Provided are: a mochi-koji which retains the complex and deep aromas intrinsic to sakes which use mochi-koji as an ingredient thereof, while not having a noticeable grassy smell； a sake using the mochi-koji as an ingredient thereof； and a method for producing the same. A method for producing a mochi-koji including steps for (1) forming a molded product from the crushed or powdered product of uncooked grain, and water or the water extract from a plant, and (2) maturing by propagating microorganisms on the molded product, the method for producing the mochi-koji being characterized by maturing with the pH of the molded product staying in the range of 2.0-5.5 during the maturing interval, or the pH of the molded article always exceeding 5.5 during the maturing interval, and at a temperature of 10-25°C.提供具有以餅麴為原料的酒原有的複雜且深厚之香味但沒有生澀味的餅麴及以餅麴為原料的酒、和其製造方法。一種餅麴之製造方法，其特徵在於包含下述步驟：(1)自無蒸煮的穀類破碎物或粉狀物、與水或植物性水萃取物形成成形物；(2)藉由使微生物於前述成形物繁殖來進行熟成；且使前述成形物的pH值在熟成期間中維持在2.0~5.5的範圍，或是使前述成形物的pH值在熟成期間中始終超過5.5且在10~25℃之溫度下進行熟成。
