Breaking the Mold

It's time to get acquainted with koji, the seasoning ingredient chefs can't get enough of

Forget unicorn lattes. This year's biggest food trend is mold.

We're talking about a traditional Japanese ingredient called koji, and with the country's brightest chefs, from David Chang to Sean Brock, experimenting with it, you're going to want to pay attention.

Although koji, dubbed Japan's national mold, has been a culinary mainstay in Asia for centuries, it's only recently that Western chefs have started catching on to its transformative powers as a seasoning and a curing agent.

It's not eaten on its own, but grown on partially or fully cooked grains, such as rice and barley. As the spores begin to flourish, enzymes convert the grain into sugar, and then the enzyme-rich grain is added to a second product, such as soybeans. This secondary fermentation process causes a complete transformation in flavor and texture. It's how soybeans become miso, rice becomes sake, soybeans plus wheat become soy sauce. This resulting flavor you know and love? Umami.

As David Chang put it in a 2013 koji-focused lecture on fermentation, "Microbes produce enzymes, enzymes develop amino acids, glutamic acid + aspartic acid = umami, umami = delicious."

Sandor Katz, author of The Art of Fermentation, who uses koji in traditional applications like sake and miso, as well as in bread making and marinades, cites "the growing interest in fermentation" for the budding koji trend. "We are in an exciting period of innovation where chefs are taking ancient processes that have been used in very specific ways, and applying them to new ingredients or in new ways."   

In its natural state, koji smells floral, yeasty and citrusy, and it was this intoxicating bouquet that inspired Jeremy Umansky, master larder and forarger at chef Jonathon Sawyer's Italian restaurant, Trentina, to experiment with the mold. When he was researching house-made chickpea miso, Umansky found that koji's sweet scent reminded him of a fresh scallop. After discovering he could grow koji not just on rice but also on rice flour, the chef coated scallops in rice flour, spread the spores directly onto the flour and left them in a dehydrator. Thirty-six hours later, out came fungus-coated scallops that were neither spoiled nor rank, but instead perfectly cured with firm flesh that smelled of sweet citrus and brine.

From his successful experiment with scallops, Umansky has gone on to use koji to cure heartier proteins, such as beef, lamb, chicken, pork and even llama. With koji, he is also able to make traditional charcuterie in days instead of weeks, using no salt at all. He's gotten so into the Japanese mold that later this fall he'll be opening Larder, a European-style delicatessen in Cleveland where every product from bread to pastrami has been, in his words, "kissed by koji."

Momofuku uses koji in its soy-free miso-style paste called Hozon, which is made from koji-cultivated basmati rice and various nuts and legumes, such as sunflower seeds, chickpeas and pistachios. At Emmer & Rye in Austin, chef Kevin Fink makes koji-grain griddle cakes, and at Mission Chinese in NYC, chef Danny Bowien serves Hainanese-style koji fried chicken.

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Meanwhile, down in Charleston, South Carolina, at McCrady's Tavern and McCrady's, Brock uses koji in almost every menu item as a way to "boost flavor." Adding koji to classic Southern dishes helps him unlock the hidden depth of flavor in indigenous ingredients. As he puts it, "If we can inoculate [Anson Mills] Sea Island red peas and make red pea koji when we make a simple dish of hoppin' John, it tastes extraordinary. And to me, that's the beauty of soul food: the idea of taking nothing, or almost nothing, and making it extraordinary. That's survival cuisine."

With the growing interest in fermentation across kitchens of all stripes, Umansky predicts that in the next two to three years, chefs will be using koji in as many products as they can. "It's just a home run once people start using koji," he says. "Once you destroy the fear of the unknown, these processes become extremely simple and applicable across a wide variety of cuisines."

Sari Kamin is a food writer and the host of Food Without Borders on Heritage Radio Network. She lives in Brooklyn with her dog, Max. Follow her on Instagram @sarikamin.