Sometimes the secret's not just in the sauce. It's in the murky, funky, umami-ful, not-so-attractive gunk that's left behind when the sauce is processed. Just ask Levon Wallace, Louisville chef of Proof on Main and lucky recipient of the dregs pressed from Bluegrass soy sauce.
For the uninitiated, Matt Jamie's Bourbon Barrel Foods is the only company in the United States that produces artisan soy sauce. He has no competitors. Big-time operators like Kikkoman and Yamasa collectively make a generic 30 million gallons a year in their U.S. factories; Jamie sells about 5,000 gallons each year (he jokes, "as much as Kikkoman spills in a day"). Like any small, serious artisanal producer of beer, wine, bread, or charcuterie, Jamie's Bluegrass soy sauce is full of nuance with smoky notes and hints of vanilla and wood, thanks to time spent aging in Woodford Reserve bourbon barrels.
Since its launch in 2007, Bluegrass soy sauce has made its way into the kitchens of some of the region's and country's best chefs: Rick Tramonto, Sean Brock, Ed Lee, and Anthony Lamas. Wallace just happens to get a special piece of the action. "When Matt's done processing the soy sauce, he lets me have the mash," he says.
Koji Fermentation Room
Bourbon Barrels with Fermenting Soy Sauce
Matt Jamie of Bourbon Barrel Foods, Louisville, KY
Soy Mash Is Born
Before there is soy sauce or mash, there are soy beans (with added red winter wheat in the case of Bluegrass). Jamie roasts the soy beans and grinds the wheat before inoculating them with yeast (koji); he then leaves them for two and a half days to develop a yellowish koji mold. Next he combines the moldy soy-wheat mixture with a solution of sea salt and spring water, and this moromi (Japanese for mash) is the living, breathing, fermenting mixture that gives soy sauce its distinct character. For about six weeks, the yeast survives in barrels as it undergoes open-air fermentation and gobbles up the nutrients from the moromi. Once the fermentation stops, Jamie ages the soy for another 10ish months in bourbon barrels—about a year in total for the process.
Because he's working on such a small scale, Jamie's team uses a cider press to help separate the moromi solids from the liquid. The resulting soy sauce gets pasteurized, bottled, and shipped across the country. The leftover wet soil-esque paste—or soy sauce cake, as it's referred to on an industrial scale—makes it to a handful of chefs. (Jamie hasn't quite figured out how to package and sell the stuff, but we'd recommend courting his favor for when that day comes.)
For the Cows
Wallace likens the leftover moroni solids to miso, and the comparison is apt with a few nuances. Miso is essentially soy beans and/or wheat fermented with koji. The koji never dies off in miso, however, and continues to ferment (the koji in moroni is dead and fermentation has ceased); plus, the open-air fermentation of soy sauce results in a darker color and deeper flavor than miso. The terminology for making the products overlaps, as it does with sake—another fermented liquid whose dregs are used in culinary applications. Unlike miso or sake lees, though, pressed soy sauce moromi has only weak ties to the kitchen.
As early as the 15th century, soy sauce makers pressed oil from the mash to fuel lamps, and they fertilized crops and fed pigs with the rest. Kikkoman continues the practice today, running machines off the oil and selling the soy sauce cakes to cattle farmers. Jamie simply discarded the mash, until chefs started knocking.
One man's cow fodder is another man's culinary inspiration. "Chefs are drying out [the leftover moromi] and use it to season things, making compound butters, sprinkling it on sashimi, adding it to broth and breads. They're making kimchi and curing pork and fish. There's a lot of flavor left in it," says Jamie.
Wallace takes the moromi and smokes it over bourbon barrel wood. In the process, he transforms a mixture along the lines of wet coffee grounds into hard, coal-like pellets. "It looks like fossilized dung, but it's an umami bomb with notes of soy, tobacco, and chocolate," he says. He then grinds the smoked moromi and uses it as a salty-smoky dry rub for pork belly. Accompanied by pumpkin mustard, a moromi-infused pork jus, Bluegrass soy-pickled shiitakes, and a final garnish of the smoked moromi, Wallace's dish tastes like fancified barbecue—with its smoke, char from the grill, and tangy mustard sauce. But it's a whole lot more: haunting, rich, resourceful, elegant, fun.
Jamie and his cadre of moromi-slinging chefs have thrown out the rule book on hundreds of years of Japanese tradition. They're snatching soy sauce mash from pigs and cows and bringing its full-flavored funk to the people. (Though, we'd love to see it come full circle with moromi-fed pigs bathed in a soy sauce-moromi marinade. Just saying.)