Variety of cheeses on serving platter

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reducing agent

Commercial source: vegetable, mineral, or synthetic.
Examples: bioflavinoids, sulfur dioxide.
Definition: A substance used to maintain the taste and color of foods which contain minerals.
Typically Vegan

refined beet sugar

Commercial source: vegetable.
Used in: processed foods, baked goods.
Definition: A source of regined sugar.


Commercial source: animal (calf-derived). There are alternatives which are derived from plants, bacteria, or molds.
Used in: cheese, junket (a custard containing this enzyme).
Definition: Enzyme used for the coagulation of milk in the cheese making process. Historically, often was a mixture containing an enzyme (rennin) derived principally from the stomachs of young calves and used to make cheese.
May Be Non-Vegetarian

Production information: According to information from the Wisconsin Center for Dairy Research, approximately 95 percent of cheese in the U.S. now is made with non-animal rennet. The enzyme in Kraft® Singles is not from an animal source. The enzymes in the cheese powder in their Macaroni and Cheese are from an animal source (calves and sheep).   See further info underneath the R’s guide. Also see lipase.


Commercial source: fungal, bacterial, animal (calf-derived).
Used in: rennet.
Definition: An enzyme derived principally from the stomachs of young calves and used to make rennet and cheese. See rennet.
May Be Non-Vegetarian


Commercial source: vegetable or synthetic.
Example: petroleum hydrocarbon resin.
Used in: chewing gum base.
Definition: A class of substances which is commonly used as a protective, wax-like coating for fruits and vegetables, and as a chewing gum base.


Also known as: vitamin B-2, lacto-flavin, riboflavin-5-phosphate.
Commercial source: Typically bacterial or fungal.
Exists in: organ meats, fish, milk, eggs, dry yeast, leafy green vegetables.
Used in: dry baby and breakfast cereals, peanut butter, enriched foods (e.g., macaroni, flour, breads and rolls).
Definition: A B vitamin which may be used as a food coloring or as a nutrient fortifier of foods.
Typically Vegan

Production information: Schiff Products Inc., a manufacturer of riboflavin, reports that it may be produced through a yeast fermentation or through a synthetic route. Rhone-Poulenc Inc., another manufacturer, reports that dextrose is their fermentation medium in the production of riboflavin.

rice syrup

Commercial source: vegetable.
Used in: baked goods, cereal.
Definition: A sweetener derived from brown rice.

Production information: California Natural Products, a major manufacturer of rice syrup, reports that no bone filter or gelatin is used in their rice syrup processing.


Also known as: colophony.
Commercial source: vegetable.
Used in: chewing gum.
Definition: A tree substance which is used to soften chewing gum.

royal jelly

Commercial source: animal (insect).
Used in: nutrient supplements.
Definition: A substance produced by the glands of bees and used as a source of B vitamins, minerals, and amino acids.


Also known as: sodium benzosulfimide.
Commercial source: synthetic.
Used in: diet foods and beverages, processed foods, toothpaste, mouthwash.
Definition: An artificial sweetener which yields less than two calories per gram.



Rennet is defined as the inner lining of the fourth stomach of calves and other young ruminants or as an extract made from the stomach lining of a ruminant, used in cheesemaking to curdle milk. Rennet also broadly refers to any enzyme used for the coagulation of milk in the cheesemaking process. The active component in rennet is known as rennin, the actual enzyme that causes milk to coagulate. This enzyme must be added to break down the proteins that keep milk in its liquid form. Dean Sommer, a Cheese and Food Technologist at the Wisconsin Center for Dairy Research (WCDR), estimates that 5-10 percent of the rennet is retained in the cheese curds, while the rest stays in the liquid whey.

