Paul Merrett: Hi, I'm Paul Merrett, chef and presenter of the BBC Open University TV series Ever Wondered about Food? and it's a programme that explores the absolutely essential link that science has with food. And I'm sat with David Shuker who's the man behind the science right the way through the series. Hello, David.
David Shuker: Hi, Paul.
Paul Merrett: David, it seems to me that, ever since the first pot hit the open fire, science and food have been absolutely, intrinsically linked. It's only now that we're really going through a little renaissance, an understanding, and trying to understand how science actually affects our cookery. Has there ever been a point in the last few years where you've suddenly thought, "right, I need to ditch the lab coat and all the test tubes, I need to stick on a chef's hat and do some cooking?" Was that joy always there with you?
David Shuker: Actually, you're absolutely right; there have been moments where I've thought that the only difference between what I do in the lab, as a chemist, and what I do in the kitchen is that, in the lab, when I make something I tend not to eat it. Okay? That's what I tell all my students. The great joy of being in the kitchen is, I'm doing chemistry but I can eat it. And it's interesting that you pose the question or that you said the things the way you did about the fact that we're trying to think about how science and cooking are related.
Historically, I think, it's interesting to think that science came out of human activities. Science is not something we plucked out of the, sort of, the atmosphere. And interestingly a lot of the processes that we use in cooking - as you said, heating things. We do all sorts of things - but actually if you think about it, are things we do in the kitchen with pots and pans that we do in the lab but with glassware.
And I personally don't see the sort of big difference between them. In fact, I've often thought that what I'd like to do is bring a whole load of my chemistry equipment out of the lab and use it in the kitchen. I mean we've got some wonderful kit, for example, for magnetic stirrers that stir a sauce. I could do great things with that, and I know Heston, for example, uses some glassware to stop some of the volatile things going out of his sauces.
Paul Merrett: Yes, out of his stocks.
David Shuker: …out of the stocks, and that's great science; but actually it's great cooking. And I think what we're doing is perhaps using the words "science" and "cooking" as if they were kind of separate universes; where in fact I think it's all mixed up together. So I think in the sense that… the same way that modern chemistry came out of alchemy, well a lot of domestic science came out of cooking, I mean that's the way it goes.
We might understand it a bit better now in terms of molecules and all the rest of it but of course you might argue that all the great cooks and chefs down the ages have intuitively known about the science. They've known about heat transfer; they've known about the importance of acidity from one thing and sweetness from another; they've known about how to form a stable emulsion; even without knowing the words or knowing the processes, it doesn't really matter because the end effect is the same.
Paul Merrett: My granny was a great cook, and I reckon she'd had watched Ever Wondered About Food? with a kind of a strange look on her face - I'm not sure she'd really wondered that much about her food, but she was a great cook, so she was obviously understanding the science without actually bringing it to the forefront of her mind and pondering the whys. And what I'm really interested in nowadays is, when you see a recipe it's the sort of unwritten line in between the two directions, so a recipe will tell you to do something but then it won't tell you why you're doing it, and if Ever Wondering About Food? does one thing, I hope it explains a few "whys" for people; I hope it answers a few questions that cooking food raises for them. And I'm also beginning to wonder - if you're an amateur cook then perhaps I can call myself an amateur scientist?
David Shuker: I would have no problem with that at all. In fact I think anybody that thinks about anything deserves the phrase 'scientist' because it implies…
Paul Merrett: Excellent, well I'm going to do it from now on.
David Shuker: So don't use the word 'amateur', not in a pejorative sense, I would prefer the word amateur in the French sense, amateur - that is somebody who loves it, so that's fine by me.
Paul Merrett: I shall do that. Now we've just made a programme about rice, which I have to say is one of my favourite programmes because rice is such an important food source the world over; it's one of the staples of the world. And the part of the world that I was born in - I was born in East Africa on a little island called Zanzibar - rice was the potato and bread of that island; there was no potato, there was no bread, you had rice with everything.
