Kōbo jikomi

Sake mashing using cultivated yeast (without yeast starter)

The system of mashing which uses pure yeast cultures (in liquid, “muddy” or solid compressed form) and lactic acid in place of shubo (yeast starter) at the first stage of mashing is known as kobo-jikomi (literally, “yeast mashing”). As far as moromi mashing is concerned, if there are sufficient concentrations of yeast and lactic acid, yeast starter is not an absolute necessity.

Standard procedure is to mash the first soe stage at 14-16℃, using 400-600g of pressed yeast (in solid but not dehydrated form) per 1000kg of total white rice for the batch, and 300-500ml of lactic acid per 100l of mashing water. Procedure thereafter is the same as when using yeast starter in the conventional way. It is sometimes necessary to extend the odori rest day for an additional twenty-four hours. The use of this method allows considerable savings of time and labour as it is not necessary to make yeast starter. As there is no great difference in quality, it has been adopted by many breweries in recent years.