What the Imai Sake Brewery Main Storehouse Is
The Imai Sake Brewery Main Storehouse (今井酒造店本蔵, Imai Shuzōten Honkura) in Toriyama-nakachō, Ota City, Gunma Prefecture, is a two-story Dozo-zukuri earthen-walled brewhouse built in 1908, and it became a Registered Tangible Cultural Property on August 1, 2016.
It sits toward the northwest of the brewery grounds, joined to the New Storehouse on its north and to the Boiler Room and Bottling Room on its east. It measures 12 by 5 ken (1 ken is about 1.8 meters) with a building area of 254 square meters, or about 77 tsubo in Ota City's figures.
Where the Starter and the Mash Were Made
The storehouse was registered for contributing to the historic landscape. The Agency for Cultural Affairs describes the Imai Sake Brewery Main Storehouse as a large earthen storehouse that carried the core of the brewing, including the shubo and the moromi.
Shubo, the yeast starter, is a small batch of steamed rice, koji and water in which yeast is allowed to multiply. More rice, koji and water are then added to it in stages and left to ferment into moromi, the mash, which is finally pressed to separate sake from the lees. Ota City says the Main and New Storehouses between them handled every step from cooling the steamed rice to storing the pressed sake. The Main Storehouse was the first stop for rice coming out of the steamer next door.
Of the six listed structures at Imai, only these two storehouses sit at the heart of production. The Main Storehouse went up in 1908 and the New Storehouse beside it in 1909, one year apart.
What to Look For
The walls change material halfway up. The lower part is cedar Shitami-itabari, overlapping horizontal boards, and above that the walls are sealed in white Shikkui lime plaster. Lime plaster is easily damaged by rain splashing up from the ground, and boarding the lower section is a common way of protecting storehouse walls. The line where dark timber meets white plaster runs the full length of the building.
Inside, the ground floor is entirely earthen, with no raised flooring at all. Part of the upper floor was never boarded over, so a void opens from the ground up into the roof. The Agency does not say what the void was used for, but it is clear that the Imai Sake Brewery Main Storehouse needed height as well as floor space.
At 12 ken the building runs to more than 20 meters, the longest earthen wall on the site, with the two finishes running along all of it.
Visiting
The interior of the Imai Sake Brewery Main Storehouse is not open, and the Gunma sake brewers' cooperative lists the brewery as not offering tours (checked September 25, 2026).
The contrast between the boarded base and the plastered upper walls is visible from outside. The brewery's website has an exterior photograph of the Main Storehouse, which helps in spotting it once you are on the grounds.
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Q&A
- What was the Imai Sake Brewery Main Storehouse used for?
- Making the yeast starter (shubo) and the fermenting mash (moromi). Together with the New Storehouse it handled everything from cooling the steamed rice to storing the pressed sake.
- How big is the Imai Sake Brewery Main Storehouse?
- It is a two-story earthen-walled building of 12 by 5 ken with a building area of 254 square meters.
- What are the walls of the Imai Sake Brewery Main Storehouse made of?
- Cedar boarding on the lower section and white lime plaster above it.
- Can visitors go inside the Imai Sake Brewery Main Storehouse?
- No. The interior is not open, and the brewery does not offer tours.
- When was the Imai Sake Brewery Main Storehouse registered as a cultural property?
- On August 1, 2016, as Registered Tangible Cultural Property No. 10-0332.
Basic Information
| Name | Imai Sake Brewery Main Storehouse (今井酒造店本蔵) |
|---|---|
| Location | 746-2 Toriyama Nakacho, Ota City, Gunma Prefecture |
| Designation | Registered Tangible Cultural Property (building), No. 10-0332 |
| Year Designated | Registered August 1, 2016 |
| Quantity | 1 building |
| Dimensions | Two-story dozo-zukuri storehouse, tiled roof, building area 254 square meters |
| Owner | Not listed (the Agency for Cultural Affairs database gives no owner name) |
| Public Access | Interior closed (no brewery tours) |
References
- Agency for Cultural Affairs, Database of National Cultural Properties: Imai Sake Brewery Main Storehouse
- https://kunishitei.bunka.go.jp/heritage/detail/101/00011063
- Ota City: Imai Sake Brewery registered buildings (Japanese)
- https://www.city.ota.gunma.jp/page/4165.html
- Imai Shuzoten official website, Kazekura (Japanese)
- https://www.kaze-kura.com/
- Gunma Sake Brewers Cooperative: Imai Shuzoten (Japanese)
- https://www.gunma-sake.or.jp/kazemakase/index.php
Last verified: 2026.09.24
