- Year-round brewing (literally, “four-season-brewing”)
At hot times of the year, if brewing is carried out without cooling equipment, the temperature of the mash gets too high, and becomes too dry and acidic, so that it is difficult to make good quality sake. For that reason, the sake brewing season was traditionally concentrated in the winter. In the modern era, increasing shortfalls of seasonal manpower occurred, and the ongoing mechanization of brewing processes made it desirable to increase the utilization rate and productivity of new equipment. These factors led to the introduction of year-round brewing after about 1960. For year-round production to be possible, it is necessary achieve low temperatures (7-8°C) by use of refrigeration and so on. The system came into full-scale use after about 1960.