Tokubetsu junmai ("special pure") is a special designation for high-quality sake. To qualify as tokubetsu junmai, a sake must be made with rice polished to less than 60 percent of its original weight, and must not be fortified with distilled alcohol. Many believe that there is little difference between Tokubetsu and Daiginjo sake, only that the former is more expensive due to the extra special care during the brewing process.
The rice used to produce all special-designation sakes must be polished to a legally defined degree to remove the bran and improve taste. At least 15 percent of the rice used in these sakes must also be affected by koji-kin, a filamental fungus that helps to break down starches into sugar. Koji (Aspergillus oryzae) is also used in the production of other fermented food products, including soy sauce, mirin and miso paste (the base ingredient of miso soup).
