What is Koji (麹) to Japanese?
Ancient wisdom of preserving food descended from 2,000 years ago.
Knowledge to utilize koji 麹 ('qu' in Chinese) cultivated molds or fungi from boiled grains had been developed in Asian countries, while yiest (kobo酵母) or maltz (bakuga麦芽) grown from fruits or wheat in the West.
koji (Aspergillus oryzae) grown by cultivating molds on boiled grains, produces various enzyme, such as amylases, proteases, and it is very versatile, used for multiple purposes and consists of the basis of Japanese cuisine "washoku".
There are three types of koji, kome 米 koji (rice koji), mugi 麦 koji (wheat koji) and mame 豆 koji (bean koji) .
Rice koji is used for brewing sake 酒, 'amaze' 甘酒(fermented rice poriage) and 'miso' 味噌(fermented soy paste, 'jiang 醤' in Chinese), wheat koji is mainly for making 'shoyu' 醤油 soy source and bean koji is for making 'natto' 納豆(soy nuggets).
koji for making soy source
rice ball koji in south-east asia
Red rice mold used for making red rice wine and tofu-you
How to make koji?
major source for introducing japanese brewing in foreign languages are as follows.
R.W. Atkinson "brewing in Japan" published in 1878
Korshelt "über sake dass alkoholische vertrank der japaner" in 1985
the step is simple; soak and steam rice, inoculate and incubate tane koji 種麹 (starter).
It is also possible to cultivate starter from rice grain in the paddy fields, but nowadays, usually bought from tane koji factory.
molded ice grain 'inadama稲玉' is inoculated in boiled rice
Making koji is something like baby-sitting
Keeping temperature is very important when making koji; 32-36 degree Celsius.
lower than that, enzyme of koji will be deactivated, and when higher than that, it will also be dying.
It takes around 3 days to be ready, and needs to be paid attention every 4 hours. It needs to make warmer, or cooler when heated too much.
Step by Step...
1. mushi 蒸し, boiling rice
The first step is the most important above all, said a touji (brewer),
2. tane kiri 種切 and tsutsumikomi 包込, rolling
Inoculate starter, tane koji
The following morning, koji is penetrating the rice.
3 days later....
3.karashi 枯らし, drying koji
This is the last moment of fermentation process.
make ditch on koji, shaped spiral, three lines, or wavy line to dry it up.
the shape of the ditch depends on the brewery, said a brewer, showing us beautifully drown ditch on koji, which seemed like 'karesansui枯山水', dry garden in zen temple, the art of fermentation!.
4. shimai 仕舞, dancing koji
Shimai means the end in japanese, and 'mai' also stands for dancing.
spreading white colored koji mold is something like dancing, indeed.