 I am so delighted to welcome you to the first of the 2021 British Library food season sponsored by KitchenAid. My name is Polly Russell, and I'm the founder and the curator of the food season, working very closely with my friend and partner in crime, the season's guest director, Angela Clutton. This is the fourth year that we have run a food season at the British Library. And like the other years, we have an eclectic bunch of events, which will explore every aspect of food. This year, we're going to delve into the history of pies, new food media, exhibiting food, food writing, food and masculinity, food and class, and food and cheese and the politics of coffee. There's a lot going on. Please join us for other food season events and check out all about them on the British Library's website. There's a link at the bottom of this page. On the same page that you're viewing, you'll also find details about the wonderful food season competition that we're running with KitchenAid, where you can win a cordless KitchenAid appliance, a place on a virtual cooking course, and the wonderful pie room book by Callum Franklin. Just a little housekeeping before we get started. Please do use the menu on your screen to provide us with feedback about this event. We really like to hear from you. There's also a donate button. The British Library is a charity, and we rely in part on your support to help us do the work that we do. There's also a bookshop tab on the screen, so you can browse and buy books from our guests this evening. And you'll find social media links at the bottom of the page should you want to continue the conversation on other platforms. Please also, throughout the event, do post questions for Harold and Tara. They would love to hear from you. There'll be an opportunity where Harold will answer your questions. You can do that again at the bottom of your screen, so please do think about that as you're listening to them talk. Right. Now about this evening, I just could not be more pleased or more proud that the season's first event features the legendary Harold McGee coming to us all the way from his home in San Francisco, California, discussing his extraordinary new book, Nosedive, with the wonderful food writer Tara Wigley. I'm going to let Tara introduce Harold properly, but I just want to say a few words about Tara. Tara started out working and publishing before switching to food writing just over a decade ago. She trained at the Balli Mello Cookery School in Ireland and then worked with Yota Motolenghi testing recipes before taking the role of being a writing collaborator. Tara was involved with the creation of books, including plenty more and Nopi, The Cookbook Suite. She's the co-author with Yota Motolenghi of the Runaway Success Cookery Book, Simple. And so she's almost a daily presence in my family kitchen and probably in many of your kitchens too. Her culinary expertise and understanding of flavor make her the perfect person to talk to Harold about his work and his new book. Now, just before we hand over to Tara, there is going to be a very brief tribute to Harold from the one and only Heston Blumenthal, whose life work, as he will explain, was profoundly influenced by Harold and his first book on food and cookery. So I'm handing momentarily over to Heston and then Tara's going to take over. Thanks so much. Enjoy this evening. Hello, British Library food season. I am very honored, chuffed and excited, to introduce my great friend and somebody that has really changed my life, both professionally and personally and preciously is still very much in it, like a valuable jewel, Harold McGee. If I could sum up the impact that Harold and his book had on my, not only my career, my life, the way I view the world, including very, very importantly myself, it's question everything, the importance of questioning. Thanks to that approach, I've discovered so much more about myself and in turn so much more about the planet and the universe and the sensorial world around me. I don't know how different my approach to food, my life in food, because it's very important for me cooking and eating. I don't know what direction it would have taken if I had not have fallen down, this is going to sound really dodgy, but Harold McGee's rabbit hole. The chances are, the chances are it would have been quite different. I might have found something else that would have triggered the importance of questions as opposed to answers. But because it was over, it challenged something so set in chef's bloods that you have to brown meat to keep in juices. It's something so obvious and so simple. The example of it was, oh my word, if this isn't correct, how many other things in classical and modern classical cooking also are not correct? Or maybe they were correct, but the ovens have changed or the pots and pans have changed or the ingredients have changed. Who knows? So it was the magic if we, it's so profound for me, this discovery. There's many important great things about this book. It is like on food and cooking, it is a weighty, it's a weighty tone. If you just walked to your local post office, there'll be smell of tarmac. There might be smell of freshly cut grass. There might be smell of rubber from the wheels of a car. There might be someone's perfume. That's a really complex world that can trigger all sorts of memories and emotions. All we need to do is become aware. And I think this book is a magnificent tool for anyone, whether they're interested in cooking or not, but the power and the complexity of smell, it is our world around us. I love that intro from Heston and love the idea of us all going down Harold McGee's rabbit hole. So Harold McGee needs a little introduction from me, but I'll just give you a little bit of