Science and cooking are natural bedfellows. Witness the plethora of books on Amazon explicating the basics of kitchen chemistry, should you harbor any doubts about that statement. Beyond those basics, food technology has often focused on ingenious delivery mechanisms, most notably packaging whipped cream under pressure in handy aerosol cans. In 1998, Time magazine listed Reddi-Wip as one of the 20th century's top consumer inventions.
These days, chefs are moving way beyond the usual run-of-the-mill concoctions and are making use of cutting-edge technology to create tasty treats. Leafing through the February 2006 issue of Discover, I was fascinated to learn that Homaro Cantu, renowned chef at Chicago's Moto Restaurant, uses a customized ink-jet printer filled with soy-based edible ink to create "cartoon sushi." The usual red snapper and mako fillings are wrapped in edible starch paper emblazoned with a motif of tiny maki rolls, adding an extra visual element of pleasure to the dining experience.
Edible inks aren't just reserved for haute cuisine. Gastrophiles would shudder in horror at the very notion of Pringle's Prints, in which each chip is imprinted with a fun trivia fact, but it's a true democratization of the technology. After all, far more people consume potato chips than could ever afford to dine at Moto. (On the "real science" front, New Scientist magazine reports that scientists recently used ink-jet printing techniques to "print" 3D tubes of living tissue, the first baby step towards the Holy Grail of tissue engineering: printing out entire organs, complete with their vast networks of arteries, capillaries and veins to keep all the organ tissue nourished.)
Cantu has a few other technological tricks up his sleeve. He uses liquid nitrogen to transform pureed heads of romaine lettuce into crystallized pearls for a very cool take -- about minus 273 degrees F, to be exact -- on the classic Caesar salad. He's been known to compress oranges in a tank filled with carbon dioxide, carbonating the fruit so that its juices bubble up like soda pop when squeezed. As for dessert, how does an edible balloon of yuzu (a Japanese fruit) strike your fancy? All it takes is a centrifuge -- basically a high-tech salad spinner, commonly used to separate blood proteins in scientific laboratories -- to spin the fruit juice while simultaneously chilling it with another dose of liquid nitrogen. The result is a thin, round, hollow shell made of frozen fruit juice. Cantu is also reportedly experimenting with ways to fill this tasty sphere with helium so it will float; how to cook beef with a high-powered laser; and how to use that self-same centrifuge to clarify thick meat stocks.
He's not the only world-class chef interested in the science and technology of food and cooking, and applying it to enhance the fine dining experience. One of London's most famous restaurants, The Fat Duck, now employs a biochemistry grad student in its development kitchen. So it's not surprising that one of the most intriguing dessert items on the menu is a cookie that fizzles in your mouth like champagne.
It's all part and parcel of the flourishing field known as molecular gastronomy, in which researchers study how the structure and taste of food changes with, say, the application of heat -- a process more commonly known as "cooking" to the average layperson. One of the founding fathers of the field is the late Hungarian-born Nicholas Kurti, a low-temperature physicist at Oxford University and unabashed gastronome who was the first to use a thermocouple to probe the internal temperature of a cheese souffle some 35 years ago. He famously lamented that scientists had more precise knowledge about the temperatures of the interiors of distant stars than they did about the temperatures inside a cooking souffle.
That's all changing, thanks to the efforts of people like Parisian scientist Herve This (pronounced "tiss") at the College de France's Laboratory for the Chemistry of Molecular Interactions, whose research has led to far greater understanding of the chemical units involved in food and cooking: fats, carbohydrates, proteins, and the like. This' book on the subject, Molecular Gastronomy: Exploring the Science of Flavor, has just been translated from the French. It's frankly a bit dense for more populist palates, but I did pick up a couple of fascinating tidbits:
(1) Americans can't hard-boil an egg worth a damn. The usual 10-minute cooking time at the boiling point for water causes too many of the proteins to gel, according to This, leading to rubbery egg whites.
(2) It's a myth that cooking meat at high temperatures seals in the juices, and it makes no difference whether you season steak with salt before or after cooking. Either way, the salt never penetrates deeper than the surface of the meat.
The "bible" on the science of food and cooking is, well, On Food and Cooking, by Harold McGee, first published in 1984, with a revised, updated edition published in 2004. (You can read an in-depth interview with McGee in the February 18, 2006 issue of New Scientist here, although a subscription is required to view the full article online.) It's written in engaging, plain English, and is well worth the purchase price. McGee is also the author of The Curious Cook, which contains his own experiments and answers to such pesky questions as whether washing mushrooms makes them soggy (no), and whether it's possible to make mayonnaise without egg yolks (yes).
Molecular gastronomy should continue to yield exciting new insights and innovations, thanks in part to the ongoing series of International Workshops on Molecular Gastronomy. McGee, This, British physicist Peter Barham, and various other chefs, food critics and other gastronomic types gather annually for these meetings. A texture workshop five years ago, for example, explored foams and gels, the biomechanics of chewing, even the fractal nature of baba au rhum dough. Who knows what tasty discoveries subsequent workshops will uncover, which chefs can then bring home to their kitchens, applying those breakthroughs to create even more culinary delights?
My physics palate salivates at the prospect.