At Asahi Shuzo, we only make one sake: Dassai. From all the different categories of sake, Dassai is of the most premium "Junmai-Daiginjo" category. Junmai means it is naturally fermented, without any alcohol added. Additionally the word Daiginjo is very important: it describes top-quality sake that is made using rice that has been polished to remove at least the outer 50% of the original rice grain.
The Dassai brand is becoming widely known not only among sake enthusiast and foodies, but also among the general public. The product that triggered its popularity was Dassai 23. The "23" in the name is derived from the fact that this sake is made from rice that has been polished to 23% of its original grain size. When sake is crafted using highly polished rice (at least half of its original size), it can be labeled as the highest grade: Daiginjo. To create Dassai 23, the rice is polished to remove 77% of its outer surface until only a tiny core of the rice remains.
Another production process essential to the flavor of Dassai is washing and soaking the rice. To understand how important the washing process is, consider the mechanism of sake crafting. Unlike malt for beer, rice for sake does not contain the amylase necessary for converting starch to sugar. The starch must first be converted into glucose with the help of koji, a mold known technically as aspergillus oryzae. The glucose and yeast are then combined to initiate fermentation that converts sugars into alcohol.
In a quiet room, men walk around slowly, shaking containers. Some may think this is some kind of religious ceremony or may find these movements humorous. In fact, these men are engaged in a rice malt-making process in which they sprinkle koji mold over steamed rice so that rice malt can develop.
In chilly a room where the temperature is maintained at 5°C temperature, when the lid of a fermenting tank is removed, a fruity aroma fills the space. Although there are many varieties of fruity aromas, this particular scent suggests a fresh green apple.