background. He studied at Coltec in Yale. And since 1980, he has been writing about the science of food and cooking. He's the author as Heston was saying of the epic, inspiring, comprehensive and award-winning on food and cooking, the science and law of the kitchen, which made us all, as Heston said, question everything. And Harold often talks about paying attention and this idea of questioning everything and paying attention is just, it seems so basic, but it's so revolutionary when you start sniffing and smelling. He's a visiting lecturer at Harvard University's course from Oates cuisine to soft matter science, former columnist for the New York Times. He's been named food writer of the year by Bon Appetit magazine and in the Time 100 and annual list of the world's most influential people. He is, I'm sure, a very smart guy who is very skilled at giving smart answers to often silly questions a lot of us have about quotidian life. One of the amazing things I think about on food and cooking is that it was written without the aid of Google or Google Scholar. And I just wanna take the chance before we start Harold to say on behalf of all of us, thank you for being our Google, because just as we can't imagine what we do before Google, none of us can imagine what we did before Harold McGee and your Bibles that you give us. So thank you and looking forward to chatting. And as Polly says, if you've got any questions, pop them down and then we'll save them up for the end and we can all find out why we smells of asparagus or horrible after we eat asparagus and all such other things, other questions that we have. But on to Nose Dive. So I love the fact that Harold, you spent 10 years researching and writing a book that is 700 pages long, that has a time span of 14 billion years, but you still felt compelled to invent one new word. You felt like there was room for one more. So I was hoping you might start us off with telling us what this word is and what it means and how it sort of encompasses your ambition for this book, Nose Dive. Well, thank you, thank you, thank you. Tara and Polly and Heston, boy, my heart is beating fast with all of those wonderful words. Thank you so much. It's a great pleasure to be here. And I couldn't do what I do without libraries, so it's just wonderful to be doing an event that in some way supports one of the great libraries of the world. Anyhow, so yeah, when I started writing about smell, I kept finding myself saying the world of smells over and over again. How amazing is the world of smells? And let's explore this corner of the world of smells. I just felt that there should be a word that encompasses that idea, the world of smells. And so I have a brother-in-law who is a professor of classics. And I consulted with him on several possibilities, several coinings from Greek and Latin roots and so on. He vetoed most of them, but he allowed osmocosm, osmo from Greek root meaning smell, and chasm, of course, the cosmos. So I made us word osmocosm to describe the world of smells and that's what I tried to explore in the book. Yeah, and I mean, the ambition is extraordinary. The subtitle is a field guide to the world smells and this book is quite literally a field guide to every smell and you cover a lot of ground. We have the smells of earth, of animals, we have land plants, we have waters, we have fruit, we have humans, we have quite a lot of human excrement and we have, before we get to kind of food and wine, but the initial spark for the book 10 years ago did come down to a certain meal with a certain chef and your experience eating one particular type of food. So I was wondering if you could tell us a bit about this spark that took place 10 years ago? Yeah, and it's wonderful that Heston is kind of with us this evening because back in 2004, when I finished the revision of on food and cooking, I lifted my head from my desk and realized that the world of food had really changed a lot in the last few years that I'd been writing. And I talked with Heston about this and he said, you know, you really need to come over here and visit some of these places that are doing interesting things. So I took up his invitation and he and I went around to a variety of places in Spain and the UK and so on. Exploring restaurants that were really pushing the idea of novelty, of making a really memorable meal out of surprising you so that you would really remember that moment. And it was fascinating, but the last meal I had was at Fergus Henderson's Restaurant St. John. It happened to be the very beginning of grouse season and I'd never had a grouse before so I ordered grouse for lunch. And very, very traditional meal, you know, it was just roasted with a tuft of watercress coming out of its behind. And it just blew me away in a way that none of the novel meals that I'd had at the avant-garde restaurants had done. And it did so powerfully that for a couple of minutes I couldn't, I could barely speak. I was sitting chatting with other people and I just had to stop and pay attention to what was going on in my mouth. And that the power that my senses had over my mind at that moment really got me to thinking about the nature of flavor, how it is that that kind of power is exerted and what could it possibly be in this cooked bird that could affect me so strongly. And so that started me down, I guess, my own rabbit hole of trying to figure out what it was about flavor that could be so interesting and so powerful. And it was so interesting to me that you had such a powerful response to it because a lot of us think that our relationship with food and the power of it is tied up with memory. And the fact that you'd never had this grasp before meant that you had no memory to draw on. And then that sort