Koji [麹], Koji-Kin [麹菌] is a type of mold used for Sake brewing. Its technical name is aspergillus oryzae, which is widely used in Japan and other East Asian countries to make alcohol. In Sake making, Strictly speaking, the fungus is called Koji-Kin. Koji means the steamed rice (or other grain) molded with Koji-Kin.

Koji is said the most important ingredient in Sake making. Healthy Koji produces enzyme to convert the starch in the rice into sugar, which is then turned into alcohol by yeast. Koji starts the magical process of Sake brewing.

This is the first home-making of Koji at Sake South. It may take several trials, but our Batch #5 will be brewed with home-made Koji. Koji starts the magic.