To polish rice is to polish the taste of sake (rice polishing/milling).
Fine sake is produced by polishing brown rice to white rice. Removing the outer bran layers eliminates zatsumi, the unfavorable taste of sake. Generally, the more polished the rice, the higher the grade of sake. At Fukukomachi, rice is polished down to 70% of original size to create our Junmai-shu and Hojozo-shu sakes. Our Junmai Ginjo-shu sake is polished down to 55%. Our finest Daiginjyo-shu sake is polished down further to 40% which leaves almost nothing but kernel.
The hands tell the story (rice washing).
After polishing, the nuka, or the paste of bran, is washed away from the polished rice. We at Kimura Brewery have remained faithful to our tradition of the “handmade process” and “kan-zukuri”, or the process of making sake during the winter season using its natural phenomenon. After considering the rice variety, hardness, and polishing rate, we figure how long the rice should be washed. By hand-washing the rice and not depending on machines, even in the cold of winter, we can sense the amount of water absorption of the rice.
Softening by steaming (rice steaming).
The day after the washing, the rice is steamed in a large vat known as the koshiki. Steaming makes the inside of the rice soft to the core but the outside remains firm and dry. This condition is known as sabake. The steamed rice is chilled in severe winter air until it becomes perfectly firm.
The most important process of sake brewing (koji making).
Koji mold is cultivated on steamed rice and vigil is kept for two nights to maintain room temperature of between 95 and 109.4 degrees Fahrenheit, even in midwinter. We watch for temperature change, humidity, and hazekomi conditions (elongating bacterial threads in the steamed rice).
The source of the fermentation process (shubo).
Starter shubo or moto, the fermentation starter, is cultured yeast which is used for the fermentation mash. It needs very high technique to cultivate only the genuine sake yeasts avoiding the others. Only a small number of the more than 100 yeast types are suitable as the refined sake yeasts, in terms of taste and aroma, for sake brewing. Each of the qualifying yeasts have different natures and bring different characters to each product.
Fermentation and the resulting mash (moromi).
Steamed rice, koji, fermentation starter, and water are mixed in a tank. Rice is added in three stages, and the mixture is fermented slowly at a low temperature. By taking advantage of the cold climate in the Tohoku region of Japan, this mash will deliver smooth and delicate flavor with umami flavor to the sake.
At last, the aroma (pressing).
After fermentation, the mash goes through a filter press and is divided into undiluted sake and sake lees. Undiluted sake has a fresh aroma, or koji-bana. The first obtained sake is called arabashiri, the next one is called nakagumi, and the third is seme.
Almost there (second filtration/pasteurization).
After pressing, sake contains sediment and yeast fungus which are then filtered out, and the alcohol content is adjusted. Most of our products are pasteurized at 149 degrees Fahrenheit, which is called hiire for sterilizing off bacteria, inactivating enzymes, and stabilizing the quality of sake.
Aged to match today’s diverse cuisine (aging).
After pasteurization, sake is aged in a cool, dark place for three months to a year until the flavor is rounded out and mellow. With today’s diversity of foods, the aging terms are different to suit various tastes. Traditionally, sake is brewed in winter, aging in spring and summer, and shipped in autumn.