And it's a really, really interesting thing to cook because so many rice growing countries have developed their own way of cooking their own rice dishes, and I'm thinking of paella from Spain or risottos, or byrianis from India, and I just wondered whether you had used the different rices perhaps to - if you'll excuse the pun - go against the grain; if you've tried to use different rices for things that they weren't intended for?
David Shuker: Well yes, I mean… I suppose the classic one is if you reach for your rice out of the pantry and you pull out the short grain rice which we would tend to use for making a rice pudding and to try and make a dish which really should use a long grain rice, a basmati rice, then you'll probably notice the difference straightaway, so not all rices are the same by any means. And, of course, a lot of that difference has got to do with the way that, perhaps, different strains of rice have different levels of starch or slightly different structures, but then it's how you cook them afterwards.
And of course the big difference between the way you cook paella and the way you cook risotto and the way that you boil another rice makes all the difference in the world to whether that rice retains its sort of grainy integrity, as opposed to releasing a lot of the starch, and therefore sort of thickening the sauce around it, and a lot of these things were covered in the programmes. But, interestingly, what underpins that is the different science about what goes on when you cook rice in a different way.
And therefore that's what makes rice a very versatile ingredient of course because, in a sense, you can do different things with rice and end up with different textures and different flavours - that makes it a great ingredient. And it grows in many different climates around the world; I mean I guess many people would be surprised to hear that Italy is a great rice growing country. I mean, if you drive around the roads in Northern Italy, where it's nice and flat, you'll see these fields full of water, and I thought it was flooding, and they said "No, no, it's paddy fields."
Paul Merrett: Paddy fields, yes, it's amazing isn't it?
David Shuker: Which is great.
Paul Merrett: Yes. I worked on Sri Lanka, on the island of Sri Lanka for a couple of years and out there paddy fields were… every other field was a paddy field, and there was a huge amount of rice. And it is a very, very starchy ingredient that you sort of need a little bit of… practice makes perfect, I think with rice - the amount of water you add is very important, and then the way you apply the heat to the pan is very important, you know, whether it is fierce in the case of a byriani, fierce heat that's then turned off and you almost allow it to steam in the steam that you've created in the pan, or with risottos, in the kitchen we describe it to young chefs as braising that, because you're using quite a simmering temperature, you're stirring a lot and you're keeping the whole thing moving. And a risotto really is: you have to be over a pan to make a good risotto; you can't walk away from it.
So this relationship between the starch and the cook seems to be quite important when you're cooking rice - the understanding.
David Shuker: …the understanding. And of course it's obviously part of the way that chefs are trained, and a lot of it is not necessarily explained in the way that you say, "Well it's, you're releasing this starch in a certain way," but the point is that's actually what's going on, it's underpinning it, but obviously as part of chef's training you learn to cook in different ways. But it is interesting that it's all about the heat transfer, it's the way whether you stir the rice, and how frequently you stir it, and the way the heat's applied. It's all very subtle but if one were to look at it very carefully you could interpret it in terms of pure science; but in order to make that an interesting dish, of course, you have to combine the pure science with the art of knowing, mixing it with the certain flavours and all the rest of it.
Paul Merrett: I think, from a cook's point of view, that's one of the other interesting things about rice is that it's a great vehicle for flavours. It does have a very distinctive flavour itself but you'd rarely eat a bowl of rice. I mean there are hundreds of, millions of people in the world that do just eat rice, but from a cook's point of view you would always harness other flavours to rice - it seems to carry flavours very well; sweet flavours or savoury.
David Shuker: That's right. It is interesting that, isn't it? Because it's very difficult to think of another food ingredient which could be just as easily part of a pudding, as in a rice pudding, and be a part of a very savoury dish. And I suppose it is an interesting thing to reflect on, isn't it, that it has a distinctive flavour but it's not a very strong flavour, it's more a flavour and a texture, onto which you can build other things.
Paul Merrett: I mean texture's the word there, I would definitely agree. But it just seems to be, it's filling and that's why people are involving rice and starch in their diet, but I think potato is probably the British equivalent of rice, but I don't think it carries flavours as well as rice.
