Multiple Parallel Fermentation
Sake is produced by the multiple parallel fermentation of rice. This method is different from other liquor such as beer and wine. Unlike malt for beer, rice for sake does not contain the amylase necessary for converting starch to sugar and so it must undergo a process of multiple fermentation. The addition of Koji mold (Aspergillus oryzae) provides the necessary amylases, glucoamylases, and proteases to hydrolyze the nutrients of the rice to support the growth of the yeast. In sake production these two processes take place at the same time rather than in separate steps.