Organic Valley, a major producer of organic cheeses stated, Historically, rennet was extracted from calf stomachs by killing the calves, cutting the stomach into strips, scraping the lining to remove surface fat, stretching it onto racks where moisture is removed, grinding it, and then finally mixing it with a salt solution until the rennin is extracted. The rennin (also known as chymosin) was needed to coagulate milk during the cheesemaking process, allowing the liquid whey to be removed from the curds that are later pressed into cheese. Some small cheese operations wishing to maintain tradition, especially those in Europe but even in the United States, still produce cheese in this manner.

According to the WCDR, some people, namely traditional cheesemakers and some artisan and specialty cheesemakers, continue to believe that calf rennet produces the best-flavored aged cheeses, especially aged cheddar, Parmesan, and others. In fact, veal calf rennet was once considered the Cadillac of rennets and secured the highest price among all milk coagulants.

Rennet is used only for making certain types of cheese. Other dairy products, such as ice cream, sour cream, and yogurt, are not made with rennet.

Types of Rennet

According to the WCDR, there are four types of rennet: calf rennet, microbial rennet, fermentation-produced chymosin, and vegetable coagulants.

Calf Rennet

Calf rennet has traditionally been the enzyme of choice in cheesemaking. However, between supply problems and animal rights, religious, and food safety issues, calf rennet is now used to make less than 5 percent of all cheese produced today, according to the WCDR.

Microbial Rennet

Microbial rennets are those produced by fungi, such as Rhizomucor miehei. Typically, these rennets are less expensive than calf rennet, but they lack the same protein breakdown specificity that calf rennet has. This results in smaller cheese yields and, as a side effect, a somewhat bitter taste to the final cheese product. Microbial rennets also have other chemical and physical properties, such as increased heat resistance and residual amylase (an enzyme responsible for starch breakdown) activity, that can lead to functional problems in some foods to which whey had been added. However, microbial rennet manufacturers report that most of these issues have been resolved.

Fermentation-Produced Chymosin

Fermentation-produced chymosin (FPC) is by far the most common form of a milk-coagulating enzyme used today, according to the WCDR. Potter said that approximately 70 percent of all cheese is produced with FPC, while approximately 25 percent is made with microbial coagulants and the remaining 5 percent is made from calf rennet.

Of all the types of rennet, FPC most closely performs like calf rennet in cheesemaking because of similarities in chemical action and structure. It is not, strictly speaking, like the microbial rennets described above, although it also is produced by a fermentation process. Unlike microbial rennet, FPC is produced by genetically-modified microorganisms. The microbes are removed from the final product after extraction, purification, and standardization of the chymosin; therefore, the chymosin is not generally considered a GMO product.

FPC costs more than microbial rennet but less than calf rennet. Many in the cheese industry feel it produces a cheese of equal quality to that produced by calf rennet. Because it is a fermentation product, the raw materials for its production are readily available, resulting in a stable supply at a consistent price for the cheese industry.

Vegetable Coagulants

In parts of Europe, vegetable coagulants are used to make cheese. These are produced by plants such as cynara, a type of thistle.

Does USDA Certified Organic Cheese Contain Animal Rennet?

Recently discovered that USDA certified organic sugar has never passed through a bone char filter and, therefore, is always vegan. I wondered if one could make an analogous claim about USDA certified organic cheeses with respect to animal rennet, i.e., that animal rennet is never used in organic cheeses. The short answer is ‘no.’

Most organic cheesemakers with whom we spoke market their cheeses simply as USDA Certified Organic without specifying whether that cheese is, according to the USDA’s classification scheme, 100 percent, 95 percent, or at least 70 percent organic or if it’s Made with Organic Ingredients. In practically every case, it appears from our survey of many organic cheese companies that today’s USDA Certified Organic cheese is almost never 100 percent organic. Readers may note that, to use the phrase USDA Certified Organic, at least 95 percent of a product’s ingredients must be organic.

