Is nothing sacred? No, really: The U.S. Food and Drug Administration is reporting that your so-called parmesan cheese, especially the grated kind, may in fact be up to 40% non-cheese product. In this case, the filler being used by Castle Cheese Inc. (but found to be a much wider-spread industry practice) is wood pulp, or cellulose.

Though the additive, which is used to prevent clumping, is safe up to 2%, it was found that cheeses from several brands claiming to produce 100% pure parmesan had amounts totaling anywhere from 3.8% to 8.8%. Wal-Mart Stores Inc.’s Great Value 100% Grated Parmesan Cheese registered 7.8%, and others, like Target's Market Pantry 100% Grated Parmesan Cheese, included no parmesan at all, instead featuring a cheaper mixture of Swiss, mozzarella, white cheddar, and cellulose. The reason for such false labelings is, simply, the bottom line: Mixing high-grade, high-quality pecorino with other ingredients with longer shelf lives saves lots of money.

According to Bloomberg Business, the FDA has mostly focused on health hazards in the past. These findings point to a trend of increased liability for manufacturers mislabeling their products and misleading consumers.

Our takeaway? Rather than buying pre-grated parmesan, which is where the high levels of filler were found, go for a block and grate it yourself.