Koji — the mold-innoculated grains — has become one of the superstars of the American fermentation scene, thanks to chefs experimenting with it in unique ways. Dubbed “Japan’s mold,” koji has been a cooking staple in Asian countries since the 1800s. In a webinar with Chelsea Green Books titled “Breaking the Mold: A Conversation with Fermentation Fanatics,” Sandor Katz, Rich Shih and Jeremy Umansky discussed how koji can be used for fermenting foods.
“I think one of the fascinating things is to see these microbial sets start to be viewed through different cultural lenses across geographic locations,” says Umansky, co-author of the book “Koji Alchemy” with Shih. “We’re honestly starting to see food the world has never seen before. It’s a really exciting time to be fermenting, to be growing koji and making the foods that are being made from it.”
Applying ancient fermentation techniques in new ways is a “game changer” to a dish, Shih added.
“You don’t need a lot to make it really mind blowing,” Shih says. “When I started thinking about how little of these umami-blasted product I added to make it delicious.”
“I think one of the coolest things that I discovered about working with koji is it’s just that little bit of breakdown that creates that umami that really brings the product to life. You need such a small amount of protein to make a big difference,” Shih adds.
Mold has a bad reputation as the fuzzy invader that grows on old food. But, Shih points out, everyone has tried mold. Koji mold is a driver for soy sauce, one of the most popular condiments worldwide.
“When people start, they have a perception of what mold is and this perception that it’s not good for you, it’s bad, and it should not be part of food,” Shih says. “Mold is a wonderful thing and it creates all these wonderful condiments and drinks that allowed us to be here today, to survive those times when it was tough and preservation was necessary.”
Katz, who is releasing a new book on fermentation “Fermentation as a Metaphor,” joined Umansky and Shih for their conversation (TFA is hosting a webinar with Katz and Mara King on October 7.). A fermentation author and educator, Katz has taught hundreds of workshops on demystifying fermentation.
“All three of us would say: experiment. You can grow koji on virtually anything,” Katz advises.
Today, there are powder koji starter cultures available to purchase for cooks to create koji dishes. Until the 20th century, there were no koji starter cultures, Katz points out, as cooks used mold spores in the air.
“We can order cultures to make this happen today. It’s very very much in our reach,” he says. Addressing Umansky and Shih: “You guys figured it out just by playing in your kitchen. None of this is that hard.”
However, Katz says koji is not a first fermentation project. Koji requires a controlled temperature environment and humidity. Vegetable fermentation is a beginner-friendly fermentation project because it merely involves vegetables and salt.
“There is a small, minute risk that something may go wrong,” Shih says. “We always encourage people when they’re first starting and thinking about growing koji in this fashion is to grow it in the most controlled way possible to be successful.”
Umansky encourages those ready to start fermenting with koji to buy a starter from a reputable producer. Especially important is purchasing spores from a location in the geographic area where the kojis were domesticated. In researching the book, Umansky found there is only one of seven companies left in Japan that still produces koji spores, Higuchi Matsunosuke Shoten Co., Ltd. Owner Koichi Higuchi is the head of the 7th generation company. Higuchi has a vault with hundreds of variations and specialties of different koji species.
“These are people that are really, really driving the preservation of kojis worldwide,” Umansky says. “Supporting them drives the preservation of this…they’re working really hard to protect the biodiversity that’s important for their individual cultural identities.”