The most important thing in sake brewing is koji brewing.

The room (Muro) / Jiuqu room (Seikikushitsu) is located at the end of a heavy door with strict temperature and humidity control.

Steamed and seeded rice is lined up in the machine, and aspergillus is propagated.

"Cut back" is performed so that the temperature during breeding does not rise too much.
An "automatic koji making machine" is used, but in the end, the brewer's hands check the feeling and loosen it.

After that, the Jiuqu that has been worked in the Jiuqu room is spread and dried.
It is called "Jiuqu".

It's a pure white Jiuqu.
After this, the preparation is done.