GMOs in Cheese?

Larry A. Law

For those of us who love cheese and want to eat what's clean and natural, it isn't just about checking to see if the milk cheese is made from comes from cows that are grass-fed, start to finish. There's a new hidden concern. There's a bioengineered (GMO) element in the process of turning milk into cheese. An outstanding book for those interested in cheese (making it themselves and/or understanding the different kinds) is called The Art of Natural Cheesemaking: Using Traditional, Non-Industrial Methods and Raw Ingredients to Make the World's Best Cheeses. The author mentions in this book something about bioengineering (GMOs) that I had never heard.

There are several steps and ingredients to change milk into cheese. One of the key ingredients is called rennet (pronounced reh-nut). Rennet is the enzyme used to cause the separation of milk proteins into solid curds and whey. It is essential for making different types of cheese such as cheddar, mozzarella, aged cheeses, as well as hard cheese like Parmesan, Gorgonzola, and Gruyere. There are four types of rennet used in cheesemaking.

Four Types of Rennet

1. Animal Rennet

This is also called true rennet and is a mixture of enzymes, including chymosin and pepsin that help coagulate milk into cheese. Originally, rennet came from the stomachs of un-weened ruminants—cows (calfs), sheep (lamb), and goats (kid). As babies, these ruminants have what is called a milk stomach. In essence, the babies make cheese in their stomach so they can get the most out of the milk. As the animal grows and begins to eat more grass, these enzymes occur less as the need for milk reduces. In the US, animal rennet is considered unethical because it comes from milk-fed calves (a by-product of the veal industry). Consequently, it is increasingly expensive and difficult to obtain as the market for veal declines.

2. Vegetable Rennet

These are coagulating agents from plants (nettles, artichokes, and cardoon thistle). They are not as effective as other milk-clotting enzymes. In addition, commercial supplies of these rennets are difficult to find. 

3. Microbial Rennet

Microbial rennet is a coagulating agent produced by fermenting a specific type of mold, yeast, or fungus in a lab setting. Microbial rennet can be non-GMO, but the microorganisms used to produce it may be fed genetically modified organisms (GMOs). The organisms are often fed soy, which is most likely GMO. However, some microbial rennets, like Standing Stone Farms' Non-GMO Microbial Rennet, are produced without animal products and, therefore, are not bioengineered. Unfortunately, they do not make cheese as well as animal rennet. The synthetic enzymes give cheese a rubbery texture and, when aged, an unsettling bitterness. 

​4. FPC Enzyme (Fermentation Produced Chymosin)

FPC is produced with the aid of transgenic bacteria (species of E. coli or Aspergillus niger) that have been given a gene from a cow expressing the production of chymosin; this allows the microorganisms to synthesize the enzyme in bio-reactors without the slaughter of calves. Most American cheesemakers use this type of rennet in cheese production. This rennet is definitely created as a result of bioengineering (GMO). ​

Options

Bioengineered/genetically modified (GM) rennet was not subject to a review when it was granted Generally Regarded As Safe (GRAS) status by the US Food and Drug Administration (FDA). The FDA considers GMO as natural as nature's food and therefore, requires no safety testing. Apparently, this is the strange logic: companies can get a patent since the product is so distincet and unique, yet that product does not require testing because it is sufficiently similar to 'natural food.' It's insane, but that is their regulatory determination (sponsored and paid for by the bioengineering industry!).

​What can consumers do? The author suggests that if you are interested in making your own cheese, you use products from WALCOREN, a company that produces a certified non-GMO rennet. It's much harder when buying store-bought cheese: manufacturers are not required to label the fact that they are using bioengineered bacteria or feeding them GMO feed. Even a USDA Organic label doesn't guarantee non-GMO in this case, because the USDA makes an exception for processing aids used manufacturing the cheese. Hopefully, with this summary of the different types of rennet, you will be able to discern a little more detail about the nature of the cheese you purchase (see picture above with goat milk and vegetable rennet listed on the ingredient lablel).