We developed a novel method of brewing low alcohol sake. The process was based on a combination of a restricted supply of glucose in moromi mash and yeast deficient in ability to ferment maltoorigosaccharide. Fermentation of moromi mash by a small koji ratio was carried out with kyokai 1001 yeast. The product had a 9.6% ethanol concentration. Based on these results semiindustrial-scale (total 135 kg of rice) brewing was carried out. The fermentation progressed smoothly and ethanol was produced at a concentration of 12.3%. The sake from this moromi mash contained considerably high amounts of maltoorigosaccharide. No diacetyl odor was found in this product even after storage for 6 months at 5°C.