To me a kitchen is just like a laboratory and cooking is just another experimental science
The University of Bristol’s Pete Barham
Pete Barham pictured in his kitchen, equiped with a vacuum pump, filtration equipment, a blow torch and some onions!
If you’ve ever watched a TV show with Heston Blumenthal in it, you’ll know that there’s a bit of trend in cooking at the moment to be very precise and scientific about food preparation. Some of the most popular and succesful restaurants around like Blumenthal’s Fat Duck near Reading and El Bulli (in Spain) are using serious scientific techniques to create textures and flavours of food which a conventional kitchen can’t match.
I want to illustrate this with an example, but first a brief detour into chemistry. If you cool a solution of something down, sometimes it will crystallise. The more slowly you cool it, then the bigger the crystals will get. That’s why mineral crystals in underground caverns often get so big: they are undisturbed and grow slowly for thousands of years.
Back to cooking, and making ice cream. Here, ideally you’d like the frozen creamy mixture to be smooth and luxurious. The key to that is getting small ice crystals, so the cream mixture should be cooled as quickly as possible. Conventional methods (like using a freezer) do OK, but a scientifically minded chef might use something really cold, like liquid nitrogen at -196 degrees. This freezes the cream so quickly that the crystals don’t have much time to grow at all, and the result is seriously smooth ice cream.
Although I always enjoy seeing liquid nitrogen on TV (and throwing it around in the lab is usually good fun too) I’ve always thought the new fashion of using it in the kitchen is a bit gimmicky. Pete Barham from The University of Bristol wants to put people like me right though. In a new and unusual paper , he sets out his arguments that cooking, or as he dubs it, molecular gastronomy, is an emerging science. He thinks all aspects of cooking, not just making ice cream, could be pushed to their logical conclusions, and if we were to do it more often we could make really amazing food.
So what other aspects of cooking can science be applied to? Well, any aspect eventually, Barham would hope. For the moment though, let’s take the process of roasting.
Barham and his multinational team of authors took some existing research about what happens to the sugars and proteins contained in meats when they get heated up and identified some of the molecules which are the basis of flavours notes like ‘roasted’ and ‘caramalised’ which are desirable in nicely done meat. Since there are tonnes of different substances in meats, these reaction pathways get complicated very quickly, but essentially they undergo something called the Malliard reaction, and then further simple transformations. You can click on the picture below to get an enlarged view of the chemistry and see what some of the molecules we get out look like. These are the ones which generate the flavours.
Some reactions which develop ‘roasted’ and ‘caramelised’ flavours. [Click the picture to enlarge it].
So how is this useful for cooks? Barham argues that instead of just cooking in what I a like to call a Yorkshire housewife manner, i.e. guessing all our ingredients and cooking times through long experience, we should test different cooking methods and times to see which produce the correct balance of the right flavour molecules. And we shouldn’t just taste the results, but use robust scientific methods to get an accurate picture of what molecules are really there.
Once we have that kind of information, we might even consider making these flavour molecules in a lab and adding them to food to compensate for not-quite-perfect cooking. In the future we could have chemical racks, rather than spice racks on the wall marked with names like ‘bis(2-methyl-3-furanyl) disulfide; BEEF BROTH’.
Many people would consider this ‘unnatural’ and somehow unhealthy. For example, when you drink a cheap fruit juice made from concentrate, we can often taste the ‘unnatural’ fruit flavourings in it, and that’s rubbish. But it’s mainly because the level of flavouring and sweetener is badly adjusted (probably to the taste of teenagers), not just because the flavouring itself is unnatural. What Barham is talking about is taking a scientific approach to additives; making sure that we use the right compounds; the same ones that are generated by the cooking process, to perfect our culinary creations.
I guess for the moment, this is probably the reserve of Blumenthal and co., who, incidentally, Barham has worked extensively with. But I think he hopes this paper will be the start of this more scientific approach to cooking being rolled out in more restaurants to begin with, not just ultra expensive concept places. And why not? If chefs really want their food to be perfect, this seems like the logical way to do it.
 P. Barham et al., Molecular gastronomy: A new emerging scientific discipline, Chem. Rev., in press (link).