Koji: Fermentation’s New Star Microbe
By Amber, CN Buyer, Educator + Fermentation Enthusiast
As Cambridge Naturals' resident fermentation nerd (and regular volunteer at the Somerville Fermentation festival), I'm always excited when an unusual ingredient turns up on our shelves. Recently, the star of the show is koji - specifically Koatji, a koji-cultured oat milk that arrived at Cambridge Naturals recently. But what exactly is it?
Koji is a type of fungus (species Aspergillus oryzae) that is used to ferment foods. It's commonly grown on rice, but buckwheat, oats, soybeans, and wheat can also be used. During the fermentation process, the enzymes in the koji break down proteins and carbohydrates in the grain, producing sugars and amino acids that give the final product a sweet, umami flavor. Difference strains of koji mold, fermentation conditions, and substrates can produce different flavor profiles. The fermentation also makes the nutrients in the grain easier for the body to absorb!
Koji-fermented foods are a hallmark of Japanese and Chinese cuisines. Koji is used in the production of things like miso, sake, and soy sauce. But koji also has cultural connections to the cuisines of Korea, the Philippines, Pakistan, and Indigenous Australia. The universality of fermented foods is visible in the diverse communities that utilize koji in their dishes.
Despite being an ingredient with thousands of years' worth of history, koji is a relative newcomer to Western palates. However, you'll find it popping up in all sorts of new products, from snack foods to smoothies. And local bar The Koji Club has been highlighting the wonders of sake in an inviting space for several years now - if you haven’t checked them out, it’s worth a visit!
The koji renaissance blends centuries of tradition with modern innovation, and I'm anxiously awaiting what new koji-based products will appear next. For now, I can't wait to play around with Koatji more in my kitchen (Koatji ice cream, anyone?)!