Koji-muro
麹室
Definição
The dedicated temperature and humidity-controlled room where koji is cultivated over approximately 48 hours. The koji-muro is kept at 28-36 degrees Celsius and is the most carefully managed space in any sake brewery.
Em Profundidade
The koji-muro is typically a small, insulated room with cedar-lined walls that naturally regulate moisture. Inside, steamed rice is spread on wooden trays or tables and inoculated with tane-koji. Over two days, the brewer monitors temperature and moisture, turning and redistributing the rice at precise intervals to control mold growth. The room is often considered sacred — many kura restrict access and require quiet to avoid disturbing the delicate cultivation process. Modern breweries may use stainless steel rooms with digital controls, but the principles remain unchanged.