In September, talking to an audience of chefs from around the world, Wylie Dufresne of WD-50 on the Lower East Side of Manhattan waxed enthusiastic about a type of ingredient he has been adding to his restaurant’s dishes.
Not organic Waygu beef or newfound exotic spices or eye of newt and toe of frog, but hydrocolloid gums — obscure starches and proteins usually relegated to the lower reaches of ingredient labels on products like Twinkies. These substances are helping Mr. Dufresne make eye-opening (and critically acclaimed) creations like fried mayonnaise and a foie gras that can be tied into a knot.
Chefs are using science not only to better understand their cooking, but also to create new ways of cooking. Elsewhere, chefs have played with lasers and liquid nitrogen. Restaurant kitchens are sometimes outfitted with equipment adapted from scientific laboratories. And then there are hydrocolloids that come in white bottles like chemicals.
Xanthan gum, for instance, a slime fermented by the bacteria Xanthomonas campestris and then dried, is used in bottled salad dressing to slow the settling of the spice particles and keep water and oil from separating. Xanthan and other hydrocolloids are now part of the tool kit of high-end chefs.
“These ingredients are finding more and more of a footing in the traditional, free-standing restaurant,” said Mr. Dufresne (pronounced doo-FRAYN) at the Starchefs International Chefs Congress in New York.
He noted that the hydrocolloids he uses came from natural sources and often had a long history in the cooking of other cultures.
“In our ongoing search of working with hydrocolloids, we’re always trying to find interesting and new things and new applications,” said Mr. Dufresne, who at times sounded as if he were talking to chemists rather than chefs.
And rightly so. Cooking is chemistry, after all, and in recent decades scientists have given much closer scrutiny to the transformations that occur when foodstuffs are heated. That has debunked some longstanding myths. Searing meat does not seal in juices, for example, but high heat does induce chemical reactions among the proteins that make it tastier. The experimentation with hydrocolloids represents a rare crossover between the culinary arts and food science, two fields that at first glance would seem to be closely related but which have been almost separate. Food science arose in the 20th century as food companies looked for ways to make their products survive the trek to the supermarket and remain palatable. The long list of ingredients on a frozen dinner represents the work of food scientists in ensuring shelf life and approximating the taste of fresh-cooked food.
“Ten years ago, or maybe a little more than that, no chef in a serious restaurant would be caught dead using these ingredients,” said Harold McGee, author of “On Food and Cooking” (Scribner, 2004) and the “Curious Cook” column, which appears in the Dining section of The New York Times. “Because they were industrial stabilizers for the most part.”
Then a few chefs like Ferran Adrià in Spain and Heston Blumenthal in England started experimenting. “They asked what can you do with these ingredients that you can’t do with other ingredients,” Mr. McGee said.
Despite its imposing name, a hydrocolloid is a simple thing. A colloid is a suspension of particles within some substance. A hydrocolloid is a suspension of particles in water where the particles are molecules that bind to water and to one another. The particles slow the flow of the liquid or stop it entirely, solidifying into a gel.
Cornstarch used as a thickener is a hydrocolloid. So is plain flour. But the properties of hydrocolloids differ widely, depending on their molecular structure and affinity for water.
Today, Grant Achatz, chef of Alinea in Chicago, uses agar-agar, which is a hydrocolloid made from seaweed that is best known for growing bacteria in petri dishes, and gelatin, a more familiar hydrocolloid made from collagen in meat, to make transparent sheets that he drapes over hot foods. For a dish made of a confit of beef short ribs, he wanted to add a taste of beer so he draped a veil flavored with Guinness on top — “a thin, flavorful glaze that ensured the diner would get some beer flavor in every bit of the dish,” Mr. Achatz said. Plain gelatin would simply melt, and ruin the effect.
