Komaishushu (old-rice sake aroma)

Komaishushu (古米酒臭) refers to the aroma characteristic of sake brewed with old rice. This aroma can become stronger as the sake ages. It is thought to be caused mainly by a compound called dimethyl sulfide, which is considered the source of its distinctive character. In some cases the aroma is accepted as part of the flavor of aged sake, but when it is perceived as excessive, it can affect quality. When enjoying sake, it is worth paying attention to differences in aroma such as this.