"Your Parmesan cheese products do not contain any Parmesan cheese" is not a letter you want to get from the Food and Drug Administration if you're a company that manufactures Parmesan cheese products. But that's exactly what a 2013 letter from the FDA to Pennsylvania's Castle Cheese Inc. stated, per BuzzFeed—and an investigation by Bloomberg shows that's just the edge of the cheese wheel. After the FDA discovered that Castle was cramming its Parmesan cheese with lower-quality substitutes (e.g., Swiss, mozzarella, white cheddar) and cellulose (a filler made out of wood pulp that's legal in small amounts), then distributing it to grocery chains nationwide, Bloomberg decided to pick up some store-bought grated cheese and have it tested by an independent lab. And the results showed many supermarkets' Parmesan cheese suffered from the same issue.
Although a food technologist for the Wisconsin Center for Dairy Research says cellulose is permitted as a cheese filler as long as it doesn't exceed 4% of the final product, a Walmart grated Parm came in at 7.8% cellulose, while a Jewel-Osco version registered at 8.8%. And a Whole Foods brand whose label didn't indicate any cellulose tested at 0.3%. Bloomberg also obtained the FDA's Castle report through an FOIA request and found "no parmesan cheese was used to manufacture" either a Target Market Pantry brand or two versions sold by Associated Wholesale Grocers—which appeared confusing to Target, as a rep told Bloomberg that Castle has never been one of its vendors (they're looking into it). But why are the cheesemakers doing this? Money, it appears. "The bad guys win and the rule-followers lose," the executive VP of Cheese Merchants of America says, adding that competitors with subpar products often underbid him by up to 30%. (The FDA went after cheesemakers for their wooden aging racks a couple of years back.)