Saké rice wine fermentation

Saké , a Japanese traditional alcohol beverage is produced by saccharification of rice starch by koji and alcoholic fermentation. Sake making has developed into a modern fermentation industry, producing clear, pale-colored rice wine with alcoholic content of 1% - 16% or higher. It has characteristics flavor and aroma, small amount of acid and slight sweetness.

Raw materials for saké: water used for saké should be colorless, tasteless and odorless, neutral or weakly alkaline, and substantially free of iron, nitrate, ammonia, organic substance and harmful organisms.

Rice of the short-grained varieties is considered best for saké manufacture and large grains are considered desirable.

The characteristics features in saké brewing are the use of ‘koji’ a culture of Aspergillus oryzae grown on and within steamed rice grains and parallel fermentation by saké yeast.

The first step is the preparation of milled rice and its steaming. This followed by the preparation of koji and the preparation of moto mash, starter for saké yeast prepared by mashing steamed rice, koji and water. The moto bubbles for a few days in a warm environment.

Koji and water are added in the evening, then the next morning more rice is added. Once all the rice has been incorporated, the rice mash is known as moromi.

The main fermentation takes 20-25 day. When fermentation has ceased the moromi mash is filtered to remove the solids; the filtrate thus obtained is fresh saké. After about a month, the fresh saké is pasteurized and stored.
Saké rice wine fermentation