noun
rice koji; malted rice
Rice inoculated with Aspergillus oryzae mold, used as a starter for sake, miso, soy sauce, and other fermented foods. Often translated as 'malted rice', though the process uses mold rather than malting.
米麹を使って甘酒を作ります。
I make amazake using rice koji.
この味噌は米麹から作られています。
This miso is made from rice koji.
Compound of 米 (こめ, 'rice') and 麹 (こうじ, 'koji mold').