Seed (starter) kōji; moyashi

Made by mixing wood ash into steamed white rice which has been only slightly polished, and propagating koji -kin (Aspergillus oryzae) while controlling the temperature of the mixture, room temperature and humidity level until a plentiful quantity of spores has grown. At this point, it is dried, and can then be used as a starter when making koji during brewing. In the brewing industry, it is also called moyashi (which in lay Japanese refers to beansprouts).

After de-koji, the product (simply dried to around five percent moisture) is called “grain form” ryujo (粒状, long “u”, long “o”) tane koji . When used, it is passed through a fine sieve to separate the spores, and sprinkled on steamed rice.

When only the spores are collected from the original grain form, the resulting product is called powder (fun-jo (粉状, long “o”)) tane koji . It is common when using the powdered form to use it mixed with gelatinized starch to add bulk. In contemporary brewing, the increased volume of sei-kiku and improvements in equipment for sprinkling the powder mean have made use of the powder form the standard.


tane koji moyashi grain

tane koji moyashi grain (Picture courtesy of Higuchi Matsunosuke Shoten Co.Ltd)

tane koji moyashi powder

tane koji moyashi powder (Picture courtesy of Higuchi Matsunosuke Shoten Co.Ltd)