It is the presence of a very small quantity of non-organic rennet (and, in some cases, non-organic processing aids and/or preservatives) that leave the cheesemakers unable to claim that their cheeses are 100 percent USDA Certified Organic. This is true whether the rennet is animal or microbially derived. In most cases, organic cheesemakers today use microbially derived rennet produced through a fermentation process (i.e., the ‘microbial rennet’ described above). According to the National Organic Program (NOP), this fungal-derived rennet is not a genetically-engineered organism (GMO). The complete prohibition of GMOs in any product labeled USDA Certified Organic is a basic tenet of the NOP.

Many cheesemakers label this enzyme as ‘vegetable rennet.’ According to the WCDR, calling fungal-derived rennet ‘vegetable rennet’ is a misnomer, but it is still very commonly labeled this way. According to Joan Shaffer of the NOP’s media office, the microbially-derived rennet is not something that can be ‘organic’ since it is not an agricultural product; therefore, no cheese made with microbially-derived rennet can ever be 100 percent organic. However, the microbially derived rennet can be in an organic product that is 95 percent or 70 percent organic because it is on the National List of Allowed and Prohibited Substances as an allowed substance that can be used to make or can serve as ingredients in USDA Certified Organic products. (Analogous, USDA Certified Organic sugar on the market today is also 95% Organic and not 100% Organic because of the use of a non-organic processing aid that is allowable under NOP rules.)


Concerned readers should also be aware that some organic cheeses, like some non-organic cheeses, may contain other animal-derived enzymes. The most common one is lipase, responsible for breaking up fat molecules. Potter said that lipases are structurally very complex compared to rennets. Fermentation-derived lipases on the market (today) do not function as well as animal lipases, he commented. This is because animal lipases are a complex blend of lipases. The arrangement and ratios needed for optimum functionality has not been replicated. The result in cheese is too much of one flavor compound developed and an imbalance of flavor during the cheese ripening process. Thus, most lipases used in cheese today are derived from animals.

Organic Valley, for example, uses microbial rennet and animal-derived lipase in its Romano cheese and Blue Cheese Crumbles. The animal source is not listed on the label. Horizon, a major producer of organic cheese, told us by telephone that they use ‘microbial’ rennet in all of their cheeses. They did not make any further comment, saying that it was proprietary information. Kraft Foods, the major non-organic cheese manufacturer, stated that their Parmesan and Romano Cheese Blend is made with ‘microbial rennet,’ but animal-derived lipase is also used to impart the distinctive flavor to Romano cheese. Again, the animal source is not listed on the label.

What Major Companies Say about Animal-Derived Enzymes

According to the enzyme companies, it appears that very little calf rennet (less than 5 percent) is used anymore. On the other hand, some major cheesemakers have said that calf rennet is still used in several of their cheese varieties. Kraft, by one of the largest cheese companies, said that, when the word ‘enzymes’ by itself appears on a label, consumers should understand that both animal-derived and microbial-derived enzymes may have been used. They emphasized that the box in the store is the best place to find out ingredient information for a specific Kraft product; however, the box often just says ‘enzymes,’ leaving the consumers in doubt. Kraft stated that when microbial rennet is used, it will be labeled as ‘microbial rennet.’

However, on the Kraft website, there is a FAQ sheet that explicitly states that Kraft Macaroni & Cheese does contain enzymes derived from animals (calves and sheep), found in the animals’ stomach and intestines. The writer was informed by telephone that this applies to all varieties of Kraft Macaroni & Cheese. A Kraft representative also said that Kraft Natural Swiss and Kraft Grated Parmesan utilize microbial rennet that is NOT made with enzymes extracted from animal tissue. (This is interesting because many other people in the cheese industry stated that Parmesan cheese is one variety that is often made with calf rennet.) As mentioned previously, the Kraft Grated Parmesan Cheese may contain lipase (from an animal source).

In addition,  Sargento, another major cheese manufacturer, was asked about the enzymes used in their cheeses. They estimated that 11 percent of their cheese brands possibly contain animal rennet. (They did not specify how this percentage was related to their total sales volume.)