【Reading】こくもつず

【English Name】Grain Vinegar

An indispensable presence when sushi restaurants prepare their shari (vinegared rice)—kokumotsu-su (grain vinegar). It is a vinegar brewed from multiple grains such as rice, wheat, and corn, and under the definition of the Japanese Agricultural Standards (JAS), the name applies to vinegars made using 40 g or more of grain per liter.

Usage varies by establishment; in some cases shari is prepared with grain vinegar alone, while many artisans blend it with red vinegar (akasu) or rice vinegar (komezu) to explore their own proportions. Among commercially available sushi vinegar products as well, the majority are items in which grain vinegar holds the position of main ingredient.

In terms of flavor, it has a sharper acidity than rice vinegar, accompanied by a soft, grain-derived depth. The technique of blending multiple ingredients such as rice, wheat, sake lees, and corn during the brewing stage is widely adopted, and the diverse ingredients give rise to a breadth of flavor.

In terms of method, it follows a two-stage process in which the carbohydrates of the grain are first subjected to alcoholic fermentation and then advanced to acetic-acid fermentation. Beyond seasoning, it also has sterilizing effects and prevents discoloration of ingredients, making it a dependable seasoning across various aspects of cooking.