The company’s current corporate information lists 922 employees and ¥71.4 billion in sales for the fiscal year ending December 2025.

Foundation in 1645

Yamasa’s history begins in 1645, during Japan’s Edo period. Founder Gihei Hamaguchi established soy sauce production in Choshi, a coastal city in present-day Chiba Prefecture.

Choshi proved particularly suitable for soy sauce brewing because of its relatively mild climate and humidity, conditions favourable to the microorganisms used in fermentation. Yamasa has continued to identify its brewing tradition with this location for centuries.[1]

The company therefore has a history of more than 380 years, making Yamasa one of the world’s oldest continuously operating food brands.

Recognition during the Edo period

Yamasa’s reputation for quality grew as soy sauce became increasingly important in Japanese cuisine.

The company’s distinctive logo incorporates the Japanese character 「上」 (jō or ue). Yamasa explains that this mark is connected to its receiving the designation “Saijō Shōyu” (最上醤油) in 1864, recognising its soy sauce as being of particularly high quality.[1]

In 1895, Yamasa was also selected as a supplier to the Imperial Household, further strengthening its reputation as a premium soy sauce producer.

Scientific development

Although Yamasa is strongly associated with traditional Japanese food, the company eventually developed substantial scientific and biotechnology capabilities.

In 1899, Yamasa established what it describes as the first Japanese soy sauce laboratory. This was an early example of the company’s attempt to combine traditional brewing knowledge with scientific research.[2]

In 1928, Yamasa reorganised as a corporation.

A major technological development came in 1957, when Yamasa developed a method for producing umami seasonings from RNA-related compounds. This work ultimately became the foundation for businesses involving nucleic-acid-related compounds, pharmaceutical ingredients and other biochemical products.[3]

One of the central elements of Yamasa’s identity is its koji culture.

Soy sauce is produced through fermentation involving microorganisms, particularly Aspergillus oryzae and related koji cultures. Yamasa states that its proprietary “Yamasa-koji” tradition has been maintained and developed over generations.

Rather than treating tradition simply as keeping an old recipe unchanged, Yamasa describes its philosophy as combining inherited knowledge with continuous efforts to improve quality.[4]

This combination of:

• traditional fermentation,
• proprietary koji culture,
• controlled brewing,
• scientific research, and
• modern manufacturing

is a major part of the brand’s identity.

Yamasa’s best-known product is shoyu, the Japanese style of fermented soy sauce.

The company’s U.S. business describes its shoyu as having a characteristic red colour, aroma and umami, designed to enhance rather than overwhelm the underlying flavours of food.[2]

A standard Yamasa shoyu is made from ingredients including:

• water
• soybeans
• wheat
• salt
• alcohol, used to help retain freshness

according to the U.S. product specification.[2]

Soy sauce is not simply a salty liquid. Fermentation produces numerous flavour compounds that contribute to umami, aroma, colour and complexity. This is why high-quality shoyu can be used not only as a dipping sauce but also as a seasoning during cooking.

Although soy sauce remains the company’s signature product, Yamasa has expanded substantially beyond traditional shoyu.

Shoyu and soy sauces

Depending on the market, Yamasa offers products such as:

• Regular Shoyu
• Reduced-Sodium Shoyu
• Tamari
• Organic Tamari
• Specialty Japanese-style soy sauces
• Sushi and sashimi-oriented sauces

Yamasa USA currently describes its product portfolio as including shoyus, broths and soups, marinades and sauces.[2]

Marinades and sauces

Yamasa also produces sauces and marinades designed for applications beyond traditional Japanese cuisine.

These products extend the brand into foods such as meat, seafood, vegetables, burgers and other Western dishes while maintaining a Japanese seasoning foundation.[2]

Ramen products

The company has also entered the ramen category. Yamasa USA lists Shoyu, Miso and Tonkotsu ramen broth concentrates, as well as white miso soup concentrate.[2]

Yamasa has developed an international presence, particularly in the United States.

According to Yamasa USA, the company established its U.S. corporation in 1992, completed its U.S. brewery in 1994, and began brewing soy sauce there. The U.S. brewery is located in Salem, Oregon, in the Willamette Valley.[2]

This is an important part of Yamasa’s international strategy: instead of simply exporting Japanese-made soy sauce, the company established local production while maintaining the brewing techniques associated with its Japanese operations.

