I went to another of those cheese pairing events done by Fromage to Yours a couple of weeks ago. Jackie and Paul Bonacquisti of Bonacquisti Wines paired Colorado cheeses (with one gorgonzola exception) with Colorado wines (specifically, Bonacquisti wines. In the course of the descriptions, Jackie mentioned that there were 6 major cheesemakers in Colorado, but she neglected to specify them. Next time I visited with Jackie, I asked her for the names of the companies and she listed Haystack, Rocking W, and Sunny Breeze as companies she currently carries. She is hoping to carry cheeses from Jumpin' Good Goat. She does not carry cheeses from MouCo, James Ranch and Windsor because she carries only vegetarian cheese. This led me to ask about vegetarian cheese. I mean, I understand that cheese is not in the equation for vegans, but I am basically ovo-lacto (I eat eggs and milk products), so why not all cheese. The answer has to do with rennet and that is quite the tale!
Jackie did not go into great detail, saying only that some cheesemakers use animal rennet, but the cheeses she carries are made with microbial enzymes. When I used those definitions in a general conversation, wouldn't you know that someone wanted to know where animal rennets came from. So here's the longer story:
Animal rennet relates to a natural complex of enzymes in mammalian stomachs to digest mother's milk. Traditionally, stomachs of young calves are dried, cleaned, diced and soaked in saltwater or whey with vinegar or wine. This is then strained and used to coagulate milk in cheesemaking. There are some modern alternatives with freeze-drying and such. As you might guess, there are too few stomachs for modern cheesemaking requirements. In fact, cheesemakers were already seeking alternatives in Homer's time when an extract of fig was used. There are other vegetable rennets, microbial enzymes (mostly from molds and with a bit of bitter taste) and genetically engineered enzymes, all of which are considered vegetarian acceptable and most of which are qualify for Kosher cheese. Cottage cheese, cream cheese, paneer and farmer's cheese are examples of cheese that use acid (generally citric acid) to coagulate the milk.
So now you know more than you ever thought to know about coagulating milk for cheese!