Japan Firm Aims to Grab Future with New Sushi Vinegar Flavors; Company’s Sushi Rice Flavor Unchanged for Over 60 Years

By Hiroki Kitano / Yomiuri Shimbun Staff Writer

15:12 JST, April 27, 2025

Tamanoi Vinegar Co. has been producing Sushinoko, a powdered sushi vinegar product that allows customers to easily make sushi rice, for more than 60 years.

The flavor has remained unchanged since it debuted, but last month, the company started selling Aka Sushinoko, a flavoring for onigiri rice balls, in an effort to attract younger customers.

The company has a rich history.

Back in the 1950s, many people made sushi rice at home. However, vinegar would be delivered in large jars, which was expensive and required a lot of effort.

The company saw that making vinegar into a powdered product would allow it to be delivered to more people.

Driven by the concept, the company did extensive research and became the first firm in the world to make powdered vinegar.

However, when exposed to moisture, the powder would clump together. After a lot of trial and error, researchers found that adding sugar to the mixture would reduce its absorbency.

In 1963, the company put the product on the market as flavored sushi vinegar .

It was not popular among older homemakers, who were confident about their cooking, so the company set its sights on younger people. Tamanoi Vinegar began handing out product samples at kindergartens and ran TV commercials. As a result of these efforts, sales gradually rose.

Ideas garner young fans

The ratio of vinegar, sugar and salt remains the same today, and the packaging has not changed either.

While retaining fans by maintaining its taste and packaging, the company also faced the challenge of trying to attract younger customers, many of whom were unaware of the product.

In February 2023, Rihoko Kawai, 28, who was in charge of product planning, was trying to figure out how to make the product more popular among young people. Then, an idea came to her when she saw a post on social media.

The post said, “Potato chips taste better after adding Sushinoko into the [bag] and shaking it.”

Kawai then asked the supermarkets that sold Sushinoko nationwide to place the product next to potato chips. She also asked the stores to display ads on the sales floor to promote the product. The product’s weekly sales almost quadrupled compared to the previous week.

The idea of selling a limited-time product, with the packaging design changed for the first time, was also due to a social media post.

Kawai noticed how the similarity of the words “Sushinoko” and “Oshinoko,” a popular anime, had started trending on social media.

In June 2024, the company and the anime collaborated to make limited-time packaging featuring a few of the characters from the show, creating a lot of buzz.

Crafting new product

At around the same time, the idea of creating new flavors to “keep up with the times” was raised.

Takaya Harino, 41, who became the company’s president in April 2024, participated in the discussions, and the focus became about developing a product for onigiri rice balls.

Onigiri has becomes more popular, even overseas, and onigiri made with sushi rice has reportedly been a hit.

Risa Kanayama, 26, in charge of product research, and two others formed a project team and started developing a new product.

What flavor should the company try to make? Kanayama and other members of the team prepared various dashi broths and conducted taste tests using five cups of rice every day.

In the process, they also added different flavors such as garlic and salted cod roe with red pepper. But none of them tasted quite right.

They then went back to the drawing board and focused more on the taste of the broth. They combined soup made from dried bonito flakes and one made from dried horse mackerel flakes, adding vinegar and sake lees for aroma and richness.

The rice turned reddish when the mixture was added, so the company named it Aka (red) Sushinoko and put it on sale on March 1.

“The hardest part was creating the right balance between the traditional sour flavor of Sushinoko and the new product,” Kanayama said.

Kawai added, “We want to increase the number of customers by developing various ideas.”

While honoring the taste the company has maintained for so long, Tamanoi Vinegar aims to come up with new ideas in the future.