Some cheeses are, indeed, made without rennet, which curdles milk protein. A few varieties are made with no curdling agent at all, and others use plant-based forms of the enzyme found in rennet. There is also a rennet that is made from genetically modified fungi. Vegetarians who are interested in finding a "true" vegetarian cheese should consider the options listed below.
Cheese Without Rennet
Rice University identifies the following brands of cheese as being rennet-free. These are young cheeses that aren't aged for a long time and cheeses that are served fresh, soon after production.
In Nutrition Therapy and Pathophysiology, (page 293) Marcia Nelms, Kathryn Sucher, and Sara Long note cottage cheese is traditionally made without the addition of rennet and are instead coagulated with an acidic ingredient such as vinegar. All brands of cottage cheese, including Kraft and Horizon Organic, are safe choices for those looking for rennet-free cheese.
Kraft Philadelphia cream cheese is a rennet-free cheese. It's a good option for everything from bagels to recipes.
Stella provolone has an intense flavor. This makes it a great addition to casseroles or warm sandwiches.
Organic Valley ricotta cheese offers a slightly sweet flavor than some alternatives. It is rich, light, and made without rennet.
Cheese Made with Non-Animal Rennet
According to a list orginally compiled and published by Joyous Living, the following brands of cheese are made with vegetarian forms of rennet. Most cheese in the United States is made with one of the four types of vegetable rennet.
- Microbial rennet. This enzyme is produced from fungi or mold. It is much cheaper than calves' rennet, but it can have a bitter flavor. Cheese makers are more likely to use this product in young cheese, since the aging process strengthens flavors in the cheese.
- Fermentation-produced chymosin (FPC). This compound is used in more than 90% of all cheeses made in the United States, according to the Dairy Research Institute. It doesn't affect the flavor of the cheese as much as microbial rennet does. This type of rennet can be made by inserting the DNA that produces the rennet enzyme into fungi. In other words, this product is almost always genetically modified.
- Vegetable rennet. Some plants contain compounds that will curdle milk just like rennet does. The plant most commonly used for this compound is the thistle. But this rennet should only be used for cheese made from sheep or goat's milk, since it will make cow's milk cheese bitter.
Labels won't always tell the whole story about the food, since the terms used are not always clear. The FDA states that "enzymes of animal, plant, or microbial origin may be declared as "enzymes" on a cheese label, with no delineation between animal forms and vegetable forms. Look for the term "vegetarian" or "vegan" on the label to narrow down your choices.
If you want to avoid GM or GMO foods, look for the "Non-GMO product" label on the cheeses you buy. A cheese label that states the product is "100% Organic" or "USDA Organic" is helpful too, but that doesn't always mean the type of rennet used isn't GMO. The best way to determine if a cheese contains rennet, whether animal or plant-based or GMO, is to call the company and ask.
Also be aware that companies often change the ingredients they use when they make a product, so a cheese made with vegetarian-friendly rennet one week may be made with animal rennet the next. Some cheeses are also made with animal products, such as Vitamin A Palmitate, which is sometimes made with fish liver oil.
Stay True to Vegetarian Principles
To ensure you are truly following a vegetarian diet, look for cheeses that have been made without the addition of animal rennet. Read labels carefully and check before you buy!