koji

Technically a fungus, koji is one of Japan’s most treasured natural resources, used as the foundation of soy sauce, miso paste, saké and shochu. When introduced to barley, rice, or another base ingredient, koji creates an enzyme that converts starches to sugars so yeast can step in and begin the fermentation process. In beverages like saké and shochu, this happens in a process called “multiple parallel fermentation” where the koji and the yeast are doing their respective jobs at the same time.