Going Inside the Plant at Nasonville Dairy
Wisconsin-based dairy continues its legacy of sustainable plant operations.

Photos by Barbara Harfmann.
Manufacturing 42 varieties of premium cheese in the heart of America’s Dairyland not only takes a ton of high-quality raw milk — 1.8 million pounds a day, or 534 million pounds annually, to be exact, in the case of Marshfield, Wis.-based Nasonville Dairy. Sanitary plant operations built on careful temperature management, the correct bacterial cultures and rennet along with skill and the patience to develop complex flavors and textures also is needed, explains the dairy’s CEO and Master Cheesemaker Ken Heiman.
Nasonville’s comprehensive cheese portfolio includes the first-place-awarded World Championship Monterey Jack, which took the top prize in 2024; eight SKUs of “hot, hotter and hotter yet” bold cheeses like Jalapeno Pepper and Scorpion Cheddar; 10 flavors of cheese curds such as Everything Bagel and Garlic & Dill, a top-selling flavor; and its often-awarded Feta varieties in spreads, crumbles, in-brine and chunk.
Founded in 1885 as a small co-op before returning to private ownership back to a co-op and switching back to private ownership again in 1985 — a rare occurrence in the dairy industry — Nasonville Dairy not only operates the oldest cheese plant in Wood County, Wis., but is family-owned and -operated by the three Heiman brothers, the aforementioned Ken, Kelvin, manager of Transportation and Distribution, and Kim, manager of Plant Operations.
Spouses along with sons, daughter-in-laws, nieces and nephews and even some grandchildren have contributed to the success of the third- going on fourth-generation, medium-sized cheese processor.
Manager of Plant Operations Kim Heiman tells Dairy Foods that what makes Nasonville plant operations unique is that crux of the company’s main 65,000-square-foot headquarters and plant at 10898 Hwy. 10 West is split between two plants under one roof: the 25,000-square-foot Feta plant and the Cheddar plant, which at 45,000 square feet, runs 40-pound cheddar blocks along with Colby’s, Monterey Jack’s, Asiago’s and Fontina’s with several flavored cheese varieties.
“There’s always more room for automation because I can remember a time when we would handle 300 blocks of cheese in a day using the 40-pound Wilson hoops, and we'd handle 300 of them, so the equivalent of 2,700 to 3,000 of those blocks a day being maneuvered by hand, but if I had employees doing that today, I’d have nobody,” the Master Cheesemaker notes ”Now, it’s a different story with 50 percent of our plants being 65 percent automated.”
Kim Heiman tells Dairy Foods that “the Cheddar side runs about 1.2 million pounds of milk a day, while we take in between 550,000 to 600,000 pounds of milk daily for our Feta plant. What’s really neat is that Nasonville makes about 15% of all the feta produced in the United States. So, obviously that’s a pretty great line and portfolio for us.”
Ken Heiman explains that when making its award-winning Nasonville Feta, the fat goes down while the moisture goes up.

“In feta, I’m going to take it down to 19 to 21 percent fat while taking the moisture up to 51 to 53 percent,” he explains. “This increases the yield and gives one a harder, healthier cheese. Feta also is good for the gut with probiotic yeasts that may lower the pH in your stomach.”
When asked to name the equipment most crucial to dairy operations, Ken Heiman doesn’t hesitate. “Pasteurization is crucial,” he says. “Without that, your plant is automatically down, done. Once the milk is pasteurized and has been tested for safety using bacterial tests, somatic cell counts, and antibiotic testing, it can move to any one of three wings within the plant.
“Pasterization doesn't care what fat content you want to run. It doesn't care what you want to do for moisture on a cheese. It doesn't care,” he stresses. “All it's doing is taking care of your bacteria, making sure that your milk is free and clear [of contaminants] and safe to continue down the production line.”
All the way with whey
Distribution-wise, the dairy’s cheese and whey, the watery part of milk that separates from the curds when milk is curdled and strained, is distributed across the United States, with about 1% being exported internationally to China, Canada, South Korea, Saudi Arabia and Chile. China, Ken Heiman says, receives the bulk of the exports and even with the new administration and talks about tariffs, Nasonville has had to deal with tariffs before.
Fresh milk from 190 Central Wisconsin dairy farms is the heartbeat of Nasonville Dairy’s diverse cheese portfolio, Kim Heiman attests. While Cheddar cheese comprises 60% of the dairy’s product portfolio, other varieties include Colby, Monterey Jack, Farmer’s, Pizza, Feta, Gouda, Fontina and Parmesan along with many flavored cheeses like Blue Marble Jack, Garlic & Herb, and Horseradish.
Yet, only 15% of the dairy’s total cheese production goes out under the familiar Nasonville label; the rest is contract packed and may end up as a food ingredient on a pizza, in a bread, in different entrees or even packaged under different brands, Ken Heiman explains.
Within cheese operations, manufacturers work hard to ensure nothing is wasted. The reason it takes 10 pounds of milk to make one pound of cheese is because 90% of the milk is whey, so the dairy’s whey plant operation is extremely busy. At the endpoint of the joint process, cheese whey is turned into three main salable products: cream, protein and whey lactose.


