Rice koji is steamed rice in which a filamentous koji mold is grown. The theoretical name of the mold is Aspergillus Oryzae. The spores of the mold is called koji-kin or koji-spore. Koji has several magical enzymes. Koji is important not only in making sake but also to make soy sauce, miso, amazake (sweet rice drink), mirin (sweet sake), koji pickles, shio-koji (or salt-koji) and shoyu-koji. Indeed, koji is the foundation of Japanese foods. The important...