In order to make wheat miso, I am making wheat koji first.
Whole Hard Wheat 小麥 500g
Mugi Koji Starter 麥麴菌 1g
* The ratio of wheat and mugi koji starter is 〔1000 : 1〕 or 〔1000 : 2〕。
Soak wheat for 2~3 hours.
Steam wheat 1 hour until it's cooked. Set it aside to cool to 35C.
Measure 1g of mugi koji starter.
Spread the mugi koji starter evenly on cooked wheat, mix well.
Place the inoculated wheat in koji tray evenly.
Place koji tray in the oven with the light on and the door cracked open by a kitchen towel (the temperature is 31.5c when the light is on). I also cover the koji tray with a damp cheesecloth for maintaining the moisture inside of the oven.
The wheat has been incubating for 2 days at 28C. It's covered by light yellowish green furry mold.
Place the try beside heat vent overnight to dry up the wheat. Double check the dryness of mugi koji. Make sure no trace of moisture in order to prevent bad mold growing. Place dried mugi koji in a plastic bag and store it in cool and dry place without direct sunlight. Use it within six months.