Ashes from burnt food, wood, or hay are being put on food (and food is being cooked directly in hot ashes) at upscale restaurants around the country, but this trend is not some last-ditch attempt to salvage burnt food. The chefs who are using it—mostly inspired by René Redzepi of Denmark's Noma (a.k.a. "the best restaurant in the world")—say it adds bitter and smoky flavors to their dishes. And the culinary use of ash isn't quite as out there as it sounds: Ash has long been used in ancient food preparations by Native Americans, and in traditional Scandinavian foods like lutefisk and preserved herring—where, Redzepi says, he got the idea in the first place.
Spotted a few weeks ago at the modern Cal-Moroccan restaurant Aziza in San Francisco as a jet black garnish sprinkled on chestnut soup. The ashes were crunchy, a little like chewing smoked coffee grounds. Also spotted at Castagna in Portland, Oregon, where Chef Matt Lightner makes hay ash, then purées it with olive oil, rubs it on black cod, and leaves it to cure for a week, before smoking the fish (using more hay) and slicing it.
At Gilt in New York City, Executive Chef Justin Bogle chars onion hearts until they are black and purées them with honey to serve with beef strip loin. The dish is garnished with onion ash, which takes about six or seven hours to fully burn. Bogle freely admits that part of the appeal is how cool ashes look on a plate aesthetically.
In Chilhowie, Virginia, at the Town House, Executive Chef John B. Shields burns eggplants into ash, which is served with lamb in a presentation that looks like an installation art piece (see photo). His dish also includes sifted wood ashes from the restaurant's wood-fired grill, and the lamb itself gets about a 30-second stint directly in the hot ashes and embers after being cooked sous vide. Shields sees the ash trend as part of the fine-dining pendulum swinging back from the chemical manipulations of food that hit big around 2000. "Now it's settling into a groove of taking natural elements [like ash] and then using some modern technique to push the envelope."
Over this summer in San Francisco, Chef Joshua Skenes went so far as to install an eight-foot wood-burning hearth at Saison. He recently served a dish with leeks, Vidalia onions, and wild onions that had been buried directly in the hot ashes to cook. "Fire is the purest form of flavor," he says. "I'm at a point now where I want to strip down the whole restaurant and build a giant fire pit and cook everything over it."