Space-inspired 'vacuum sake' server aims to protect unpasteurised sake on its way to the world

Three companies, including the Tokyo IT firm Plat’Home, have developed a “vacuum sake” server that keeps sake away from the air, with the cooperation of a sake brewery in Akita Prefecture. Akita lies on the Sea of Japan side of northern Honshu and is a region known for rice farming and sake brewing. The development team has been running field trials for three years, and is reportedly aiming to establish a technology that preserves the freshness of unpasteurised sake (namazake), which has not been heat-treated. The goal is to deliver the taste of sake fresh from the brewery, just as it is, to people around the world.

A non-return valve born from rocket hydraulics

The server is used by fitting a 5-litre vacuum pack inside a refrigerator. The key component is a silicone non-return valve attached to the pack. Inspired by the hydraulic equipment of space rockets, it lets liquid flow in one direction only, so that outside air is unlikely to get into the pack as the sake is poured. Because the sake is stored in a state where it has little contact with oxygen, the developers explain that its freshly made aroma and colour can be kept for longer.

Why unpasteurised sake is hard to transport

Most sake undergoes heat sterilisation known as “hiire” before shipping, which keeps its quality stable. Namazake, which skips this step, is prized for its fruit-like, juicy aroma and a faint sparkle. On the other hand, it is vulnerable to changes in temperature and to oxidation, and its flavour changes quickly once opened. For this reason, even within Japan it is often drunk in regions close to the brewery, and it has been considered unsuited to export, which requires long transport. Cutting off the air with a vacuum pack rather than a bottle could be one answer to this problem. If the technology is put to practical use, it may also become easier for restaurants to serve an opened namazake over several days.

Finding namazake in Europe

It has not yet been announced when, or in which countries, the server will start to be used. Even so, efforts to bring namazake overseas with its brewery taste intact are a trend worth watching. When looking for namazake in Europe, it helps to look for the terms “Namazake” or “unpasteurised” on labels and menus. As a rule, keep it in the fridge once bought and finish it soon after opening. Pour it into a wine glass, which lets the aroma open up, and you can also enjoy how the taste changes as a well-chilled sake gradually warms. It will also be interesting to see whether a sake bar or restaurant eventually appears that pours “brewery-fresh namazake” like draught beer.