Rice Polishing (Milling)
The outer layers of unpolished rice contain large amounts of fats, minerals and proteins that will spoil the flavour of sake, thus the rice is polished using a high-speed rotating roller at the beginning.
For example, the polished rice with a remaining core of 70% is known as 70%- polished rice or is said to have a Seimai-buai (精米步合) of 70%.
Depending on how much the rice is polished, the sake is classified accordingly.
.png)
rice washing & soaking
After milling, the rice is then washed and soaked.
The process of soaking rice is called SHINSEKI (浸漬）. Time for soaking depends on how much the rice is polished. The more it's polished, the less time it requires to absorb water.
rice steaming
After the grain has absorbed around 30% of its weight in water, it's removed from the water and steamed for about an hour.
The steamed rice will then be used for 1) Koji-Rice 2) Shubo and 3) Moromi