You may never have heard of a twin screw extruder, but here’s a hint: You can make your own Cheetos with one.
It’s a key piece of equipment in the food industry, and also one of many tools at the University of Minnesota’s Joseph J. Warthenson Food Processing Center on the St. Paul Campus (also known as the pilot plant).
The unique workshop bustles with students, faculty and industry developers working out new ideas. Its skilled staff and specialized equipment facilitate tests of novel products and processes. Its licensed cheese production facility is used by artisanal cheese makers to develop small batches for retail and distribution. And it is the birthplace of several popular U of M-developed cheeses, including Nuworld Cheese, an all-white cheese with the flavor of blue cheese, and Minnesota Blue Cheese.
A self-supporting laboratory
The pilot plant is completely self-supporting, covering its costs through its programs, consultation, and services for the food industry as well as through public sales of its cheese and ice cream.
Tonya Schoenfuss, Ph.D., is faculty advisor to the lab and speaks with pride about its historic and current projects. “The pilot plant was originally built in 1959 for research in dairy product production, and soon became home to food and nutrition as well. We serve three interests: research, teaching and industry outreach.”
University of MinnesotaThere’s a long list of equipment available at the plant. From those with appetizing names like butter churn and cheese vat to less-wholesome-sounding tools like the desludging centrifuge and twin screw extruder. This last, extraordinary machine is more fun than it sounds. You can put dry ingredients in one end, add moist ingredients, mix them, and push them out under pressure – even cooking them along the way if you wish. You can make cereals, pastas, and yes, something Cheeto-ish.
The variety of equipment, explains Schoenfuss, enables food researchers and developers to test out products for mass production, since similar equipment is used in large-scale food manufacturing. Schoenfuss has used the extruder to pioneer new ways to use dried milk in food manufacturing, resulting in a process that is both cost-effective and offers marketing benefits as well.
The university has also conducted joint projects with outside companies. For example, through joint research, it developed Crystalban, an ingredient used by some cheese makers to prevent calcium from crystalizing into crunchy lumps in cheese. An outside firm pays royalties to the university to make and sell the ingredient.
The lab serves large companies like General Mills and Cargill, as well as small shops. Businesses try out new ingredients and make small batches of products for testing. Some companies rent the facility to manufacture products. For example, Northern Lights blue cheese is made onsite at the lab. Others seek consultation and training. Eichtens Cheese Farm, well-known to travelers on U.S. Highway 8, honed its craft at the pilot plant.
Students in the university’s Food Science program learn food processing and food engineering at the lab and go on to serve in quality control, product development, food safety, sales, regulation and related food science disciplines.
Testing the goods
But for the general public, the best way to get to know the work of the pilot plant may be to sample its wares. Products made there are on sale every Wednesday from 3:00 to 5:00 p.m. in the Dairy Salesroom (housed in the Andrew Boss Lab of Meat Science building on the St. Paul campus.) The items for sale almost always include two staples of Minnesota life—cheese and ice cream.
The store is now combining with the Meat Sciences store, with a grand opening on July 3. Customers will be able to purchase a variety of fresh beef, pork, lamb, and sausages along with their cheese and ice cream. “There’s often a line at the store when it opens,” says Schoenfuss. “What gets offered varies from week to week, but we sell quite a bit each Wednesday.
In the end, the pilot plant goes beyond its service to the food industry and development of future food engineers. It’s also a great place to pick up the basics for a fine summer barbecue.