WHY, THEN, IS foam now reappearing at new restaurants, from an effervescence of yuzu over oysters at Chateau Hanare in Los Angeles to an aerated lobster bisque presented like a crashed ocean wave over a fillet of hake at Simon & the Whale in Manhattan? How is this most cerebral emblem of gastronomy relevant to our time, when comfort food is ascendant and high-end chefs are downshifting to fast-casual concepts, when even the most daring diners have retreated to more immediate and fundamental pleasures? Our obsession with provenance — where ingredients come from, how animals are raised and butchered, whether vegetables arrive in the kitchen with dirt still clinging to their roots — and our yearning to reconnect with the land both seem incompatible with a form of food that bears no visible relationship to its origins, more engineered than cooked.
But foam isn’t, in fact, a modern invention. For centuries, we’ve found ways to put air into food, to build volume and evoke ethereality. An unknown cook in 17th-century Europe hit upon the notion of beating egg whites — causing the proteins to unfold and stretch out so they can trap air — until they stiffen into alpine peaks that defy gravity when the bowl is overturned; thus meringue was born. The French word “mousse,” as the former food editor Craig Claiborne pointed out in The Times in 1971, “means froth, and that’s all it is — a bit of fluff made stable with a touch of gelatin.”
From a scientific perspective, foam is a fairly routine component of our diet. Air is churned into ice cream and trapped when it’s frozen. An espresso is half judged by its crema, a latte by its halo of milk, a beer by its head. The quality of the bubbles in Champagne is so crucial to its charm that a laboratory in Reims, France, is dedicated to studying their consistency. Even something as solid as bread is technically foam: Yeast devours sugars and releases carbon dioxide, pockets of which get trapped inside a matrix of dough.
To the French physical chemist Hervé This, who helped create and give name to the discipline of molecular gastronomy — the scientific study of what occurs during food preparation and consumption — foam is “an old story.” He proposed taking scientific equipment from the laboratory to the kitchen in the 1980s, “to enlarge the possibilities for the chef,” he says. On one level, it was about practicality: “Why wait for five minutes if you can get the same result in 30 seconds?” A siphon is no more radical than a microwave, and no less.
It might be expected for foam to once again be a showpiece at avant-garde restaurants, like the spiky hot-pink dragon-fruit cloud at the haute Bazaar by José Andrés in Miami Beach. But what’s noteworthy is its unheralded incorporation into dishes at less esoteric spots. At La Vara, Raij once honored a classic Spanish combination — a specialty of the region of Mallorca, where her husband worked as a young cook — by serving sobrasada, a pork sausage laced with paprika and creamy enough to spread like pâté, under a sluice of honey foam. (She credits the chef Wesley Genovart of SoLo Farm & Table in South Londonderry, Vt., for the idea of whipping the honey.)
Nor are today’s foams always reliant on a siphon: Matt Griffin, the executive chef of Simon & the Whale, uses a hand blender so that his bisque still has a texture that suggests soup, albeit one with extraordinary lightness; Raij whips her honey in a stand mixer, like a meringue, preferring a looser structure to the iSi’s shaving-cream-like billows. Neither chef finds it necessary to note the presence of foam on the menu. For Raij, aerating is simply another technique, a way of “layering different densities of flavor” on a plate, applied as needed. Griffin sees his food as “rooted in the basics,” he says; it just so happens that “the basics are changing.”
Foam may never again be the shocking thrill it was for the first tasters of meringue in the 17th century or for diners at El Bulli in 1994. Once revolutionary, then despised as a cheap trick and sleight of hand, it’s now joined the culinary canon, a mechanism rather than an end to itself. And in truth, it always was. While Adrià certainly wanted to break barriers, he wasn’t a provocateur; what guided his investigations was a desire to appeal to the senses. He was a chef. He made food, and he nourished us.