Rice alcohol is sometimes called rice “wine” or “beer.” Nihonshus are sake pointing to its Japanese source, but to be more precise, it refers to seishu (clear sake). In Japan, the generic term “nihonshu” (literally “Japanese alcohol”) is preferred to describe this popular beverage, whose methods of manufacturing have been perfected and diversified over the years. To grasp the immense variety of sakes, one needs to understand the steps in its manufacture.
The choice of rice and its polishing determine the quality of the final product. If the surface layer, containing little aroma of the rice, has been polished by 50%, the end result is a daiginjo. If 40% of the rice grain has been milled away (i.e. a polishing rate of 60%), this is a ginjo. These two classes are for premium sakes. A junmai is a sake designed only with water, koji mold (minimum of 15%), and yeast. Ordinary sake, futsushu, accounts for the majority of production. This is everyday sake that has been fortified with alcohol; it is enjoyed warm or at room temperature.
Once the rice is polished, it is soaked, washed, steamed, boiled, and a part of it is then separated and sprinkled with koji mold. This variety of fungus rapidly converts the starch in the rice to sugar, allowing for future fermentation. When it comes into contact with a lactic ferment,
the koji mold and its rice form shubo. Putting it into vats is done in steps. The rest of the rice is mixed methodically with the shubo and source water, which gives nihonshu its texture. Fermentation lasts between three and five weeks and it is assessed by the Toji, the chief brewer.
At the end of this step, when alcohol is added to a preparation made with a polishing rate of at least 70%, the result will be a honjozo. This is a drier sake, with more aromas, and the rice flavors are more delicate. The sakes are kept in the vats for some six months. If it has a milky appearance, it is not filtered and becomes known as nigori. Chilled, lightly sweetened, and sometimes sparkling, this dry sake has a more marked weight when savored in the mouth. Thanks to advances in filtration techniques, it tastes like a clear namazake. It is appreciated for its chilled yet harsh taste, hints of umami, and slightly zesty texture.
Some sakes can be aged for several years. They assume a more amber color and develop a bitterness, with aromas of dried fruits or mushrooms. These are referred to as taruzake if they are matured in cedar casks and koshu if they are at least three years old. A tokubetsu mentions the “special” character of the bottle showcased by its creator.
For an exhaustive list of sake-related terms, refer to the following diagram.