Sei-kiku・sei-kiku kōtei

【English】

Kōji making; kōji- making process(es)

【Japanese】

製麹・製麹工程

The process of production of koji for seishu is properly known as sei-kiku (製麹). The various systems used include the classical method using small tray-like futa boxes “tray” koji (futa-koji-ho (long “o”s)), the “box” method (hako-koji-ho), which uses slightly larger boxes than the classical method in order to economize on space and labour, the “bed” method (toko-koji -ho), which dispenses with boxes entirely and sees the entire process carries out on a large bed (toko) , and machine-made koji (kikai-sei-kiku-ho), in which last temperature, humidity and growth condition are all controlled automatically. (The rules of Japanese pronunciation mean that futa and hako become voiced in compound words, so futa becomes koji-buta, and hako becomes koji-bako in compound.)

All the methods share the following common preliminary processes.

Raw material (rice) → rice polishing → soaking → steaming → cooling steamed rice. From this point on, koji making proper begins.

1. Tori-komi (取込み, hiki-komi (引込み))
   Cooled steamed rice is taken into the culture room, and piled up on a flat
   toko table at about 33 – 36°C.
2. Toko-momi (床揉み)
   Three or four hours later, the steamed rice is spread out again, and tane-koji is sprinkled on (tane kiri, 種切り). The temperature after this stage is about 30°C.
3. Kiri-kaeshi (切返し)
   After a further twelve to sixteen hours, the pile is broken down and mixed to even out temperature and moisture content.
4. Mori (盛り)
   This is the process of dividing the batch into small lots into futa trays or boxes (or making a thin layer on a toko bed or machine where such are used) after points of haze have become visible on the grains.
5. Naka-shigoto (first mixing) 仲仕事
   Six to eight hours after mori, when the temperature of the koji has reached about 34 – 36°C, it is mixed well to disperse moisture and promote oxygen supply.
6. Shimai shigoto (second mixing) 仕舞仕事
   Five to seven hours after the first mixing, when the temperature has reached 37 – 40°C, the batch is mixed once more, and spread out to ventilate and cool it. After this stage, the particular batch reaches its highest temperature (saiko ondo (long first ”o”), 最高温度).
7. De-koji 出麹
   The end of the sei-kiku process is decided by appearance, aroma and so on. The finished batch is cooled in the cold air outside the culture room, thereby stopping the growth of the koji -kin. It is usual to take a conditioning period (karashi, 枯らし) and use the finished koji in mashing the following day. If it is used on the same day as de-koji, this is known as de-zukai (出使い). As a process, the action of using the koji in mashing is simply called shiyou (使用), use.