A caveman from the Paleolithic Era and Chef Andoni Luis Aduriz from the venerable San Sebastián restaurant, Mugaritz, have a common bond that goes beyond their shared humanity. Stone Age man "invented" fire and consequently was the first to taste cooked food coated in ash. Some 1 to 2 million years later, Aduriz was so taken with this precedent setting procedure that he intentionally (and carefully) refined the technique for his menus, contributing immensely to the popularization of the fortuitous and ancient application in a modern fine-dining setting.
"I was curious and inspired by Aduriz's book, [Mugartiz: A Natural Science of Cooking (Phaidon Press: 2012)], where veal was covered in vegetable ash," says Frank Liao, sous chef to 2005 Rising Star Chef David Bazirgan at Fifth Floor restaurant in San Francisco. He and Bazirgan took this inspiration and created a dish in which ash is a central component: Beet Ash-Coated Loin of Venison, Maitake, Red Cabbage, Pistachio, Mastic, and Porcini Jus. It's a composition that "represents the dark and cold nights of winter," Liao explains.
Loin of Venison, Maitake, Pistachio, Vegetable Ash, Mastic, and Porcini Jus with Ponce P.F. Bobal, Manchuela 2009
"The beet ash came out dark and smoky. I added mastic cream [to the dish to express] the surroundings where the venison may have roamed. Pistachio adds richness. Red cabbage provides acidity and balance. Porcini jus is earthy. When the dish came together, it was seasonal and had charred and roasted flavors [from the beet ash]."
Liao looked to his inner-caveman when tinkering with technique to produce an ash with which he was satisfied. He found that the key to a good ash is the embers. "Just imagine a fire after a huge BBQ. Tightly wrap the beets in aluminum foil and cover with the embers. Let the beets sit overnight. You should have enough embers so that they dry out [and char] the beets entirely."
Fifth Floor has a charcoal grill, so Liao uses the glowing embers that remain after a dinner service. Alternatively, the beets may be sliced about ½-inch thick and charred in a 500°F oven until completely dried and burnt. For both methods the red root vegetables are not peeled before blackening. When they've cooled, the ashes are pulverized in a food processor and passed through a chinois. The process can get a little messy but Liao finds the result worth the sting of ash in his eyes because the affect is more intense than the flavor one gets from either smoking or grilling.
The ashes are easily stored in an airtight container at room temperature. And since the beets are readily available in winter, they were a cost effective product to utilize. But every conceivable vegetable is a potential candidate for this charring technique any time of year. Ash is also a versatile ingredient. At Fifth Floor Bazirgan and Liao use leek ash and eucalyptus oil to embellish onions for various other seasonal dishes.
Liao mixes his beet ashes with olive oil and applies it to venison portions as a marinade that adds flavor, moisture, and a deep dark hue. Upon plating, the pan-roasted venison—that has been gently basted in butter and thyme—resembles the very charcoal that charred the beets in the first place. It's a full circle journey from charcoal to charred; an odyssey unfathomable to the early-man that first put deer to fire ages ago.
Technique for Making Beet Ash
Trim beets, remove tops, scrub under cold running water, and dry on paper towels.
Wrap individual beets tightly in aluminum foil.
Cover beets with hot glowing charcoal embers and let char overnight.
Carefully open foil and transfer charred beets to food processor; process to ash.
Pass ash through chinois.
Store beet ash in airtight container at room temperature.