Bunji (wooden tool used in koji making)

Bunji is a wooden tool used in the sake-brewing process, particularly in koji making (seikiku). It is used to break up clumps of hardened steamed rice. Specifically, it loosens the layer of steamed rice needed to promote koji fermentation and lets air pass through, helping fermentation proceed evenly. Using a bunji allows the koji mold to spread evenly, which contributes to better sake quality.