of, it was interesting because we think of it as being so subjective and you, I think, made the wise decision not to go down the rabbit hole that would have been an entire warren of kind of the subjective relationship of food and memory and you would have had to have a kind of 12 volume book. And then that got you onto the firmer ground of your interest in flavor echoes and the mystery of why certain unrelated foods mirror one another on the palate. And I wonder if you could tell us a bit about the flavor echoes and why this is of such a dress. And maybe if you have a kind of flavor echo yourself that you're particularly tickled by, I know that mine is the sort of, when I realized that my dog's paws smell like tortilla chips and I sort of found this confirmation in the book and I've always thought it was kind of popcorn or tortilla chips, but yeah, if you could talk a bit about these flavor echoes that'd be really interesting. Yeah, well, that's really what led me to the idea, led me from the idea of writing about flavor to the idea of writing about the smells of the world because initially I thought, okay, this was a powerful experience. I want to understand it better we now have begun to understand how the brain proves things, lot taste and smell. So I'll write a book about flavor. But then as I began to do that, I began to realize that some of the most interesting things about flavor are in fact, these echoes, these quifts of other things in the world in the foods that we eat that may be other foods or they may be something entirely inedible. Well-aged Parmesan cheese can smell like pineapple and so you have kind of half rotten cow's milk on the one hand and a ripe tropical fruit on the other. What do they have in common? Why do they have this kind of relationship? Or of course, wine tasters taste all kinds of things and wines, flowers are, they're not especially edible but they're kind of pleasant. But then sweaty saddles is another term for particular qualities in red wines and it's true that there is a kind of leathery aspect to some red wine. So it was those kinds of correspondences that really led me to realize that in order to understand flavor, I had to understand why these other things in the world have the qualities that they do. And that ended up shifting my focus altogether so that flavor is, you know, it's a portion of this book but only a portion. And I do delve into dog's paws to try to understand why it is that they have these qualities that really strike us. That when you asked your editor for an extension on the done. And maybe we should talk a bit about kind of what smell is and, you know, I was talking to my kids today about smell and it feels like, you know, it feels like taste, they can kind of list all the different tastes that we've got and that's something they understand but smell when you actually talk about it, it's kind of almost a bit of a neglected sense and yet it's our most direct sense and it's much more, maybe we ignore it because it's sort of so much more complex than taste but when I was giving my kids today some of the kind of statistics about the number of receptors or the number of possibilities, it was kind of mind blowing and it feels like it's a bit of a sort of undiscovered sense. Not undiscovered but people aren't kind of, it's taken kind of nose dive to blow my mind about smell and sort of how that's and why that's happened. Yeah. Well, it really is true that in western cultures smell has been devalued compared to sight and to hearing. So, you know, we can make art, visual art, we can make music with smells, we can make perfumes but, you know, that's been a relatively minor part of our culture, of our heritage. It's very different by the way in the east where incense and perfume have been taken much more seriously and continuously for thousands of years but it is the case that, you know, even though vision and hearing have their interest, I like to point out the fact that both of them are very indirect indications of what's going on around us. You know, their light is being reflected off of surfaces or pressure waves are coming through the air from an object that has moved but in the case of smell, we're actually detecting little bits of the actual things around us. The smells are molecules that are escaping from these material things and flying through the air and into our nose and momentarily becoming part of us as we actually detect them. And of course, the things of the world are many, many, many and so the smells of the world are many, many, many and we have enough receptors and the brain power to be able to distinguish thousands, maybe tens of thousands, maybe we actually really don't know the theoretical limit of the number of smells that we could possibly detect. So it is this very powerful connection that we have to the world around us that has been neglected but happily is becoming more prominent. I love the way you employ your readers throughout the book to become better smell explorers and I just love this idea of kind of scout leader, Harold McGee leading all these kind of smell explorers behind him and I definitely, I feel like I am smelling more and again, you know, this idea that it's actually volatile molecules of the things coming off into my nose was just something I'd never thought about. But just as the scope of your book changed a lot from where you started, the world in which it's published in 2020 is obviously very different from the one you imagined and I wondered whether you could talk about the impact of the entire world having had their nose literally barred from smells for a whole year. Whether you think there's going to be some kind of collective olfactory euphoria when we have our masks taken off, whether you think