Dassai and Mitsubishi Heavy Industries Successfully Ferment Sake in Space
Dassai and Mitsubishi Heavy Industries fermented sake mash on the ISS under simulated lunar gravity and finished it as sake on Earth.
On 28 April 2026, Dassai Co., Ltd., the brewer of the sake Dassai, headquartered in Yamaguchi Prefecture at the western tip of Honshu, and Mitsubishi Heavy Industries, Ltd. announced that they had completed the first mission of the “Dassai MOON Project”. The project aims to brew sake on the Moon in the future. The two companies sent a jointly developed brewing apparatus and ingredients to Kibo, Japan’s experiment module on the International Space Station (ISS). Inside a Japan Aerospace Exploration Agency (JAXA) experiment device, they recreated gravity equivalent to that on the lunar surface and fermented the mash for about two weeks. Dassai says it is the first in human history to succeed in a sake-brewing test in space.
Sake ferments even in lunar gravity
Sake is made by fermenting “moromi”, a mash of steamed rice, koji (rice on which koji mould has been grown), yeast and water. When the mash returned from space was examined on the ground, its alcohol content had reached 12%. The experiment confirmed that alcoholic fermentation proceeds even under lunar gravity. However, the data recorded in space showed that fermentation progressed more slowly than on the ground. Gravity may affect the speed of fermentation, and further research is planned. The apparatus developed by Mitsubishi Heavy Industries stirred the mash while sensors measured temperature and alcohol concentration, and it operated as planned.
Just 116 ml of “space sake”
The mash arrived at the brewery at the company’s headquarters in Iwakuni, Yamaguchi Prefecture, in March 2026. Pressing about 260 g of mash produced 116 ml of refined sake, “Dassai MOON – Space Brewing –”. Of this, 100 ml was bottled in a titanium bottle as proof of the challenge and sold for 110 million yen (tax included). The proceeds are to be donated to Japan’s space development. The sake lees left after pressing will be analysed in detail by a laboratory at Tohoku University, in order to examine how the yeast’s genes changed in space and how it differs from fermented foods made on the ground. The mission used Japan’s H3 rocket and the new HTV-X1 cargo spacecraft, and the work in space was carried out by Japanese astronaut Yui Kimiya. The mission logo was drawn by Koyama Chuya, creator of the space-themed manga “Uchu Kyodai” (Space Brothers).
For European readers: what to watch
You are unlikely ever to get the chance to drink sake brewed in space. Even so, Dassai is a brand often found in specialist sake shops and restaurants in Europe. The brewery focuses on “junmai daiginjo”, the top grade, made by milling the rice down heavily before brewing. Lightly chilled and poured into a wine glass, its fruity aroma comes through clearly. While savouring a glass, it is interesting to consider how slower fermentation might affect flavour. The slower fermentation seen in space leads directly to that very question. Two things to watch from here are the results of Tohoku University’s analysis of the sake lees and the next stage: building a sake brewery on the Moon.
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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