Degarashi (resting period for rice, koji, and shubo)

Degarashi (出枯らし) refers to the process in sake production of leaving certain ingredients or intermediate products to rest before they are used, so that they reach a suitable condition. It has three main aspects. 1. Resting of polished rice: Rice that has been polished is left in paper bags or transferred to a hopper and kept there until it is used for brewing. This "polished rice resting period" is intended to even out the moisture distribution within each grain and let the rice adapt to room temperature and humidity. The length of the rest depends on the rice polishing ratio, but it is usually about 7 to 20 days. 2. Resting of koji after removal: After koji is made, it is left for about one day before being used in brewing. This is also called degarashi. During this time, the koji is spread thinly and dried, as a step to improve its quality. 3. Resting of shubo (yeast starter): The period from the division of the shubo (moto-wake, or maru-samashi) until it is actually used in brewing is called the "shubo resting period." Depending on the type of shubo, for sokujo shubo (the quick-fermentation yeast starter) about 5 to 7 days is generally considered appropriate. The degarashi process has a major influence on the overall quality of the sake and plays an important role in shaping its flavor and aroma.