How is Sake Made?---The Rice

Recently, I have been blogging about sake:

• The Sake Shop in Honolulu
• The Book of Sake A Connoisseur's Guide
• 2020 Kamoshibito Kuheiji Eau du Desir Junmai Daiginjo

I wanted to learn more about the sake making process and found an excellent guide online: How is Sake Made? Not only is this site informative, it is beautifully illustrated.

Rice, water and koji are the three ingredients that are essential for making sake. It is like wine and beer in that it requires fermentation but the process of fermenting rice into sake is unique.
The Rice
As of 2020, there are approximately 900 strains of rice, out of which 126 are sake rice. Sake rice tends to be larger in grain size compared to table rice. It is suitable for sake brewing because of its digestibility and low protein content.

• The first step is polishing the rice. The outer brown part of the unpolished rice is high in fats, proteins and other nutrients. If the rice was not polished, these fats and proteins would lead to a sake with a musty aroma and maybe some unwanted flavors, Therefore, the outer portion of the rice is ground away leaving the starchy interior. The degree of polishing determines the quality of the sake. The further the rice is polished, the clearer and cleaner will be the resultant sake.
• The grinding of the outer surface of the rice creates heat that is retained by the polished rice so there is a cooling off period called the karashi. The karashi is also a time for the rice to absorb moisture from the air so that the grains will not crack when it is washed.
• After an appropriate cooling off period has elapsed, the rice is washed. For the highest grades of sake, the rice is hand washed, but the process is becoming increasingly mechanized.
• The rice is then soaked after washing. The soaking time depends on the temperature of the water, the quality of the rice, the grade of polish, and the water content of the polished rice. After soaking the water is drained and left overnight. This soaking period can be as short as minutes for highly polished rice and knowing when to stop the soaking is called gentei kyusui.
• The next step is the steaming of the rice grains in order to change the rigid grain into somethinng softer. The rice is steamed eight times.

The next step in the transformation of rice into sake involves koji which I will leave to another blogpost. Stay tuned!
References:
1. How is Sake Made?
2. Harper, Philip, The Book of Sake A Connoisseur's Guide, Kodansha International, 2006.