we might become better smellers or whether you know any more about the research that's going into people whose smell, it's not that they've stopped smelling it's they're still smelling but their brain is interpreting incorrectly and they're smelling kind of awful things like kind of burning plastic or something rather than food and I know there's a crowdfunding group called Absent which I've heard you talk about elsewhere I didn't know if you knew any more about that research. Yes, so when I started writing about smell 10 years ago I had no idea that smell would be so severely affected for so many people when my book actually saw the light of day and there are different aspects to this. One is that because it turns out that the loss of the sense of smell is a very early symptom of COVID infection and because sometimes that smell takes a long time to come back or is deranged so as you say you smell something that should smell either neutral or nice but in fact people with what's called perosmia smell terrible smells which are not actually there so the fact that this has become a kind of public health issue has meant that there is now much more attention being paid to the sense of smell in the medical and the scientific communities. It's unfortunate that it took this to kind of make that happen but I think in the long run it's going to be very helpful. It's one of the ways we understand how the body works is by investigating what is going on when it's not working so well and so I think eventually this is going to lead to a much greater understanding of our sense of smell and then yeah, when we have to wear masks then we're both blocking the smells in the world around us from reaching our nose and we're becoming way too acquainted with our own smells, the smell of our breath that's being trapped in the fabric and so I think for many people it really does because it is such a change, highlight the fact that this is an important part of our everyday life and also simply the relief, I certainly feel this all the time the relief of finally taking off your mask and then being able to breathe in the world around you I think just helps us appreciate the fact that fresh air is a wonderful thing. Yeah, I mean yeah, I was just saying before we came on air that we had a, me and my husband had a different meal on Friday night to the food we were normally eating and we got as a takeout from a restaurant and it just made us realise how sort of institutionalised we've become in just the flavours that we're sort of eating cooking at home the whole time but it's the same with smell not only are we sort of barred off from the volatile molecules going into our nose, we're not experiencing the world and going to different places so we all talk about becoming a bit institutionalised and you lost your sense of smell during the course of writing the book was that, do you mind me asking was that Covid related or was that separate? No, that happened maybe five years ago so in the midst of writing a book about smell I lost mine and that was scary and it took a couple of months to come back and I asked my friends in the olfactory community the moment I noticed coming down to make coffee one morning and realising that the coffee tasted bad and that was the bitterness and the astringency and they were still there but the aroma was gone I asked my friends how can I treat myself should I go see a doctor, when will it come back and they basically said there's nothing you can do about it we really don't know that much about it usually it comes back but sometimes it doesn't so just kind of hang on and hope for the best and it did take a couple of months and those were very unhappy months That's a happy ending a dramatic turn of events and Covid aside are there ways in which we can become better smellers is it something we can train ourselves to do in a blood house that we can train up or learn from breathing techniques of dogs is it something we can become better at doing and then leading to a heightened sense of pallet and appreciation of food Yeah it's pretty straightforward just smell more and pay attention to what you're smelling and it can be as simple as as Heston mentioned walking down the street and smelling the tarmac and smelling around here in my neighborhood when I'm out in the evening I can smell people cooking in their kitchens and I stop and try to figure out from my own experience what are those smells coming from is it a frying pan and what's in the frying pan that kind of thing it's very systematic about it and I think it can be rather than being a kind of self-imposed training session it can just be a lot of fun to take five bottles off of your spice rack for example and just reacquaint yourself one by one with those smells what I find is that usually my spice rack is full of bottles that have any smell because they're so old and so it's a reason to refresh them but you can also do things like if you happen to enjoy Indian food take down bottles that would go into a spice blend for a particular dish and then open a bottle of the blend that you've already made with those spices or go ahead and make them fresh and then notice how the composite is so different from the individual components but yet if you really work at it you can pick out the fenugreek you can pick out the cumin we tend to think of the smells of food and drink and things in general as just themselves they're all impression but in fact they're kind of like chords in music they're made up of all these different notes of these different molecules that have gone into them and by taking advantage of the wonderful collections that we have in our own kitchens we can begin to become more sensitive to those notes and to how they build to make chords