The largest soy sauce producing facility in the world celebrated five decades in Wisconsin on Friday. Kikkoman, a Japan-based food manufacturer, opened its Walworth soy sauce plant in 1973. Gov. Tony Evers declared June 9 Kikkoman Day to “celebrate our partnership, our shared success and the future of Kikkoman.” Business leaders and politicians from Wisconsin and Japan met in Walworth County to commemorate the milestone.
Kikkoman announced that it would donate over $5 million to public universities in Wisconsin. The donations include $3 million to the University of Wisconsin-Madison’s College of Agriculture & Life Sciences and $2 million to the University of Wisconsin-Milwaukee’s School of Freshwater Sciences.
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UW-Madison plans to use its donation to support its agricultural programs. The Wisconsin Integrated Cropping Systems Trial studies how “different approaches to farming can affect the harvest and greenhouse gas,” said Jennifer Mnookin, the chancellor of UW-Madison. Mnookin also announced that funds from Kikkoman’s donation will be used for the university’s Grassland 2.0 program, which “promote[s] livestock raising in ways that improve soil health and water quality, … reduce flooding and enhance biodiversity.”
Mark Mone, the UWM chancellor, announced that funds will be used to develop Maggi Sue, the “most advanced designed research vessel for the Great Lakes.” Mone remarked that the seacraft is a “drastic” improvement from UWM’s current Korean-War era research boat.

Kikkoman, which traces its history back over 300 years in Japan, wanted to expand its soy sauce production into North America in the early ’70s. Expansion was a significant risk for the company. Moving into the North American market would cost more capital than the company had at the time, and failure could mean the end of Kikkoman. The first two attempts at North American expansion were rejected by the company’s board before they granted approval on the third attempt.
The company’s search started with 200 proposed plant locations. As the search narrowed, Walworth became the top candidate due to Wisconsin’s central location in the country, its close proximity to soybean and wheat-producing regions, and an ample supply of groundwater. Another important factor was Walworth’s “hardworking people,” said Kikkoman’s honorary CEO Yuzaboro Mogi. “So [Kikkoman’s] can expect high productivity [from workers.] … Also, the people around here are very friendly.”
Wisconsin’s plant became the “model for worldwide expansion,” Mogi said. In the fifty years since the plant was built, Kikkoman saw production increase by 30 times. Kikkoman uses four ingredients to create its soy sauce: water, soybeans, wheat and salt. The ingredients are fermented for six months and regularly checked by workers to ensure the sauce is healthy and bubbling. Fermenting soy sauce gives it a fuller taste, rounding out the saltiness with a tangy umami. Non-fermented soy sauces give off a harsher, bitter saltiness.
“I look forward to what we can accomplish over the next 50 years [with Kikkoman],” Mnookin said.