Rice koji

Koji de riz

What it is

Aspergillus oryzae was named Japan's national fungus in 2006: sake, miso, shoyu, mirin and amazake all begin with rice it has grown through. The spores are not made by the brewers but bought from a handful of seed-mould houses, some of them centuries old, which supply the whole country.

In the kitchen

Its amylase dies above roughly 60°C, so amazake is held at 55–60 for six to eight hours and never simmered. Fresh koji keeps a week chilled and freezes well; dried wants an hour's soak before it does anything at all.

Goes with

Rice Soybean Salt Shio-koji Hon-mirin Sake kasu

Same species

Barley koji Black koji Shio-koji Koji spores (tane-koji)

Also used with

Bettarazuke Iburigakko Mugi miso

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