Japanese practice: polished Rice and Low Temperatures

Chinese brewers use rice that has been milled to remove about 10% of the grain, only slightly more than is removed to make ordinary white rice for cooking. In Japan, however, the rice for anything above the standard grade of sake must be milled to remove a minimum of 30% of the grain, and the highest grades of sake are made with rice that has been polished down to 50% or less of its original weight. The center of the rice grain is the portion that contains the most starch and the least protein or oil, so the more the outer layers of the rice are ground away, the simpler and purer the remaining grain, and the less grain flavor it contributes to the final liquid.