What is Miso?

1. What is Miso?
Miso is a paste-type traditional Japanese seasoning, which is made from soybeans mixed with salt and the fermentation starter known as koji. A koji is produced by rice, barley or soybeans.

2 Miso variations and producing regionFotolia_73670451_XS
Depending on ingredients of koji, Miso is classified into 4 types; Rice-Miso, Barley-Miso, Soybean-Miso and Chogo-Miso.
In Japan, there are more than 1,000+ of miso manufacturers, and almost 80% of them are producing Rice-Miso. Also, miso taste varies by region even among the same type (such as Rice-Miso) depending on climate and fermentation process. But all of them is fermented using koji.


  • Rice-Miso (a.k.a Kome miso) uses rice koji for fermantation by mixing with soybeans and salt. Flavor and color vary depending on koji/salt content. For flavor, there are sweet, semi-spicy and spicy types. For color, there are red, white and light-colored types. Rice-Miso is mainly produced in east and north region in Japan, and major miso brands are Sendai-miso, Aizu-miso, Edo-miso, Shinshu-miso, Tsugaru-miso, Akita-miso, Echigo-miso and Kaga-miso.
  • Barley-Miso (a.k.a Mugi miso uses barley koji for fermantation by mixing with soybeans and salt. It has sweet barley flavor and reddish in color. It is mainly produced in west and south region in Japan.
  • Soybean-Miso (a.k.a Mame miso) uses soy koji for fermantation by mixing with mashed soybeans. As Soybean-Miso has no grain added, it takes longer to ferment. The most popular Soybean-Miso brand is Hatcho miso, which is produced in Aichi prefecture. Soybean-Miso is dark brown in color and has a strong taste and “umami”.
  • Chogo-Miso is compound miso, made from a mixture of any of the above.

3. Health benefits of Miso
All kinds of miso including Rice-miso, Barley-miso and Soybean-miso are using soybeans as a prime ingredient, with rich nutritions such as protein, vitamine and mineral. In addition, the miso’s fermantation process accelerates such nutrient absorption and enhance the nutritional value.

Miso nutrients and expected health effects

  • Protein: lower blood cholesterol
  • Vitamin B12: Help blood formation, reduce mental fatigue
  • Vitamin E: Anti aging
  • Enzyme: Help digestion
  • Isoflavone: Deoxidization , Alleviate stiff neck and sholders
  • Choline: Anti aging, Prevent fatty liver
  • Lecithin: Lower blood cholesterol, Prevent senile deterioration


“日本の伝統食” (in Japanese), グルメ文庫編集部 (2005) , ISBN:978-4758431842
“健康食みそ” (in Japanese) , Hisao Nagayama (1983), ISBN:978-4540830341
Edward R.(Ted) Farnworth (2008),”Handbook of Fermented Functional Foods, Second Edition” p327, ISBN:978-1420053265