Koji

Koji is a mold culture grown on rice, barley, or soybeans that initiates fermentation. It is the basis of miso, soy sauce, and sake production. It breaks starch down into sugar and protein into amino acids, creating umami flavor.

Where It’s Used

“Sprinkle store-bought koji starter (Aspergillus oryzae spores) over steamed rice and let it grow mold in a warm place.”