Koji-bacteria release a large amount of enzymes in its process of fermentation.
The enzyme consists of protein.
Although it is an inanimate being, it can compose and decompose substances. The enzymes released by Koji-bacteria bring various gifts to the human body.
Amylase breaks down starch into glucose.
That is why Ama-saké made by Koji is naturally sweet without adding sugar.
Protease breaks down protein into amino acids.
Koji-bacteria produce almost all the amino acids necessary for the human body by breaking down the protein from the surface of rice.
Lipase breaks down fat into fat acid.
In Japan, we gain most of the enzymes used in digestive medicine by cultivating Koji-bacteria.
It is always interesting to learn about good bacteria.
Below are their representatives.
- lactic acid bacteria which produces cheese, yoghurt, etc.
- acetic acid bacteria which produces vinegar
- yeast that produces bread (Saké yeast produces Saké)
- bacillus subtilis natto (Nattō–bacteria) which produces “natto“
- aspergillus oryzae (Koji–bacteria) which produces Koji.
* The name “aspergillus oryzae” was given by one of the German scholars who were invited to Japan by the government at the end of the 19th century.
This bacterium is rarely used outside of Japan.
2. Kanji for Koji
To learn Kanji (Chinese characters) is always interesting and beneficial to understand what the word means.
Through Kanji, we can virtually grasp not only the meaning of the word, but also the background it was born in.
Therefore I’m going to introduce Kanji as often as possible.
Interestingly, there are two Kanji (Chinese characters) that mean Koji: 麹 and 糀.
Firstly, the character 麹.
This Kanji came from China in the 8th century.
You can find 麦 in this Kanji. 麦 means wheat and its reading in Japanese is mu-gi.
In China, wheat is widely used to make Koji.
Basically, this kanji 麹 is used for Koji made from wheat, not from rice.
Secondly, the character 糀.
糀 was born in Japan at the end of the 19th century.
If you take a close look, you can find 米 (rice) and 花 in this character.
As you know, 米 means rice and its reading in Japanese is ko-mé .
On the other hand, 花 means flower and its reading in Japanese is ha-na.
When we combine these two, maybe we can easily imagine one or two stories.
i) when the rice is fermented and becomes Koji, it looks like flowers.
ii) Koji is a flower grown by crystallizing the rice and human wisdom.
I hope these stories indicate the probable process to invent this Kanji.
3. Let’s make Koji
Let me introduce a unique program in Japan.
By participating in it, you can vividly experience the world of Japanese Koji inherited until today.
【Nagano / Saku City】
In this program, you stay at a sake brewery hotel, KURABITO STAY and experience making Koji for amazake.
The Saku area of Nagano prefecture is one of Japan’s leading sake breweries.
There are 13 sake breweries that have been there since the Edo period.
With the cooperation of Kitsukura Shuzo, one of the oldest brewers, you make koji, which is actually sold as a product at one of the brewers.
Through this experience, you can learn about Koji, which is very important in Japanese food culture.
Since ancient times, sake brewing has been considered to be a collaboration with God.
Therefore, at the first step, you clean the sake brewery.
Next, you receive the Shinto ritual from the priest of the Shinto shrine.
Then, you enter the brewery to take part in the workshop.