David Shuker: Well it's all probably to do with the physical structure of it, when you think the small grains of rice as opposed to the large mass of potato. I think there's another interesting aspect about rice, and which probably led to it being used so widely around the world, and that is, it's relatively easy to store. Once you've harvested it and got the grains, you can store it for quite a long time, and therefore it means that, even though it's grown seasonally, it can be eaten throughout the year.
Paul Merrett: Unlike potato.
David Shuker: Unlike potato which is very dependent, it can be stored, and I think, again, some of these things, my mother tells me that when she lived on a farm, vegetables like carrots and potatoes and all the rest of it could be stored in sort of great piles, as long as you keep the light out and all the rest of it, and you keep the humidity right, you can store it - well we've lost the art to do that. Rice is actually much easier to store. There are problems if you store it and you've got a bit of dampness around, you can get fungus growing on it and all the rest of it, but I mean that's going to be a problem with most foods.
Paul Merrett: When you're learning, you know, all about your health and the hygiene in the kitchen, rice does come in for close attention on that front. You were taught very carefully that it's fine to use left over rice but you need to cool it quickly, you need to cover it, get it in the fridge, take it out and heat it to the right temperature; because it does carry some pretty dangerous organisms within itself anyway - it comes with, is it bacillus cereus that you find in rice?
David Shuker: Well I'm not sure of the exact species but it is interesting of course and to reflect on why that should be - and that is of course that the reason why rice is such good food for us, it's full of good nutrients. Now once you've cooked the rice and released some of that starch and all the rest of it, whether or not those organisms are in there - or even as you cook in the sort of open air they can sort of land on it, then obviously if it's good for us it'll be good for them to grow as well, so that's a problem with many foods.
But I'm aware that with rice it's a particular problem; yes you have to be careful.
Paul Merrett: What are the particular health benefits of rice? It feels, I mean if you look at white rice, it feels like a very clean, it's very, very white, it's very clean, it almost looks like it needs to be a bit more sort of wholesome-looking to be good for you, I often think.
David Shuker: That's always a problem isn't it? I mean that's one of the things about the sort of things we call the various white deaths: the sugar, the refined flour or white rice. Well, of course, I don't know for sure if there's a big difference between the contents of the wild rices. I mean I certainly know that one has to take a lot more care in cooking them because, unless you're careful, they can end up being quite mechanically difficult to eat, and I don't know too much about the different wild rices.
Paul Merrett: Well certainly the very thin black wild rice, I avoid it at all costs; you can't eat it, I don't think; it's awful stuff.
David Shuker: Yes, absolutely. And remember that, of course, like many of the vegetables that we eat in our staple foods, they originally started off life as a wild variety, and the main strains of rice that are grown are ones that have been developed through agriculture. But they derive from the wild varieties, and my guess is that the way this has worked is that, over the years we've selected through plant breeding varieties which have got properties which retain the benefit of the food, the wild variety, but at the same time they're easier to cook, they're easier to store, so that's what it is. So I think when we're looking at white rice, we're looking at something which has retained some of the advantage of its ancestry. So my guess is, I wouldn't come down too hard on it.
Paul Merrett: Have you tried brown rice?
David Shuker: I have actually.
Paul Merrett: Which of course is the rice with the husk left on; without the husk removed.
David Shuker: This would be something like the different wheat flowers, you know where they retain the fibre. Well, the advantage is of course you get the fibre and that, which is beneficial because that fibre is essentially a sort of polysaccharide which doesn't get broken down in the gut so it helps the sort of transit through the gut and everything like that. So there is a definite advantage of that, the sort of the whole grain type story.
Paul Merrett: My mum would say "a bit of roughage is very good for you, son," that's what she would say.
David Shuker: Absolutely. Rice is such a staple throughout the world, but there are people that eat rice where they don't have the other parts of their diet which would be beneficial. So one of the approaches has been, so "okay people are eating rice, is there any way that we can modify rice to carry with it additional health benefits?"
