Six Months in a Power Station Tunnel: 240 Bottles of Hyogo Junmai Sake Mature Underground
240 bottles of junmai sake from two local breweries, aged for about six months in a tunnel at a Kansai Electric Power pumped-storage plant in Asago, Hyogo, were released on 1 October.
A pumped-storage power station tunnel as a “cellar”
The setting is Asago (Asagoshi), a city in the Tajima region of northern Hyogo Prefecture. Hyogo, whose capital is Kobe, is a prefecture in western Japan and one of the country’s leading sake-producing areas. Kansai Electric Power’s Okutataragi Power Station in Asago is regarded as one of the largest pumped-storage plants in Japan. Pumped-storage generation works by pumping water up to a high reservoir when electricity is plentiful, then letting it flow back down to generate power when demand rises. This time, sake was matured for about six months inside a tunnel at this power station.
Underground spaces are generally out of reach of sunlight and are little affected by outside temperatures. For sake, which dislikes light and sudden temperature changes, such a place can serve as a natural cellar. It is the same idea as maturing wine in caves or ageing cheese in caves.
Two breweries from Santo, Tajima
The sake stored was junmai from two breweries in the Santo district of Asago, Konotomo Shuzo and Tajime, 240 bottles in all. Junmai is a category of sake made only from rice, rice koji and water, with no added brewer’s alcohol. A release ceremony was held on 1 October, and the bottles, fitted with special labels, were scheduled to go on sale at the breweries’ open day (kurabiraki, an event where a sake brewery opens its doors to the public) on 10 October.
The quantity is very small, so this is essentially a local project. Even so, it is noteworthy that small breweries are using a piece of power infrastructure, a facility unrelated to sake making, as a place for maturation. It is a modest, practical idea: making use of the stable environment of an existing underground space without any capital investment.
How to enjoy it in Europe
These 240 bottles are unlikely to reach Europe, but the pleasure of tasting aged sake is within easy reach. Autumn is the season when sake shops stock hiyaoroshi: sake pressed in winter, rested at the brewery over the summer and shipped in autumn. Also look out for bottles labelled “jukusei” (aged) or “koshu” (old sake). Compared with freshly pressed new sake, they tend to be softer, with rounder texture and more umami. Serve it only slightly cool or at room temperature, not too cold, and pour it into a wine glass to make the changes in aroma easier to notice. It also pairs well with mature hard cheese and mushroom dishes. If you keep sake at home, the basic rule is the same as in this tunnel: store it somewhere dark with little temperature variation.
References and sources
- Kobe Shimbun NEXT, “Aged for six months in a power station tunnel in Asago: 240 bottles of sake released, on sale on the 10th, Konotomo Shuzo and Tajime” https://www.kobe-np.co.jp/news/tajima/202610/0020893217.shtml
Sources
This article was written by The Sake Wire editorial team, summarising the public sources listed above. Images are our own.
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