After cooling down, the steamed rice is used for making Koji, Shubo and Moromi. There is a general phrase expressed as "Koji comes first, Moto(Shubo) comes second, and Tsukuri (Moromi) comes third" so these processes are very important.
Koji is an essential thing to make sake, soy sauce, miso and mirin. Rice koji is steamed rice onto which koji mold has been cultivated. The role of rice koji is to release enzymes that break down starch into glucose. Rice koji can be made by machine but we have been making it by hand. Especially, when rice koji of Daiginjo is made, it's divided into small wooden boxes to control temperature strictly.
Making Shubo (Yeast starter)
Shubo is made by mixing steamed rice, rice koji, water and yeast in a small tank. As the meaning of Shubo represents the mother of sake, the number of yeast increases inside shubo. There are various kind of sake yeast, which affect the taste and the aroma of sake. One of the biggest characteristic of Dewazakura is fluty aroma called Ginjo-ka coming from the yeast.
Making Moromi (Mash) / Fermentation
Shubo is transferred to a large tank, where steamed rice, rice koji and water are gradually added three times. This mixture is called Moromi and this process is called Sandan jikomi. Sandan jikomi is done over a four-day period so as not dilute the acidic environment. By promoting a fermentation slowly at low temperature, clear tasted sake can be brewed.
When a fermentation is completed, it is pressed to separate the newly created sake from the solid remains of the fermented rice called Sake-kasu. Especially, when Moromi of Daiginjo is pressed, the drops of sake are collected in bottles without any pressure to the moromi. This special way is called Fukuro-tsuri or Tobin-gakoi.