【Reading】こしゅ

【English Name】Aged Sake / Kusu

Koshu is a general term for sake that has been stored and aged over a long period; it is read "koshu" for nihonshu (Japanese sake), and for awamori it is called "kusu" in the Okinawan dialect.

In the case of awamori, koshu is defined by fair-competition regulations as that which has been stored in its entirety for three years or more. Through aging, the sharpness of the alcohol softens, and a deep richness and distinctive fragrance are said to be produced. As a traditional aging method there is "shitsugi," a technique of replenishing the portion drunk from an old sake jar with the next-oldest sake, which makes long-term aging possible while maintaining quality. It is said that in the era of the Ryukyu Kingdom there once existed vintages aged 200 to 300 years, but these were almost entirely lost in the Battle of Okinawa; among those that survive, the roughly 150-year-old sake of Shikina Brewery is well known.

In the case of nihonshu, it can be labeled "koshu" with storage of one year or more, and the Long-Term-Aged Sake Research Society often uses the term to refer to that aged three years or more.

In its connection to sushi, the rounded flavor produced by aging is said to pair well with fatty sushi toppings, and it is sometimes enjoyed as a sake to drink with the meal or after the meal.