Komai (old rice)

Komai (古米, "old rice") refers to rice harvested in a previous year, as opposed to rice from the current year's harvest. Because rice in Japan is normally harvested in autumn each year, komai is rice that is at least one year older than the current year's crop. In sake brewing, the use of komai can have several effects. Because komai has a lower moisture content, the fermentation rate of its sugars may increase, but its flavor and aroma also change, so sake made with komai can have a distinctive aged character. However, the quality of komai may have deteriorated, so selecting it carefully is very important when it is used for brewing.