Meiji-era wooden vat at a closed brewery brings back the brewery's own yeast

The brewery’s yeast, lost when it closed

Ito Co., Ltd., which makes the sake brand Shikishima, is a sake brewery in Handa, Aichi Prefecture, founded in 1788. The Chita Peninsula, south of Nagoya, was once a sake-producing area that shipped its sake by boat to Edo (present-day Tokyo), and Shikishima was one of the largest breweries in the Chubu region. Falling demand, however, forced it to close in 2000. In 2021, Yu Ito, the ninth-generation head, bought back the land and buildings, which had passed into other hands, and resumed brewing.

The yeast that drives sake fermentation has a major influence on aroma and flavour. Today many breweries use “kyokai yeast”, distributed by the Brewing Society of Japan, or yeasts developed by individual prefectures. Shikishima, by contrast, used to cultivate its own yeast in-house, but this was lost when the brewery closed. In the yeast column of old production records found in the former brewery, Ito noticed an unfamiliar code beginning with “SK”, and so learned that the brewery had once had a yeast of its own.

Seven strains found in the wooden vats

The project got going after Ito was reunited with Professor Masashi Kato of the Applied Microbiology Laboratory in the Faculty of Agriculture at Meijo University. In December 2024, students from the laboratory entered the old main brewery, where no sake had been made for more than 20 years, and collected samples from wooden vats dating back to the Meiji era. Yeast dies easily when it dries out, so the chances of survival were thought to be slim. Professor Kato himself reportedly put the odds of success at fifty-fifty.

In February 2025, seven strains of “yeast-like microbes” were picked out from the culture medium. Genetic analysis showed that, although they belong to Saccharomyces cerevisiae, the same species as sake yeast, they are different strains from kyokai yeast. In November that year, a trial brew at a public research institution in Aichi Prefecture produced a sake that tolerates alcohol well, with a banana-like aroma and a melon-like umami.

Towards a sake that lets you taste the brewery’s history

The yeast was also used for trial brewing at the brewery itself, and the sake went on trial sale at a local event in April 2026. It is one bottle in a joint project in which local rice farmers and three Aichi breweries each make a sake from the same sake rice, Yumeginga. The brewery plans to develop the sake made with this yeast into its flagship product. Ito cites passing on old brewery buildings, now rare in Japan, to future generations as a major reason for reviving sake brewing.

It may be some time before this sake reaches Europe. Even so, the point of interest is clear. As with the “native yeasts” of wine and beer, yeast is a major source of character in sake too. If the yeast’s name and origin can be checked on the bottle’s description or in an importer’s materials, it could offer a way to think about how the aroma differs from sake made with kyokai yeast.