Embarking on a journey into the sake world means coming across a countless number of varietals. From the type of rice used to the final flavour, there’s so much variation across the categories and a type of nihonshu that’s gained traction in recent years is koshu.
Known as aged sake, koshu can be recognised by its distinctive dark colouring and depth of flavour. Although there are no official rules for the category, sake must be aged for a minimum of three years to qualify as koshu.
While considered a niche product today, there was a time where koshu was considered the cream of the crop, signifying its potential to rise to the top of the mountain again. The history of koshu is like the drink itself: intriguing, complex, full of contradictions.
A treasure of the past
In the Edo period, aged sake was a premium product that fetched two to three more times than regular sake. The Honcho Shokkan, a food guide released in 1667 stated “after three to five years, the taste is rice and the smell is wonderful, and that is the best. From six to ten years, the taste becomes thinner and yet richer. The colour darkens and there is a strange aroma. Better than the best!”
There’s no doubt that koshu was valued for its sweet and savoury taste, but all that changed during the Meiji period, where aged sake became a thing of the past. Sake breweries were taxed heavily during this time, meaning that storing and aging alcohol was a tax liability. Breweries sold sake off as soon as possible so they could recoup any losses.
In the eras between WW1 and WW2, Japan faced rice shortages and breweries were forced to make imitation sake. Maturing alcohol simply wasn’t possible and by the time the law changed in 1954 so breweries were only taxed on what they shipped, koshu had been forgotten.
Revitalising the category
In the 1970s and ‘80s, marketers were interested in bringing back koshu, only for the movement to be met with hostility. Koshu had fallen so out of favour that it was associated with ‘old’ and ‘forgotten.’ To change this perception, the name jukusei was introduced, which implied intentional ageing.
Fast forward to the modern day and koshu is going through a renaissance, though production remains small. Brian Aschraft points out in The Japanese Sake Bible that there are less than 30 breweries nationwide in Japan’s Association for Long Term Aged Sake.
This hasn’t stopped breweries such as Sawanotsuru from championing the category and experimenting with different ageing methods. The brand has massive koshu cellars, where sake is matured in enamel tanks.
The traditional way to age sake is in clay pots called kame. While the Sawanotsuru method isn’t historically accurate the enamel tanks allow sake to age in the right way.
More progress is being made through the efforts of the Kyoto-based Tokisake Association, which is made of seven breweries. Tokisake is focused on refining the rules of koshu and elevating it into the same price bracket as high-quality vintage wine.
Under the association’s guidelines, koshu can only be made with rice grown in Japan, the drink needs to be aged for at least ten years and brewers are required to keep records of production.
Koshu has all the qualities and heritage to be compared to vintage wines or old whiskies. The difference is that people don’t yet know enough about it to truly appreciate the value, which is why aged sake is very affordable. That might not always be the case though so enjoy it while you can!