Amazing Koji Mold World: 01
The basic Japanese diets consist of rice, soybean, barley, salt and koji

Written and illustrated by Misa Ono


Hello everyone in the world! My name is Misa Ono. I am an illustrator and also a rice malt, “Japanese koji” specialist. I would like to introduce you to the interesting and tasty world of microbiota called koji which is used in a lot of cooking in my country, Japan.

In addition to the many international restaurants in Japan, you can often find curry rice, hamburger steak, and gyoza on the tables of Japanese households. We have croissants and coffee for breakfast, pasta and ramen for lunch, and wine, cheese, prosciutto, and pizza for dinner. We think such an international diet is somewhat upscale; however, when we have sashimi with soy and tasty Japanese sake, we say, “Oh, it was so good! I am so glad to be born Japanese!” When we come back from a trip abroad, we say “Oh I am so tired, I want to have rice, miso soup and Japanese pickles!” Even if we have delicious western foods, after eating them for three consecutive days, we crave Japanese foods, especially simple meals like rice, miso soup and Japanese pickle. This simple diet is something necessary for the Japanese.

The Japanese live on rice. Some prefer brown rice, but most people will polish brown rice to remove the bran covering and then cook the white rice.  The remains after polishing brown rice are called “kome nuka” which is rice bran: the outer layers of rice grain. We add salt and water to the bran, ferment it, and pickle vegetables in it. It is called “Nuka-zuke.” Miso is made of soy beans, salt and kome koji, which is fermented malted rice. We also make tofu and abura-age, which is deep fried bean curd, out of soy bean and use them for miso soup or eat them with soy sauce. Soy sauce is made of salt, water, daizu koji and mugi koji which are fermented malted soy bean and barley. As you can see, other than vegetables and fish, the Japanese diet consists mostly of rice, soy, barley, salt and koji. Japanese diet would not be complete without koji.

Koji is a mysterious microbiota that turns the mixture of rice, soy and salt into miso.  It will also turn soy beans, barley and salt into soy sauce.  What is so attractive about koji that it makes Japanese people crave Japanese foods even after eating tasty western food?



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