Next time you sprinkle some grated parmesan on your spaghetti, you may be getting more than you bargained for — in the form of wood pulp. Yes, that’s right. Wood pulp.

The U.S. Food & Drug Administration recently confirmed that Pennsylvania-based Castle Cheese, Inc., was adding wood pulp as a filler to its “100 percent real” Parmesan cheese over the course of many years in an effort to save money. In some cases, the amount of wood pulp was rather significant, prompting outrage and concern over intentional or negligence food mislabeling.

Wood pulp, also called cellulose, is the main ingredient in paper.

The growing problem of adding fillers to Parmesan products is not limited to Castle Cheese, however. In tests conducted by Bloomberg News on “100 percent” grated Parmesan cheese, products from Jewel-Osco, Wal-Mart, and Kraft Heinz Food Company all showed that cellulose was added as a filler.

Based on these findings, the FDA recently warned that Parmesan cheese fraud has become a serious problem for American consumers. In fact, several companies accused of adding fillers to their cheese products are now facing legal action.

For several years, Castle Cheese has been battling charges that it misbranded its products. The company is also in the middle of a rare criminal case, although it has discontinued its cheese products and previously filed for bankruptcy in 2014.

Kraft has also been hit with a proposed class action lawsuit in a California federal court. If certified, the suit would include all nationwide buyers of the company’s grated Parmesan cheese. The plaintiffs are seeking a declaratory judgment, compensatory and punitive damages, and injunctive relief under California’s Consumers Legal Remedies Act.

So what does this mean for Parmesan cheese lovers? Two things: buy non-grated cheese and read the labels. However, keep in mind that cheese industry experts say stricter labeling laws are needed because about 40 percent of what is being sold to consumers isn’t even a cheese product.

The FDA’s investigation into Castle Cheese and the proposed class-action suit against Kraft are alarming evidence that consumers are being misled about food products and other consumer goods. The attorneys at Sommers Schwartz continue to monitor this and other instances of alleged consumer fraud, and will continue to provide updates.