Over two hundred kinds of rice exist, but only a handful are certified in Japan as being best-suited for brewing sake. Takashimizu uses only locally grown, certified rice in the production of its products.

As important as the type of rice is the rice-polishing ratio (or "seimai-buai"). The outer layers of the rice grain contain unwanted fat and proteins, and are thereby polished off to reveal the pure starch core. The more highly-milled the rice, the more delicate and aromatic the sake.

The shimizu-no-mai sakes are all polished to 55% or less of their original size, leaving only the best part of the grain. Takashimizu is also the only brewery in Akita with its own rice-polishing facilities, a luxury that allows the brewmasters to guarantee that the local rice is milled to their exacting standards.