- 2 pounds polished rice or barley
- 1 teaspoon dispersed koji spores
- Cheesecloth or plastic wrap
- Dehydrator or another precision-controlled device
Don’t rinse the rice or barley. You want the extra starch to stay around. Koji consumes starch—more is better for the fungus. Cook the rice or barley. You want it to be fluffy and the grains to maintain their shape. Cool the cooked rice or barley to 90°. Sprinkle the koji spores once the grain is cooled. Gently toss so that the spores are evenly dispersed.
Set your dehydrator to between 80° and 90°. Place the grain and spore mixture on the dehydrator trays. Cover each tray with thick layers of cheesecloth or plastic wrap. If using plastic wrap, be sure to poke holes in it or to leave the edges of the pan open to allow for air circulation. Insert the trays into the dehydrator.
Using clean hands, gently mix the inoculated grain a few times a day over the next 48–72 hours. After 2–3 days, you’ll have your koji. The rice or barley will have a fuzzy white covering and have an extremely yeasty and sweet floral aroma. At this point, you can dry the koji and freeze it. You can also turn it into amazake, which is sweet koji, or shio, which is salt koji.
For recipes for amazake and shio-koji, visit EdibleCleveland.com.