and then carry that experience out into the world again that's sort of such a it seems so obvious when you say this I've never sort of questioned before I've just sort of thought that a lemon smells of a lemon and that there is a smell that is lemon or strawberry and vice versa and that sort of takes sort of reading a book to realise that that's just this nonsense it's chords, it's a bouquet as you say but so do you don't think we can learn something from dogs and the way they're smelling what's happening with their kind of frequent sniff sniff sniff sniff, is it that they have more smell receptors than us or are they just better at sort of, do they smell things more intensely or is it something about the quick smelling techniques, sort of sniffing in and out technique that we can learn from I just wanted to get sort of sniffing sniffing their keyboards as they're their dogs collectively well yeah so it turns out you know we all have this general sense that animals are much better smellers than we are dogs in particular because of you know blood hounds and following trails and that kind of thing but in recent years scientists have actually taken a look at that and asked the question how sensitive are other animals compared to us and detecting molecules and the answer is kind of about the same, mammals kind of have the same abilities, what matters is sort of the experience, the day to day development of that kind of muscle in our set of abilities so of course for dogs which are a few inches off the ground and aren't getting a lot of information through their eyes their world is mostly smell and so they're acutely sensitive to small variations in things and they're sniffing rapidly all the time because that's just the most important sense for them. We're a few feet above the ground it's not so important for us but we can take advantage of their example by sniffing frequently something that I learned actually from my son is that who I guess just kind of figured it out on his own that if you're savoring a glass of wine or something like that you can get very different aspects of it by starting far away from the glass and then sniffing quickly and getting closer and closer and closer to it you get different aspects of the wines aroma at different distances from the edge of the glass so there are lots of different ways to do that just to get more information into our noses and into our brains so that we perceive more of what's actually going on around us. I'm going to start with Angela who is saying how if it's all do our other senses impact upon our sense of smell so again I wonder if dogs, if they're just all about the smell in the food they're sort of very good at that but whether it means that other senses they're not playing into it so much but we were designed by evolution not just to smell things but to perceive the world around us and as a kind of overall unified perception to know whether things are okay or not okay whether to change course or keep going the way we're going and so it's actually a kind of unnatural abstraction for us to focus just on smell and divorce it from taste or try to ignore what our eyes are telling us in judging foods wines, cheeses, olive oils things like that oftentimes the competition will ask you to do these things blindfolded so that your other senses don't interfere with your sense of taste and smell and your judgment but that's so crazy because it takes the experience of taste and smell and isolates it in a way that has nothing to do with our everyday experience of these things so they all do play but it's just never appealed to me on all levels and I also find it really discombobulating it's like if you're trying to watch a movie and then you're eating at the same time I just found it very odd not to be able to see what I'm eating and so it just shows how it's all linked fascinating and we said before that Covid has given us a big reason to all but certainly we all talk about more but it's also a big business I read about scented candles business something like netting 4 billion by 2024 and I wondered whether you had any predictions about how smell will be used by home comfort or tech or entertainment and that smell will be part of our 4D experience if we're watching television or in the cinema or do you think there's sort of new frontiers that Heston and the rest of the world are going to take us to with smell well back in the 1970s before I even started writing about food I remember going to a movie by an American director John Waters the movie was called Polly Esther and it came with a scratch and sniff card and so at certain points in the movie you were meant to smell what you were seeing on the screen and I just found that scratch and sniff card a couple of months ago in my boxes of various things and they're still there so it's been something that people have tried to do for a long time to sort of add the sense of smell to these other experiences that we can be entertained by or enjoy there have been smell operas and things like that they have generally not been terribly successful dealing with light waves or sound waves that's one thing but actually dealing with little bits of matter that come into your nose and then they have to be kind of dissipated before you can enjoy the next one it's just a very different kind of medium that said there's a lot of interest these days in digitizing smell in finding some way of sending a signal through the air to somebody's computer which might have a little USB unit attached to it which would respond and release a set of molecules that would imitate the smell that was at the other end of the system again not a lot of success so far but people are really interested in doing it and the research is turning out to be