"Shikishima," the revived sake brewery of 2021, successfully collects unique sake yeast from a cellar over 150 years old!

It is with great pleasure that Ito Corporation (Headquarters: Kamezaki-cho, Handa-shi, Aichi Prefecture; Representative Director: Yu Ito), a 100% subsidiary of Kamezaki Kamos Co., Ltd., announces the successful collection and trial brewing of unique yeast from its main brewery, which had been closed for over 20 years. This will be released as part of the KT Project at the Kamezaki Sake Festival on April 11th.

Holding the bucket from which yeast was collected, in front of the Meijo University Faculty of Agriculture, Department of Applied Microbiology.

What is Sake Yeast?

Sake yeast is the microorganism responsible for alcohol fermentation in sake production. It is a type of "Saccharomyces cerevisiae." The specific type of sake yeast significantly impacts the taste and aroma of the sake. Currently, it is common practice to use "Kyoho yeast" distributed by the Japan Brewing Society or yeasts developed by each prefecture.

Why Did We Decide to Collect Our Own Yeast? - The Story Behind Yeast Collection

The Ito Goshi Kaisha, which used to produce Shikishima, went out of business once in Heisei 12 (2000). Upon its revival in 2021, the 9th-generation director, Yu Ito, bought back the land and buildings that had been transferred to others. Currently, sake is being produced at the brewery adjacent to the former main brewery. The former Ito Goshi Kaisha was once renowned as one of the largest sake breweries in the Chubu region and cultivated its own proprietary yeast. However, this yeast was lost when the company ceased operations.

While looking through past brewing records unearthed from the old main brewery, the 9th-generation director Yu Ito found the characters "SK-1" and "SK-2" in the yeast section. This was undeniable proof that they once possessed their own unique yeast. A brewery miraculously revived through a series of events, brewing sake using sake yeast remaining in a cellar over 150 years old—how wonderful would that be? The 9th-generation director Yu Ito dreamed of this romance.

This is a yeast called "SK-N"

However, it is not difficult to imagine that the possibility of yeast surviving in a brewery closed for over 20 years is extremely low, as sake yeast dies without moisture. Furthermore, for the first few years after the revival, they were preoccupied with immediate tasks and lacked the capacity to pursue this endeavor.

During this period, an encounter with Professor Kato from the Department of Applied Microbiology at Meijo University, whom he met at an event, became a catalyst. With the diligent efforts of the students in his laboratory, yeast collection took place in December 2024. On the day of collection, the students searched the main brewery, where no sake had been brewed for over 20 years. "The possibility of yeast remaining is extremely low"—yet, there was a sense of premonition.