Kōji no kaori

Kōji aroma(s)

During sei-kiku, koji gives off various smells, described with particular expressions. As they arise at distinct stages of the koji-making process, they are used to assess both its progress and koji quality.


Normal / pleasant aromas

(1) Steamed rice smell (jo-mai-ka, 蒸米香).

The smell of steamed rice; this disappears as koji making proceeds.

(2) Moyashi-ka (もやし香).

The smell of moyashi (seed koji).

(3) Kuri-ka (栗香, chestnut smell).

A smell like roasted chestnuts that occurs before de-koji, the end of the koji-making process. Also called kuri-mi (栗味; Literally, “chestnut taste”) . This aroma often occurs when the koji has grown well into the centre of the rice grains, and so koji with kuri-ka is held to be good koji.

(4) O-haguro-shu (long second “u”, おはぐろ臭; ferrous acetate smell. Literally, “tooth-black smell”).

There used to be a custom in Japan of blackening the teeth, and the liquid used for that purpose was called o-haguro, and had a similar odour.

(5) Kinoko-shu (long “u” キノコ臭; mushroom smell).

A mushroom-like odour.


Unpleasant smells

(6)  Shikke-shu (long “u”, 湿気臭; “damp smell”).

A mouldy smell occurring when there is too much damp.

(7)  Netsu-ka (熱香; “heat smell”).

A smell arising when the temperature gets too high during sei-kiku.

(8)  Hineka (老ね香; “old smell“).

A smell detected when koji is left in the koji-muro too long.