Daishichi's shiboritate "Yukishibori Honjozo Namagenshu" is indeed both unpasteurized and undiluted (alc. 18%). It is premium sake of the honjozo type. Typically, a limited amount of brewer's alcohol is added to honjozo to make the taste lighter. But Daishichi wouldn't be Daishichi if it didn't pay extra care: Daishichi's brewer's alcohol is made from rice and not from sugar cane as is normally the case, with the idea that rice should be the one and only ingredient of sake.
Yukishibori has of course been made with the kimoto method (Daishichi is Japan's No. 1 Kimoto brewer), which means it is sake with a rich taste and with "body." Together with the youth of the shiboritate type of sake, that creates a unique combination: first you taste the fresh acidity of the newly pressed sake, and next the deep umami and richness typical of kimoto sake.
The name “Yukishibori” means “Pressed in the Snow,” and is meant to conjure up the image of a sake brewery in a snowy landscape in Northern Japan (the Tohoku region where Daishichi is located): while the sake is being pressed inside the brewery, outside the snow is falling heavy and thick.
Yukishibori Honjozo Namagenshu was first brought to market by Daishichi in 1992, the 240th anniversary of the brewery (which was founded in 1752). Normally, Kimoto sake is matured for a long time (and the fact that it is ideally suitable for maturation is one of its important characteristics, as we will see in this series), so it is interesting to find it here in the shape of such a fresh and young sake - which is also quite a technical feat.
Yukishibori is only sold in winter. The ideal serving temperature is 10 degrees C. Drink it on its own, as an aperitif, or pair it with fresh seafood, sashimi, seafood salads, or raw oysters, in general with foods which have a fresh taste but which also possess a powerful umami. This sake should at all times be kept in the refrigerator and the opened bottle should be consumed as soon as possible.
(Yukishibori Honjozo Namagenshu is only available in Japan)
Disclosure: the blog author Ad Blankestijn works for the Daishichi Sake Brewery. He is also an accredited sake sommelier and sake instructor.