Many cheeses in the US are vegetarian, as they use a microbial rennet source. Still, there are places that use animal-derived rennet sources. Products made with animal-derived rennet sources are not vegetarian. Rennet that comes from an animal is from the stomach lining of a slaughtered cow, sheep, or goat. Some places also use rennet derived from slaughtered pigs. So to answer the question that many people have:
Is Kraft Parmesan grated cheese vegetarian? Do they use animal or microbial sources of rennet?
To get the answer to this question I contacted the company directly. Here's what they wrote back:
"Here is the information you requested about the enzymes we use in KRAFT Parmesan Grated Cheese.
The process of converting milk into cheese is dependent on coagulating milk through the use of enzymes. We only use enzymes purchased from reputable suppliers for processing our various lines of cheese.
KRAFT NATURAL SWISS & KRAFT GRATED PARMESAN - Kraft Natural Swiss and Kraft Grated Parmesan utilize microbial rennet which is NOT made with enzymes extracted from animal tissue - grated parmesan may contain lipase (from animal source). Please check ingredient line on the product packaging. Below are the cheese enzymes.
RENNET / CHYMOSIN / RENNIN:
RENNET is a complex (or grouping) of enzymes produced in any mammalian stomach to digest the mother's milk, and is often used in the production of cheese. Rennet contains many enzymes that coagulate milk, causing it to separate into solids (curds) and liquid (whey). RENNET is animal-sourced.
The active enzyme in RENNET is called chymosin or rennin.
CHYMOSIN (rennin) may be obtained from RENNET, an animal source, but it may also be obtained from several other microbial or vegetable sources.
There are also other important enzymes in RENNET, such as pepsin and lipase.
Is an animal sourced enzyme which develops the flavor of mild to older flavored cheeses. If the word "lipase" appears in the ingredient line of a Kraft product then it will be of animal origin.
Is an enzyme produced by a pure culture of microorganisms (such as molds and yeast) There are many sources of enzymes, ranging from plants, fungi, and microbial sources, that can substitute for animal rennet and are suitable for consumption by vegetarians."
So there you have it! You need to read the ingredient list. If it HAS lipase in it then it is not vegetarian, as lipase is taken from the stomach of slaughtered calves and lambs. If the product does not have lipase listed as an ingredient then it is vegetarian, because they report that they use microbial rennet in their Kraft grated parmesan cheese.
You can find some great vegan parmesan alternatives today, so you don't even have to worry about whether or not it's vegetarian and you can avoid any animal ingredients. Today you can easily find products like Go Veggie parmesan and NOOCH IT! in mainstream grocery stores and online. And they taste good! It's also important to note here that Asiago cheese is another one that is usually not vegetarian and for the same reasons that many parmesan cheeses are not vegetarian.
Learn more about if all parmesan cheese is vegetarian here.
Update January 2020: I checked once again with Kraft to see if anything had changed. They sent me the same response as they previously had 1.5 years prior when I contacted them and did the original post. If the Kraft parmesan has lipase listed as an ingredient then it is not vegetarian. If their parmesan does not have lipase listed as an ingredient then it is vegetarian.