Moromi / Rice Mash / Fermentation 

Moromi, a term used to describe an “all-components-assembled, actively-fermenting” tank of sake elements… is not yet considered sake. The term sake is not applied until the end of fermentation. Assembling or building a tank of moromi entails a four-day process of three separate additions of: freshly-steamed rice, koji, and water. Each addition is approximately twice the volume of the preceding addition although the ratio of the three components changes with each addition depending on the grade and style of sake. The percentage of koji is reduced with the second and third additions, while water and freshly steamed-rice volumes are increased to support alcohol fermentation activity.

Each fermentation is unique and operates according to its own dynamics. In general fermentation requires three to five weeks to complete, and although young, raw and brash… it has arrived at a “state of sake”.