very interesting because it's telling us about how you can how you can imitate the smell of an actual thing in the world with just a couple of molecules that you've figured out using machine learning for example can trigger your or trick your receptors into thinking that it's that same molecule so interesting things coming interesting I got some sort of business cards last year where it was it had sort of things like beer and bread and eggs and you could it was a scratch and sniff thing again and it was meant to help tell you whether something was going off so rather than just looking at the expiry date you could tell by the smell and I had it on the fridge for a while and it was quite novel and that was just interesting to think that could help against food waste rather than people kind of blindly following dates but all this talk of scratch and sniff reminds me that I must ask when the scratch and sniff version of nosedive is coming out they were obviously all very much looking forward to we had a great big lemon simple on the cover and I was lobbying to get that scratch and sniff but the publisher didn't go for it there's been a lot of questions about something that I wanted to ask about a little bit earlier about there's one about why do spices release smells when they get hot and another question about how does the temperature the ambient or material being smell-tasted affect our ability to identify different smells and it reminds me that I wanted you to expand on the example you give of sugar in the book and what happens to sugar when it's heated is just a really a way of people like me who are not scientifically minded to understand what is happening when heat is applied and the volatile molecules and how such complexity can come from something so initially simple because sugar doesn't have a smell when it's not about itself so writing this book about smell in general really enriched my understanding of cooking in a way that I hadn't anticipated because if you think about it we mostly eat plant and animal materials they're made up of very large molecules that are too large actually to fly through the air and into our nose so they don't have any aroma to speak of the aromas that they develop in cooking develop when we use heat the energy in heat to break apart those large molecules into smaller fragments that are small enough to fly through the air and into our nose and to me the primo example of that kind of alchemy is caramel so you start with one single molecule sucrose which has no aroma whatsoever it doesn't have any other taste and it's white and it's a crystal a solid and you simply add an energy in the form of heat and let it go for a few minutes and first the solid melts and now you have a liquid and then the liquid begins to develop an aroma and then it begins to develop a color and then you end up after a few minutes with your kitchen just filled with this irresistible aroma of caramel and if you taste it, not only do you enjoy that aroma but the flavor now includes not just sweetness but sourness acids have been created, bitterness savoriness so you start with one molecule and then you have about hundreds and hundreds of different molecules all of which end up giving us this overall impression and that kind of thing happens even when you're simply warming something up it doesn't take much energy whatsoever to begin to change the materials that we're enjoying and that's the key to cooking is taking the materials that nature gives us I think the smell of onions cooking saves a lot of people who are running late for the cooking of their meal because you just put the onions on in the pan and everyone in the house thinks that the meal is just around the corner even though you've just kind of three minutes in and again it feels like a form of alchemy this onion which is so un-sexy by itself with the combination of heat and fat in the pan it's just filling the whole house with this incredibly homely aroma it's sort of daily magic James Savage is asking a couple of questions about this rabbit hole that you chose not to go down to in terms of memory and the subjective nature of a smell she said what is it about taste and smell that triggers memory she asks why do we like the unacceptable smells from our own body and not those coming from others so I didn't know if you wanted to talk about what you don't talk about in the book which is this kind of massive subjective of rabbit hole of the subjective nature of it all the Madeleine moments Yes so when I decided to write about smell then I had to think about the fact that there are two aspects to it there are the molecules in the world that are emitted from things around us and that fly into our nose and trigger perception and then there's the process of perception the moment that it hits our receptors and then gets into our brain and that's where the sensation of smell or a flavor if it's a food that I could handle both in a single book You had us to say no So I set aside the issue of what happens after the molecule hits our receptors but that is another terrifically fascinating aspect of the subject and in fact it's just so difficult but also really intriguing to think about because we only know smells by our experience of them you know if we've never encountered that molecule before then it doesn't have any meaning for us so what we end up doing is associating smells with the things that they appear to be coming from and we usually give the smell a name the name that belongs to the thing that it's coming from so a lemony smell is lemony because it comes from lemons and the smell of dog paws comes from dog paws and reminds us of the smell that comes from corn chips we don't have a kind of abstract vocabulary for some other things and