Where the mash is mixed and where it is squeezed

Yamayoshi Shoyu Assakuba oyobi Shikomiba (山吉醤油圧搾場及び仕込場, the pressing house and mash-preparation house of the former Yamayoshi soy sauce brewery), at Imasaka in the Noma district of Shodoshima Town, Kagawa Prefecture, dates from 1888 and was entered on Japan's national register of Tangible Cultural Properties on 9 February 2005.

The entry covers a pair of parallel ridges standing east of the brewery's mash warehouse and running alongside it. The pressing house measures about 18 metres by 10, gabled, roofed today in corrugated slate. The mash-preparation house is smaller, roughly 14 metres by 8, gabled and covered in pantiles, with a lean-to eave carried along its eastern face. Both are single-storey timber structures, and the registered building area for the entry as a whole is 324 square metres.

Together with the mash warehouse, these were the core production buildings of the brewery. Everything a bottle of soy sauce goes through, apart from the year of quiet fermentation, happened under these two roofs.

Two rooms, two stages of the process

The shikomiba is the preparation floor. Steamed soybeans and roasted, cracked wheat are inoculated with koji mould and left to grow into a green-dusted culture, then combined with salt water and transferred into cedar vats. The ratio of brine to solids, the temperature of the room and the timing of the first mixing all shape what the mash will become. This is the moment the brewer has most control over, and after it the work becomes a matter of patience and stirring.

The assakuba is where that patience is cashed in. Mature mash is ladled into long cloth bags, stacked in layers inside a press box, and squeezed slowly under increasing pressure. What runs out is kiage, unheated raw soy sauce. What stays behind is a dry cake of pressed lees. The pressing house is the larger of the two buildings for a straightforward reason: presses are heavy, they need headroom, and the floor around them needs to drain.

Registration was granted under the criterion that the buildings contribute to the historic landscape of the country. The register number is 37-0259, gazetted on 28 February 2005 in the 45th round of registrations. The database records the entry as a single unit even though the explanatory text describes two ridges standing side by side, which is a common convention where paired production buildings were registered as one working assembly.

Roofs that do a job

Both buildings carry a koshi-yane, a small raised monitor set along the ridge with louvres or windows in its sides. Soy sauce production generates a great deal of steam and heat, and a monitor roof lets it rise and escape without opening the walls to weather or to direct sun. The device is old and widespread in Japanese timber industry buildings, appearing on sake breweries, silk filatures and farmhouse kitchens, and it is the ancestor of the sawtooth roofs that later spread across brick and steel factories. Standing in the lane below, the monitors read as a second, narrower building perched on top of the first.

The roofing materials differ between the two ridges, and the difference is worth a second look. The mash-preparation house keeps its sangawara pantiles, the ordinary clay tile of western Japan. The pressing house is covered in corrugated slate, an industrial sheet material that entered Japanese building in the modern period and is likely to represent a later re-roofing rather than the original 1888 covering. Wet, hot rooms are hard on tiles and on the timber beneath them, and roofs over presses tend to be replaced.

The lean-to eave along the east side of the mash-preparation house is another functional detail. It shelters the working strip where materials were carried in and out, and it keeps rain off the wall boards at the point where they take the most traffic.

These buildings are in daily use. Yamayoshi Shoyu closed in 2002, and Shokin Shoyu, a nearby maker with long-standing family ties to the Yamayoshi household, took over the premises and restarted production in them. There is no visitor entrance and no general admission. Shokin Shoyu has accepted cellar visits by prior arrangement on weekdays, so contact the company in advance if you hope to see any interior. The exteriors are visible from the public lane, and photography from the road is not restricted, though the site is private and working areas should not be entered.