Yamasa USA describes this philosophy with the positioning “Japanese Tradition. Crafted in America.” Its website states that artisans in Oregon are trained by Japanese counterparts and that the company’s brewing processes draw on Yamasa’s long-established Japanese methods.[2]

Yamasa became closely associated with the development and popularisation of Japanese cuisine, particularly through its soy sauce.

Its historical development coincided with the growth of major Japanese foods and culinary traditions during the Edo period. Yamasa itself notes the relationship between the spread of soy sauce and the development of foods such as sushi, tempura and kabayaki.[4]

Soy sauce became a fundamental seasoning in Japanese cooking because it could simultaneously contribute:

• saltiness
• umami
• aroma
• colour
• fermented complexity

This versatility helped make soy sauce one of the foundational ingredients of Japanese cuisine.

An interesting aspect of Yamasa is that it is not exclusively a food company.

Its biochemical operations grew from research originally connected with fermentation and nucleic-acid science. Yamasa discovered Nuclease P1, an enzyme capable of selectively breaking down RNA into 5′-nucleotides. In 1957, the company developed technology for efficiently separating these compounds and established industrial production methods for nucleic-acid-based umami ingredients.[3]

The resulting expertise expanded into:

• pharmaceutical active ingredients
• pharmaceutical intermediates
• food additives
• fine chemicals
• cosmetic-related ingredients
• research products
• diagnostic products

Yamasa therefore represents an unusual example of a traditional food manufacturer evolving into a broader biotechnology and life-sciences company.[3]

Yamasa also developed a diagnostics business based on technologies originating from its nucleic-acid and biochemical research.

The company entered the life-sciences field in the 1960s and subsequently developed research reagents and diagnostic products. Its diagnostic history includes work involving cyclic AMP, PTH testing, monoclonal antibodies and other in-vitro diagnostic technologies.[5]

This diversification is significant because the same company that began with soy sauce fermentation in 1645 eventually developed technologies used in pharmaceutical and diagnostic applications.

Yamasa’s principal Japanese production base remains in Choshi, Chiba.

The Choshi facility occupies approximately 70,000 tsubo, roughly equivalent to four Tokyo Domes, and manufactures and ships soy sauce, seasonings, pharmaceutical-related products and other goods.

Yamasa also operates production in the United States through its Salem, Oregon facility, allowing the company to serve the North American market through local manufacturing.[2]

Yamasa’s brand identity is essentially built around a balance between tradition and technology.

Its positioning can be summarised as:

Centuries-old Japanese craftsmanship + modern scientific manufacturing + international accessibility

The company emphasises that its history does not mean simply reproducing the past. Instead, Yamasa presents its tradition as an obligation to continually pursue better quality.[4]

The brand’s visual identity is particularly recognisable through its Yamasa logo and the 「上」 character, which links the modern brand to its historical reputation for high-quality soy sauce.

The U.S. milestones are documented by Yamasa USA, while the Japanese company’s corporate history documents its earlier food and biotechnology development.[2]

Today, Yamasa is best understood as two closely connected identities.

First, it is a historic Japanese food brand whose name is strongly associated with premium soy sauce and Japanese seasonings. Its core brand story rests on centuries of fermentation expertise and its origins in Choshi.

Second, Yamasa is a diversified technology-oriented company involved in nucleic-acid-related chemicals, pharmaceutical ingredients and diagnostic technologies. These businesses grew from scientific capabilities developed alongside its traditional food manufacturing.[3]

That combination makes Yamasa unusual among heritage food brands: it has preserved a 17th-century food tradition while developing into a modern food, biochemical and life-sciences enterprise.

In summary, Yamasa is a Japanese company founded in 1645 in Choshi, best known worldwide for its traditionally brewed shoyu, but whose centuries of fermentation and biochemical research have also led it into seasonings, food ingredients, pharmaceuticals, fine chemicals and diagnostic technologies.[1]

1. Brands 〖ヤマサ醤油株式会社〗
2. About Yamasa USA
3. About us | YAMASA CORPORATION Biochemicals Division
4. 伝統 | ヤマサ醤油株式会社 採用サイト
5. Corporate Information | YAMASA CORPORATION Diagnostics