that vocabulary depends so much on an individual's experience I give the example in the book of the Brazilian chef Alex Atala making it possible for some of us in the west and the north to taste ants that are eaten in the Amazon but us tastes like ginger and lemongrass because they share those molecules but Alex made the point that when he brought ginger and lemongrass to the Amazon to the Amazonians those things smelled like ants so exactly the same molecules but completely different set of references so of course that is critical and without memory we can't draw on past experience and so the connection between the experience of smell and memory is very very tight and there's also a kind of anatomical aspect to this which is that the sense of smell is wired very directly associated with emotion and with feelings of pleasure and disgust which makes perfect sense because one of the functions of smell is to warn us when we're about to encounter something that's not good for us and so we have that kind of immediate connection and then the kind of more more general experiential connection with memory all of these things are in the pot when we smell something and teasing out which elements are most important depends so much on that particular occasion and the person and so on and so on people talk about the smell of fear does fear have a smell? it so fear causes people to perspire more strongly than they would be otherwise and perspiration carries chemical signals that include what we think of as body odors and generally speaking try to get rid of and so if someone is fearful and they don't have the chance to shower immediately then yes the trace of that experience will be with them for a while there's another question just talking about how different smell is for individuals there's a question does everything smell the same no matter where in the world it's at it was interesting not only did you feel the need to invent a new word it makes a 700 page book but you also then wanted to rename Petricor with another word so I wondered if you could tell us about that and what Petricor is for those who don't know and how it means that the world does smell differently everywhere and what you've renamed it well yeah so fresh air is wonderful but it smells different depending on where you are on the planet and that really intrigued me why it is that the air out in the middle of nowhere has the smell it does and it turns out that decades ago scientists in Australia had investigated why it is that the earth develops a particularly noticeable smell when it rains after a long dry period and they studied in particular the smells the volatile molecules that come off of rocks that have been dry for a long period and because the smell comes off of rocks they named the smell Petricor from a root meaning rock or stone and then icor which is the circulating fluid in the gods so kind of like blood but immaterial and so this was the in a way the essence of the smell of rocks but it turns out that the smell doesn't really come from the rocks themselves it comes from the stuff in the air that ends up sticking to the surface of the rocks and then when rain comes along the rain dislodges that collection of molecules that has accumulated and releases them into the air and that's when we're able to smell them so I think that rather than calling that smell the smell of the rocks Petricor it should actually be thought of as the smell of that particular part of the world and it's not just the vegetation it's industry if there's industry it's whatever is going on and so I chose to come up with the term Gaia icor so it's the smell of all the living processes living and dead processes that are occurring in that particular place in the world over the course of those that period of time epic so yeah 14 billion years the galaxy, the world of Gaia icor there's also a question from Samantha about whether you researched the possible experience of smell of the unborn baby in the womb whether you managed to go on that kind of space odyssey well I personally did not but there are studies that have shown that infants whose mother is exposed to particular smells will respond when the infant is born the infant will respond to those smells in a way that the infant of a mother who was not exposed to that smell would that is to say the mother's exposure to smells influences the baby's experience in the womb and again kind of makes sense because you know you're the mother is preparing the child not only to be able to survive in the world but giving that infant its first tastes of the world its first sense of the world and so many of the smells that characterize the foods that the mother eats end up in her bloodstream and in the amniotic fluid and in her milk and so an infant is getting all kinds of information kind of a preview of the smell world by virtue of its life inside the mother and then being nursed by the mother I have time I think we've got time for a couple more questions Helen is asking is fascinated by the cultural differences in the experiences smelling so for example the durian fruit which south east Asian smellers this is sweet in custody whereas many westerners describe it as disgusting is this conditioning or is there something else going on so again a big kind of subjective question but the actual the actual experiences you know is it language is it context is it association all of the above but I can speak directly to the experience of durian because I went on an expedition to Singapore to experience it to understand what's going on with exactly this kind of dichotomy people who love it and people who are disgusted by it and I experienced both for someone who is not used to it it's a it's a weird combination of sulfury oniony