ONE WILD WORLD — NEWSLETTER

Issue #015  |  Food Lies  |  April 2026

In 2012, an FDA inspector walked into a Pennsylvania cheese factory and made a discovery that sparked a federal fraud case, a wave of class-action lawsuits against Kraft and Walmart, and a quiet realisation for millions of American shoppers: the “100% grated Parmesan” they’d been shaking onto their spaghetti for decades wasn’t even entirely cheese.

BY THE NUMBERS

In November 2012, the US Food and Drug Administration received a tip from a former plant manager at a small cheese factory in Slippery Rock, Pennsylvania. The factory was called Castle Cheese Inc. It supplied grated Parmesan and Romano to some of the biggest grocery chains in America — including Target, Associated Wholesale Grocers, and hundreds of regional supermarkets.

The tip alleged something that sounded absurd. Castle Cheese, the caller said, was selling bags labelled “100% Parmesan” that contained no actual Parmesan at all.

The FDA sent inspectors. They raided the facility in January 2013. What they found was almost exactly what the whistleblower had described.

According to the FDA’s report, the products Castle Cheese was distributing under store-brand names like Market Pantry, Always Save, and Best Choice — all labelled as “100% grated Parmesan” — were in fact a mixture of Swiss, mozzarella, white cheddar, and an anti-clumping additive called cellulose. The cellulose was derived, in significant part, from wood pulp.

There was no Parmesan in the Parmesan.

The investigation eventually established that Castle Cheese had been doing this for the better part of three decades. The company’s own co-CEO, George Myrter, admitted to FDA inspectors during the raid that he already knew the cheeses were made with fillers.

His daughter, Michelle Myrter, was the company president. In February 2016, she pleaded guilty in federal court in the Western District of Pennsylvania to aiding and abetting the introduction of adulterated and misbranded food products into interstate commerce. Two other companies controlled by the family — Universal Cheese & Drying, Inc. and International Packing, LLC — also pleaded guilty, to conspiracy and money laundering.

Each company had to forfeit $500,000 to the United States government. Michelle Myrter herself was sentenced in October 2016 to three years’ probation, a $5,000 fine, and 200 hours of community service at a food bank. She could have faced up to a year in prison.

Castle Cheese Inc. — which had been supplying thousands of retail stores across 30 states — went into bankruptcy proceedings.

The Castle Cheese case broke publicly in February 2016, when Bloomberg News ran a detailed investigation of the FDA’s findings. But Bloomberg didn’t stop there. They went to their local supermarket, bought bags of grated Parmesan from major brands, and sent them off to an independent lab in Wisconsin to test how much cellulose they actually contained.

The results got everyone’s attention.

Class-action lawsuits followed almost immediately. Kraft Heinz, Walmart, and the retailer carrying Essential Everyday were all sued across multiple federal courts for violating state consumer-fraud laws. Kraft’s defence was, essentially, that cellulose was FDA-approved, and that its levels were technically within acceptable limits — though that defence got harder to sustain once the independent test numbers came in.

This is the part where the story usually loses nuance, so let’s be careful.

Cellulose is a plant fibre — the same structural material that makes up the walls of every plant cell on Earth. It’s in celery, in lettuce, in wheat, in apples. When it’s added to food, it’s commonly derived from wood pulp, because wood pulp is cheap and widely available. But it can equally be extracted from cotton, corn cobs, or other plant sources.

At low concentrations — up to about 4% — the FDA classifies it as Generally Recognised As Safe. It’s used throughout the food industry as an anti-clumping agent, a fibre supplement, and a texture modifier. Ice cream manufacturers add it to create a creamier mouthfeel. Bread manufacturers add it to bulk out their loaves. It’s not secretly poisoning you.

The problem is not that cellulose exists in food. The problem is that a cheap wood-derived filler was being used to dilute a premium product — and the product was still being marketed and sold as “100% Parmesan.” That’s fraud. And in Castle Cheese’s case, it was criminal fraud.

The cheapest, fastest test for whether a hard Italian cheese is the real thing is the rind. Authentic Parmigiano-Reggiano — the protected Italian designation that the US “Parmesan” is loosely based on — has the words “Parmigiano-Reggiano” stamped in dotted letters directly into the wheel’s rind, all the way around. If you’re buying a wedge and that stamp isn’t there, it isn’t Parmigiano-Reggiano. It might be decent cheese. But it isn’t that.

Grated cheese is harder. You can’t see a rind. What you can do is read the ingredients list. If cellulose, potassium sorbate, or an “anti-caking agent” is listed, the product contains filler. The only question is how much.

A block of real Parmigiano-Reggiano, grated fresh, contains one ingredient: milk (with salt and rennet used in the making). That’s it. Anything on the shelf with a longer ingredient list than that is a processed product pretending to be cheese.

A tip from a former plant manager. An FDA raid on a small Pennsylvania factory. A family dynasty that had been selling “100% Parmesan” for thirty years without any Parmesan in it. A criminal conviction. And the quiet, awkward discovery that the green shaker-bottle in almost every American kitchen is up to 8% wood.

The cheese industry calls it “filler.” The FDA calls it “cellulose.” Everyone else calls it what it is.

SOURCES

Bloomberg News — “The Parmesan You Sprinkle on Your Penne Could Be Wood” (16 February 2016)

US Attorney’s Office, Western District of Pennsylvania — Castle Cheese plea agreement and sentencing (February 2016, October 2016)

US Food and Drug Administration — Castle Cheese Inc. warning letter and inspection report (2012–2013)

Time Magazine — “FDA Finds Wood Pulp in Major Parmesan Cheese Brands” (February 2016)

Snopes — “Wood in Cheese?” fact-check on cellulose claims (February 2016)

Food Safety News — “Pulp fiction and fact: Wood, cellulose and Parmesan cheese” (March 2016)

The Counter — “There is wood pulp in your 100 percent grated cheese” coverage of 7th Circuit class-action reopening (2021)

Consorzio del Formaggio Parmigiano-Reggiano — Protected Designation of Origin (PDO) standards