Hakumai no karashi (resting of polished rice)

Hakumai no karashi (resting of polished rice) refers to the process in which polished rice is left to rest for a set period before it is used to prepare the moromi (fermentation mash). The purpose of this rest is to even out the distribution of moisture within each grain and let the rice adjust to the room temperature and humidity. This resting time is called the "polished rice resting period" (hakumai no karashi kikan), and it is usually set at around 7 to 20 days, depending on the rice polishing ratio. In addition, the process in which rice is left for about one day after being taken out of the koji room (deru koji) and then used for brewing is called "de-karashi." In this case, it is important to spread the rice thinly so that it dries. Furthermore, the process carried out between the division of the shubo (yeast starter) into separate containers (moto-wake) and its actual shipment is called "shubo no karashi" (resting of the yeast starter), and this period is usually around 5 to 7 days. Both the resting of polished rice and the resting of the yeast starter are important steps for improving the quality of sake brewing.