compounds oniony kind of at best and maybe a little more disgusting at worst a combination of those molecules and the molecules that are typical of fruits including things like strawberries so the strange thing I think for people from the west who have never experienced before is this combination of sulfurousness and fruitiness and it just comes off as being strange but the more time you spent with it and the more I thought about it the more I could appreciate that we could do the same kind of thing here and it would be unusual but it wouldn't be disgusting so it really is a matter of the frame of mind in which you experience something and I think the advantage of paying attention to smells and sort of interrogating our experiences of them is that they can broaden our palate broaden our appreciation for things in a way it wouldn't be possible to simply take one sniff and you're disgusted and you never smell it again that's all you're left with but in the southeast Asia the durian is considered the king of fruits and so you're missing out on something if you don't at least appreciate a little bit of that royalty yeah it's fascinating and the context is the kind of the French smelly cheese and the kind of the teenage smelly smell very similar and yet one is kind of delighted and one is not maybe we can end our questions on what your favourite flavour echo is I've heard you talk about a lot about the argo words of the smelling of the incense but do you have a food flavour echo that you're particularly tickled by that's a tough one because of course the more that I worked on this book the more of those echoes I often would first read about and then go to the foods themselves and notice for the first time so it's an example of experience at second hand the molecules tell you that there is this connection and then you go and actually experience the foods and sure enough it's there one of the things that that I really love is the so I love coffee that's how I first discovered that I'd lost my sense of smell and one of the things I love about in particular Ethiopian coffees is the note of blueberry that you can often have in them and to me that's just mind boggling because you have again this seed that's been roasted to 400 degrees Fahrenheit or something like that very high temperature, something that a blueberry would never survive and then you brew liquid from it and you end up with the aroma of a fruit a northern fruit wonderful so we've had less than an hour to talk about a book that you spent 10 years writing which feels kind of mad but I know that a lot of people would be desperate to hear what your next project is so I'm going to go back to food and cooking or moving on to a site or what's the next 10 years well whatever it is I hope it's not going to be 10 years worth I'm actually recuperating from this last 10 years for eight of those 10 years I was late to my publisher I think I'm going to come back to food though because that's where I got started and I now have a perspective on it that I really didn't have before so I want to explore that I think a little Harold McGee novella would get down very well but your publishers must be equally excited and nervous about what potential you could do in the world of food now that you've got Google available to you so we look forward to Harold McGee on food plus Google so I think sadly our time is coming to an end but it's just been so interesting and I just implore everyone to do a deep dive into nosedive and Harold encourages us or reassures us that we don't need to read this the 700 page cover to cover it's a field guide it's not necessarily one you put in your pocket but it's one you're walking around a field but it's one you can return to when you're out like Heston walking to the post office and smelling the wheels of a car you can then come back to this book and dip into it so although it's a big book it's actually incredibly light which is a mystery to me but I'm very grateful for Harold's reassurance that this is one that we kind of dip into and just keep us smelling and paying attention and becoming better smell explorers and as Heston said to question and smell and hopefully taste everything so thank you so much Harold thank you Tara it's been a great great pleasure thank you both so much what a wonderful evening and discussion now is more I'm sure that everybody else could as well there are so many questions coming in like Tara says this book is completely riveting everyone needs to deep dive into it if you are curious about dogs paws smelling of tortillas if you're curious about Ethiopian coffee and blueberries the book is just packed full of wonderful explorations like that and it does make you see the world differently so this was a wonderful introduction and explanation to this book and this work and the world of smell so thank you so much Harold and Tara for just getting the 2021 food season off to the most wonderful start and thank you also to our audience please do check into the British Library website for upcoming events don't miss for example this Friday what is likely to be a very lively discussion between the Michelin star chef Tom carriage and the writer of dudes diets and diners Emily about masculinity and food or indeed the conversation about French cooking and restaurants with the writers Jonathan Meads and Bill Burford and the restaurant critic Trace and Floyd on the 21st of April and there is much much more please again do send us comments we'd really love to hear from you the good the bad and the ugly remember that there is a donate button if you feel so inclined to support our work and finally thank you again to our speakers this evening and to KitchenAid for sponsoring the food season what a great stars good night