Anyone who wants to watch a soy sauce press in action without an appointment can go to the Marukin Soy Sauce Memorial Museum in the same Noma district, open daily from 9:00 to 16:00 for a small charge, where the adjoining pressing plant can be viewed from a second-floor terrace and a hands-on pressing session runs at set times. From Sakate Port the museum is about three minutes by car, from Kusakabe Port about ten and from Tonosho Port about thirty; the Olive Bus Sakate line stops at Marukin-mae.

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Q&A

QWhat are the pressing house and mash-preparation house of Yamayoshi Shoyu used for?
AThe mash-preparation house is where koji culture and salt water are combined and loaded into the fermentation vats. The pressing house is where mature mash is wrapped in cloth and squeezed to release raw soy sauce. They stand east of the mash warehouse and formed the working core of the brewery.
QCan visitors enter the Yamayoshi Shoyu pressing house and mash-preparation house?
ANo. These are production buildings of an operating brewery run by Shokin Shoyu, with no visitor facilities. Cellar visits have been accepted by advance reservation on weekdays, so contact the company beforehand rather than arriving unannounced. Exteriors can be seen from the public lane.
QWhy do the Yamayoshi Shoyu pressing house and mash-preparation house have raised structures on their roofs?
AThose are koshi-yane, monitor roofs built to vent steam and heat. Both buildings carry one along the ridge. Brewing releases a lot of moist warm air, and a monitor lets it escape at the highest point while keeping rain and direct sunlight out of the working space.
QHow old are the Yamayoshi Shoyu pressing house and mash-preparation house?
ABoth date from 1888, the same year as the mash warehouse next to them. The registered building area for the pair is 324 square metres: the pressing house is about 18 by 10 metres, the mash-preparation house about 14 by 8.
QWhere can I see soy sauce being pressed near the Yamayoshi Shoyu buildings?
AThe Marukin Soy Sauce Memorial Museum lies in the same Noma district and opens daily from 9:00 to 16:00 with a small admission charge. Its pressing plant can be viewed from a terrace, and a small hands-on pressing session is offered at set times. The Olive Bus Sakate line stops at Marukin-mae.

Basic Information

NameYamayoshi Shoyu Assakuba oyobi Shikomiba (山吉醤油圧搾場及び仕込場)
Location710 Ko, Imasaka, Noma, Shodoshima Town, Shozu District, Kagawa Prefecture
DesignationRegistered Tangible Cultural Property (Structure), register no. 37-0259
Year DesignatedRegistered 9 February 2005; gazetted 28 February 2005 (45th round)
Quantity1 unit (comprising two adjoining ridges)
DimensionsPressing house approx. 18 m by 10 m, corrugated slate roof; mash-preparation house approx. 14 m by 8 m, pantile roof; combined building area 324 m²
OwnerNot published in the Agency for Cultural Affairs database; the buildings are used by Shokin Shoyu Co., Ltd.
Public AccessWorking brewery. No general admission; exterior visible from the public lane. Cellar visits have been accepted by advance arrangement on weekdays.

References

National Cultural Properties Database, Agency for Cultural Affairs — Yamayoshi Shoyu Assakuba oyobi Shikomiba
https://kunishitei.bunka.go.jp/heritage/detail/101/00004667
National Cultural Properties Database, Agency for Cultural Affairs — Yamayoshi Shoyu Moromi-gura
https://kunishitei.bunka.go.jp/heritage/detail/101/00004666
Shokin Shoyu Co., Ltd. — Company profile
https://shokinshoyu.jp/company/
Shodoshima Town — Modern industrial heritage of Hishio-no-Sato
https://www.town.shodoshima.lg.jp/gyousei/kakuka/shogaigakushuka/2/1/3151.html
Shodoshima Town — Sanuki soy sauce brewing techniques, Registered Intangible Folk Cultural Property
https://www.town.shodoshima.lg.jp/gyousei/kakuka/shogaigakushuka/2/5909.html
Morita Co., Ltd. — Marukin Soy Sauce Memorial Museum
https://marukin.moritakk.com/kinenkan/

Last verified: 2026.08.09