Koji mold genus (Koji kabi zoku)

Koji mold genus (koji kabi zoku) refers to a group of molds classified in the genus Aspergillus, which play an important role in producing fermented foods, including sake (nihonshu) and shochu. The group includes yellow koji mold (ki koji kin), used in sake brewing, and black koji mold (kuro koji kin) and white koji mold (shiro koji kin), used in shochu production. These koji molds grow on grains such as rice and barley and convert starch into sugar, which promotes fermentation during brewing. Because the choice and cultivation of koji mold greatly influence the flavor and aroma of the finished sake, it is an important consideration for brewers.