Miso is a condiment peculiar to Japan, produced through fermentation of soybeans and rice. The prototype condiment of miso was brought from ancient China. Since then, Japan developed it into a unique fermented condiment for over 1,000 years. Miso is a precious source of nutrition, and, has always been an important food indispensable in Japanese dining of any era as a condiment for a soup to have with the staple food. The present merits of Japanese cuisine are widely acknowledged worldwide due to it having been registered as one of the world’s intangible cultural heritages, and miso is attracting attention as an extremely important condiment responsible for the “soup” in the traditional Japanese meal serving style “one soup and three side dishes”.

Koji is steamed grains to which koji-mold (aspergillus) is inoculated and grown. When koji is made from rice it becomes “rice koji”, from barley “barley koji”, from soybeans “soybean koji”, and so on. Marukome uses “rice koji” for its miso products. Various enzymes are produced during the process of koji-mold growth on rice. These enzymes decompose starch in rice and proteins in soybeans, resulting in the delicious taste unique to miso.
Brewed condiments such as miso, soy sauce, sake, mirin and vinegar are the basis of Japanese cuisine, and they are not available without koji. It is no exaggeration to say that it is the “power of koji” that has sustained Japan’s unique food culture.