What term refers to the fermenting mash used in sake production?

The term that refers to the fermenting mash used in sake production is "moromi." During the sake brewing process, the moromi consists of a mixture of steamed rice, water, koji mold, and yeast. This mash is where the fermentation takes place, leading to the conversion of starches from the rice into sugars and then into alcohol.

Understanding this term is crucial for anyone studying sake production, as it represents a key stage in the brewing process. The moromi is typically monitored closely, as various factors such as temperature, time, and the balance of ingredients can significantly affect the flavor and quality of the final sake product.

The other terms mentioned do have their significance in sake brewing but do not refer directly to the fermenting mash. "Nakakumi" refers to the intermediate stage of the mash before it fully ferments, "Nada" refers to a region known for sake production, and "Muroka" is a term describing sake that has not been filtered. Each term plays a role in the overall sake production process, but "moromi" specifically identifies the active fermentation stage.