Sake processing begins when short grain brown rice is polished to white rice, removing the hick and surface fats, amino acids, and minerals which would disturb the clarity and the flavor of the final product, leaving a core that approached pure starch.
Making rice malt is the heart of sake brewing. Koji mould, Aspergillus oryzae is sprinkled on the steamed rice after cooling the rice.
Koji is a basically a preparation of mould-covered rice, in which hydrolytic enzymes, such as amylases, protease and lipases are present in a stable mixture.
The main alcohol fermentation is started by moving yeast starter and adding water steamed rice and rice malt to larger tanks.
The temperature and other factors of the alcohol fermentation process are measured and adjusted to create the flavor and taste profiles of the sake product.
The yeast in the starter reaches it maximum strength after about two weeks. At that time, additional large quantities of steamed rice, koji rice and water are added to produce the final mash.
After the fermentation, the mash is pressed with filter press to remove the white lees and unfermented solids, and clear sake is obtained.
The strained sake is chilled and allowed to sit for another ten days while enzymatic changes continue to occur.
The normal alcoholic content of sake is around 15% volume per volume, although it can reach 20%. Sake in its finished form is about 80 percent pure water.
The brewing of sake
