Koji is a fermented fungus that's been used for centuries to break down grains and legumes, making their nutrients more bioavailable. You're not eating the fungus itself, but rather the nutrient-rich food it's transformed. It's a traditional tool in many cuisines, from Japanese miso to African sorghum.
Did you know
The mold that makes miso, soy sauce, sake, and mirin possible — Japan's national fungus.