'm working properly if I have something other than a cheese sandwich when I'm really in a big work zone so it's odd, these sort of psychological associations.

But how it... What do you do with the boiled egg? It's a medium. It's medium boiled, Grace. And so that means it's still a little bit runny in the middle. And I have it on a slice of toast, ideally a sourdough toast, but I think we've all got a bit beyond sourdough now. So whatever, whatever.

We're at the point of lockdown where whatever bread is around is fine um and then i chop it onto a piece of butter toast and then i put salt on it and then i put a little sprinkling of dried chives oh yes runny condiment on the side would you dip that sometimes if i'm feeling like nostalgic i won't have the dried chives because as you say with the endive that basically signifies adulthood to me and obviously it's just a big dollop of ketchup if i want the full comforts yes you see i think we could get 45 minutes i could easily talk condiment goes with an egg it says so much about a person i thought i thought she were going to say tea i dip it into my tea that wouldn't work at all and person. I thought she was going to say tea. I dip it into my tea. That wouldn't work at all.

And the reason I thought that was because it's a nice segue onto the final section of the show, which is tea tasting. See, that's what I love. That could have been anything she said. I thought you said quantum cosmological implications, which is an easy segue. Hang on a minute. That's just cheating i'm just

trying to be professional late now we're 40 minutes in tea like go and be professional so uh harold we we decided that we would have a tasting which would we we started out actually discussing a tea tasting but we realized that because this takes 18 hours to record, the tea that we'd prepared would be cold. But perhaps you could talk us through a tasting of tea and also wine, because that would be easier. Well, so I have tea because it's early morning, my time, as we're talking. And I would love to talk about tea because this cup of tea was made with my own tea. So I live in San Francisco. I have tea bushes in my backyard and I have them because they're robust. They can actually live in harsh climates, even worse than San Francisco, but also because

I'm just fascinated by the alchemy of making tea, which has to do with the biology that I was trying to argue for early on. It's amazing. You have a little tea plant, you cut off the growing tip, the tender little leaves, and you kind of rub them between your fingers and they smell like green leaves, like cut grass or something like that. You put it down and go away for a couple of hours, come back, the leaves have wilted because they're not connected to the mother plant anymore, and these leaves now smell like flowers. And that has all to do with the reaction that the living leaves have to the fact that their life has been disturbed. They've been cut off, they're losing moisture, the cells are suffering damage, and so what they're doing is actually signaling to the rest

of the plant, or trying to, there's trouble. And so the other leaves should get ready and ramp up their defenses. Plants are, unlike animals, unable to move. They're stuck in one spot. So if a creature comes along like an insect or me to do damage to it, to take advantage of it, the plants will try to defend themselves through chemical warfare. That's really their only defense. And these wonderful aromas that develop naturally in the tea leaf once it's taken off comes from the combination of chemical defences and warning signals communicating to the rest of the plant and to nearby plants that trouble afoot. Someone needs to let the tea plants know that the combination of chemicals that they're giving off as a defence and a warning against predators is making a really delicious drink and perhaps the most ubiquitous and widely enjoyed drink in the world. So their defences are rubbish, aren't they? I mean, someone needs, like, they need to really look at that, to be honest.

Actually, no, actually, actually, no, because... LAUGHTER Exactly because they're so delicious. We actually grow, there are probably more tea plants on the planet than there would have been had we not discovered and taken advantage of them. So tea plants are doing-

Tea has sort of domesticated us. That's right. Wow. That's right. All right. I like it when PG Tips just starts to merge towards Day of the Triffids. It's just got a nice kind of... more jeopardy there. I wonder if Harold would agree that the taste flavour profile of tea,

which is massive, huge, thousands of flavour molecules, is equal to that of wine, and that it's kind of weird that there's a wine menu, but there's no tea menu in most restaurants because tea is arguably just as good a drink to drink with food. In fact, superior in many ways, because sometimes the alcohol gets in the way. There are restaurants with tea menus. I actually prefer wine, but it is possible. And the wonderful thing about tea is that you can do so many different things with those leaves. You know, it actually depends on how much you annoy the leaves, the different flavors that you can elicit from them.

So you can just cut them off and dry them, and then you have green tea. If you cut them off and then kind of rub them between your hands and let them sit for a little bit and then dry them, then you have oolong tea. And then if you really crush them before you dry them, you end up with black tea. And it's a tremendous range of flavors that you can get from this one single plant. Mark, I just wanted to ask you, Mark, because you did a show which was with Marcus Waring, which was basically science versus cooking pretty much wasn't it and who won in the end well he won he won i mean but i mean i i in my defense i'd say i mean that um that steak you know the deep fried steak uh he did rate that really highly actually uh which was i i took as an amazing compliment but his stuff was more flavorsome i definitely but i i noticed two things that he uses that i i i felt like they're either

they're chefs of magic ingredients and i was going to ask harold about this what he thought one is a huge amount of salt much more than i would you know reasonably put in any dish and the other was an enormous amount of butter i mean the mashed potato was 50 butter 50 potato i am not joking you i am not joking you it was delicious it was delicious that's why it's delicious but i mean it was hard to compete i felt with the butter and the salt every christmas when the restaurants close some some clothes for christmas through the christmas period to let the chefs and the, you know, have time off. And I often lose weight at Christmas, you know, because it's just through not being at restaurants and just eating my own food, I would never put, you would never put that amount of

butter and oil and salt into your own food, because there's a there's a self preservation. And I don't even mean that as a joke there's a self-preservation stopping you doing it and the reason why restaurants are delicious they're so sating and lovely and comforting and you you know when covid struck and they shut it it made people depressed is because we're being deprived of this of the butter it's butter please if you, if you do an entire show on butter, bring me back. We will. Next series, we'll do the butter show. As usual, we ask our

audience a question, and today we ask them, if you could make one food extinct, what would it be and why? And our first answer was, Conorato says the Scotch egg. Neither Scottish nor an egg. And possibly responsible for a new pandemic. I don't know whether I should read out

Dingo's. Dingo just said mum's meatloaf. I really hope Dingo's mum isn't listening. Carl MC says revenge as it's always served cold to me. I don't know whether to start on this. I haven't read it all but but Andy Brockhurst starts,

My mother-in-law... Can you do it properly? You are from the north. My mother-in-law, mate. It's a banana and hard-boiled egg curry. I still shudder at the experience. That is banana and hard-boiled egg curry. That is an interesting one. And as usual, by the way, Julia, just so you know,

Brian, we've always got one of these. Get rid of margarine because things can only get butter every single week well done for finding the d ream pun uh so thank you very much to our panel harold mcgee mark miodovnik grace dent and katie brand and uh next week we oh no it's your line, I'm so sorry Brian next week we're talking about reality does reality really exist Robin what he did was he took the throw to his own joke away

I wouldn't say it's a joke let's just call it a sentence with hope does reality really exist Robin well at the moment I'm hoping not in fact I'm hoping I'm a Boltz Let's just call it a sentence with hope. This... Does reality really exist, Robin? Well, at the moment, I'm hoping not. In fact, I'm hoping I'm a Boltzmann's brain at the end of the universe, but I'm also hoping that I get to eat mango from a gold spoon before I dissolve

into the void at the end of time. Goodbye. In the infinite monkey gate Without you traveling In the infinite monkey gate Till now, nice again. Hello, did you know that in a million years there'll be no more total solar eclipses because the moon is gradually moving away from the earth? Or that during China's Cultural Revolution people were arrested for bourgeois habits

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