How to make Rice Koji by Takehito. Posted on 07/04/2015 07 Apr How to make Rice Koji Print Recipe Rice koji is one of the most important ingredients in miso paste. Koji is a type of fungus that helps fermentation. Prep Time 3 days Prep Time 3 days How to make Rice Koji Print Recipe Rice koji is one of the most important ingredients in miso paste. Koji is a type of fungus that helps fermentation. Prep Time 3 days Prep Time 3 days Ingredients 12 kg White Rice to make 14kg of Rice Koji 1 tbsp Koji mould Servings: Share this Recipe Powered byWP Ultimate Recipe Dashi Stock Tonjiru (Pork & Veggies Miso Soup)