“A separator is used to separate the cream out first, which we sell to our neighbor, Grassland Dairy in Greenwood, Wis., just 45 minutes away, is the largest family-owned butter plant in the United States. It’s been making premium butter for five generations, Kim Heiman states.
“Once the cream is out, we run the whey through an ultrafiltration system which uses a series of membranes and pressure to separate out the whey protein isolates that are used in cookies, candy bars, baby foods, sports nutrition, muscle building and tissue rebuilding protein drinks,” he continues.
With the help of seamless automation, the lactose is sifted out and run through a reverse osmosis (RO) system which uses membrane filtration and even higher pressure to encapsulate the lactose crystal which is then dried down as a sugar substitute. The process takes just a few minutes.
Saving money through sustainability
“What's left at the end of this process is called cow water or condensate of whey,” Kim Heiman explains. “We utilize that for pre-rinsed water and for our makeup water for our wash units because it's a soft water. We can use less detergent, less chemicals to clean and sanitize. There’s a lot of sanitizing at a cheese plant. We clean equipment, the vats, 13 times in a 12-hour shift. And we operate two, 12-hour shifts, Monday thru Friday, and try to work half-day on Saturday.


“And because this still could have some organic properties, we can't use it as a potable water. But because it’s 110 degrees Fahrenheit, we don’t have to use as many British thermal units (BTUs) to heat the water up, providing additional cost savings.”
Wastewater and how it is disposed of is crucial to dairy plant operations.
“Our Wastewater Treatment facility will run about 250,000 to 300,000 gallons per day that is treated and released back into the stream,” Kim Heiman explains. “We’re required by the Department of Natural Resources and registered by them to make sure all of our water meets very good aquatic life standards so we don't have to worry about fish kills or anything like that.”
The simple things in life
In addition to the Cheddar and Feta plants at its headquarters, the dairy operates a small Marshfield, Wis.-based Milk Bottling plant which supplies milk in recyclable 8-ounce pouches in skim white, 1% white, and 1% chocolate varieties to 21 schools within a 60-mile radius; and Nasonville North, a 15,000-square-foot plant in Curtis, Wis., that runs 25,000 pounds of milk a day in small-sized vats to produce artisan specialty cheese and flavored cheese such as Buffalo Wing, Pepperoni Jack, Horseradish or Feta along with 10 varieties of squeaky fresh cheese curds.
The majority of the products the North plant manufactures is sold at the family-owned Weber’s Farm Store at 9706 County Road H in Marshfield, Wis. Milk products include 2% Reduced Fat Milk, Skim, and 2% Reduced Fat Chocolate Milk. The newest product is the brand’s A2 Protein Milk.
Both the 500-cow Weber’s Farm and Weber’s Farm Store were purchased in 1995 by Ken and Kelvin Heiman. While the brothers continue to influence Weber’s operations, “we’ve really passed the torch to my sons, Ryan and Josh, and to Kal’s son, Andy, who are for all practical purchases ‘in charge,’” says Ken Heiman, laughing. “Andy and Josh primarily focus on herd and crop management, while Ryan helps with managing and production.
“What’s really cool is that all of the milk sold at Weber’s comes solely from our Holstein cows —honestly, you can’t get any fresher, better tasting milk anywhere,” he stresses. “And that’s why Weber’s is such a vibrant part of the community. There’s a playground, we sell soft-serve ice milk in many sizes and flavors and we invite families to ‘enjoy the simple things in life,’ one of our mottos. Families come to shop, relax and play in a fun atmosphere.”
Throughout every step of plant production, Nasonville Dairy’s 235 employees work hard to give their contract manufacturers, foodservice and retail customers the superior taste, creaminess and consistency they deserve.
While the dairy plant is landlocked and in a hilly locale, Ken Heiman says there’s a bit more room for growth.
“We're thinking about a new intake and a new cold milk separator to standardize our milk going into the vats. That's something we’re looking into this year,” Ken Heiman concludes. “Actually, we'll get some of the county road next to us which will allow us to grow. We’ve done really well, knock on wood, and will continue to push the boundaries to grow and expand.”
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