Paul Merrett: Is this sort of like putting omega-3 in egg yolks?
David Shuker: Yes, it's exactly the same thing.
Paul Merrett: It's harnessing something good that wasn't there before.
David Shuker: It's harnessing something good that wasn't there. The problem of course is if it's genetically modified food, because what you do is that you take rice and you insert into its genes a gene, in this case, for the production of retinol, which is a precursor to vitamin A. And so, in areas of the world where people eat rice but they don't get enough vitamin A and therefore go blind, one way to address the problem is, you could give them pills of vitamin A, right, or retinol - but there's all sorts of issues, such as…
Paul Merrett: …are they going to take them, for a start? Yes.
David Shuker: …are they going to take them? So why not just get it as part of their food? But because it's in the area of GM foods then it gets overlain with all the issues around that.
Paul Merrett: Well I've got a bit of a sort of a fag packet scientific theory here that everything we eat is genetically modified food. A cow is genetically modified food - you know, husbandry is all about genetically modifying animals, isn't it? And is there a real difference between… because I'm sure a lot of the more unusual fruits and vegetables we eat have been genetically modified, if only by Nature they've been genetically modified. What's the real difference between a scientist saying "we can make this rice more healthy" and Nature just allowing something to grow rather than something else and doing the genetic modification for us? Do you see what I mean?
David Shuker: I do see what you mean.
Paul Merrett: I often struggle to understand why people get so up in arms.
David Shuker: Well I mean, I suppose the biggest difference, you might say, is time. You're absolutely right, I mean when you think about well, for example, the husbandry that's led to the selection of various breeds of cattle, that's more to do with genetic selection; that is, you select animals that have got certain traits and you breed from them. That's a little bit different than saying "Okay, let's take this stock and put in some genetic material from quite often a completely foreign species," so you might, for example, take a gene from a bacteria and insert it into a plant or something like that.
I suppose the issue is the concern that genetic engineering is carried out on a timescale which is vastly more rapid than evolutionary time. And the question is, "Is that intrinsically similar to evolution but it's just going on faster?" or "Is it somehow it's a fundamentally different thing?" There is a fear that it's sufficiently different, i.e. that, if you transfer a gene from one species to another remote species, just like that, almost instantaneously, you haven't given, as it were, Nature time to deal with that and adapt to it, and it's all to do with adaptation. So the question is, "Are there unforeseen consequences of suddenly moving a gene from one species to another that we haven't really thought of, because you know the whole way in which Nature works?"
But, actually, I think on balance I'm with you on this. I think that, fundamentally, we're doing something that happens in evolution but in a different way and therefore that we shouldn't be overly concerned; however, people are concerned about it, and people's concerns are not something that can just be ignored. And I think if we're going to try and persuade people to eat food, for example, which is genetically modified, then we have to explain to them very clearly what that is and what the effect is. And that's a job that needs to be done.
In the case of golden rice, I think there's a very good argument for using rice as a vehicle to deliver something which is definitely beneficial, will prevent people from going blind. And we're not talking about a few people; we're talking about thousands, if not millions of people.
Paul Merrett: And it's simply because they don't get enough…
David Shuker: It's simply because they don't get enough vitamin A.
Paul Merrett: …vitamin A, yes. So I mean, on the face of it, that's got to be a good thing, and golden rice is already being grown, it's already…
David Shuker: It's already available. It's something which has been developed by a large, multinational company and it's being distributed in areas of the world where it would be beneficial.
Paul Merrett: Well, David, I don't think anything else can demonstrate the link between food and science in a more positive way than the story you've just told, and thanks very much for that. To find out more about the science of the food and to get any of the recipes that I've cooked on the show - and how about a bit more of me and David chewing the fat, please visit our website at open2.net. I'm Paul Merrett and I've been talking to David Shuker of the Open University. The Producer was Michael Brodbin. This is a BBC Worldwide Production for the Open University.