Maybe in its last life Wisconsin was a province in Asia. Our unassuming Midwestern state, which is famously known for its cheese and beer, is a major producer of Asian staples like ginseng and soy sauce. Wisconsin’s relationship with Kikkoman Foods, the world’s largest producer of naturally brewed soy sauce, began only 35 years ago, when the Kikkoman Corp. became the first Japanese firm to establish a production plant in the United States. Walworth, Wis., a small agricultural community just north of the Illinois border, was chosen as the site for the new facility because of its central location not only within the soybean and wheat-growing region, but also within the United States.Kikkoman was also attracted to Wisconsin’s clean air and fresh groundwater, as both are integral to the fermentation process.

According to Kikkoman Foods, their soy sauce has its origins in the 17th century, when the Mogi and Takanashi families began soy sauce production along the Edo River in Noda, a small city in the Japanese prefecture of Chiba. If Mickey Mouse, McDonald’s and Microsoft have taught us anything, it’s the power of a logo. In Japanese folklore, the tortoise lives for 10,000 years and thus stands as a symbol of longevity. The Mogi family chose “kikko,” or tortoise shell, and “man,” meaning 10,000, as the trademarkfirst for their top soy sauce, and later for the name of their company. As the company states, “The hexagonal logo found on Kikkoman products represents a tortoise shell with the Chinese character for 10,000 inscribed inside.”

Dan Miller, vice president of Kikkoman Foods, explains that the Walworth plant is the highest-producing soy sauce plant in the world, producing approximately 29 million gallons of product last year, or roughly 30% of Kikkoman’s soy sauce. “This is the only plant we have here in North America that makes retail products of Kikkoman soy sauce,” Miller says. “Every bottle in the United States and North America came off our production lines.”

The Walworth plant makes 39 different Kikkoman products, all of which, with one exception, are some variation of soy sauce or have soy sauce as an ingredient.

Much like wine or beer, soy sauces vary in fragrance, taste and consistency depending on the region where they are produced. Some are chemically manufactured, while others, like Kikkoman, are naturally brewed. Natural brewing occurs over the course of three distinct stages: koji-making, brine fermentation and refining.

Kikkoman begins the natural brewing process by blending soybeans and wheat together. A proprietary microorganism called aspergillus is introduced and the mixture is allowed to mature for three days. The resulting culture, koji, is transferred to fermentation tanks where it is mixed with saltwater to produce a mash called moromi. This blend is allowed to ferment for several months, during which time the soybeans and wheat become a semi-liquid “mature” mash. According to Miller, it is during the fermentation process that various flavor notes of the sauce some subtle, some distinctdevelop. Next the raw soy sauce is separated from the solids by pressing it through filtration cloth. The resulting liquid is then refined, pasteurized and packaged as finished soy sauce.

“Minimizing our environmental impact is very important to us as a company,” Miller says. “Every waste stream that is produced from our process is recycled in some way.” The solid material that remains after filtration is sold as animal feed and the remaining soy oil is used for biodiesel and machine lubrication.

At the plant’s 30-year anniversary, Kikkoman announced a $100 million phased expansion that would add 40% to the Wisconsin facility’s capacity. Miller concludes that they are finished with roughly 60%-70% of that expansion. For its 35th anniversary, Kikkoman Foods announced the establishment of a research and development lab at the University Research Park in Madison. According to Miller, the new facility will utilize UW-Madison’s research in food science to explore what he calls the three Fsthe flavor, fortification and functionality of food. In addition, the Kikkoman Foundation is granting $100,000 in scholarships to students studying at UW- Madison’s Nelson Institute for Environmental Studies.