Sake & brews ── Nihonshu (sake)

Koshu

Koshu — long-aged sake

Sake held back and aged in the brewery beyond its production year before release. A research group on aged sake defines it as unsweetened sake matured at least three full years, and the longer it rests, the darker its color and the more its aroma is said to shift toward brown sugar or honey.

What it's made of

In contrast to shinshu, sake released within its production year, sake held back for extra years before shipping is called jukuseishu or koshu. A research group on aged sake defines 'matured koshu' as unsweetened sake aged at least three full years at the brewery. The longer it ages, the more its color is said to shift — from a pale yellow-green, through amber, toward a deep reddish brown.

How it's made

There's no special added process — aging simply means holding the pressed sake in the brewery under careful temperature control for an extended stretch. As it ages, the aroma is said to drift from something like brown sugar toward honey and then caramel, and bottles aged past a century are sometimes called 'great koshu.'

Why it took this shape

Sake has traditionally been drunk fresh, as shinshu not long off the press, and a culture of deliberate long aging is said never to have taken root as deeply here as it has for wine or aged awamori. It's only in recent years, as a research group worked out clearer definitions and categories, that koshu is said to have drawn renewed attention as a way of savoring time itself.