A Lesson on Rennet

In the next couple weeks I am hoping to add on a Farmer's Cheese Board on the menu at Flora. It will include local cheeses obtained from neighborhood farmer's markets around Seattle. Excited about the idea, I went in search of fun and different cheeses at the Ballard Farmer's Market. "One thing though..." Nat, the owner of Cafe Flora tells me before I began, "... be sure the cheeses you chose use vegetable rennet, not animal."

For a minute I vaguely remember a day in culinary school when we talked about cheese-making, and animal vs. vegetable rennet. And you would think that having worked in a creamery in Italy for a few months, I would know the difference. But I was notorious for not being fully aware (or awake) during class, and the farmer's I worked with in Italy didn't speak much English, so trying to extract information from them on how they made their cheese was difficult, I was more focused on keeping up with the goats than anything else. So I did some research and found the pros and cons of both.

First off:

Rennet- Is an enzyme used in cheese-making, that is added to milk to separate the solid curds (what becomes cheese) from the liquid whey. The two most common kinds are animal and vegetable.

Animal Rennet
This type of rennet is extracted from the stomach of a young calf, lamb or goat. The active enzyme is  this rennet is called chymosin, and is more promeninet in younger calves (they are still weaning off their mother and need it to digest milk). The stomachs of the calves are soaked in salt water, and sometimes whey, filtered, and the remaining rennet is used in cheese making.

Pros- Great for aged cheeses, some say provides a cleaner flavor (some vegetable rennets can leave a bitter aftertaste).
Cons- Not vegetarian friendly, limited supply.

Vegetable Rennet
Rennet derived from plant, fungi, molds or microbial sources that produce the same enzyme as animals. Thistle is a common plant that you can extract rennet from.

Pros- Vegetarian friendly, easily found, kosher friendly.
Cons- Not as effective as animal with whey/curd separation, especially for aged cheeses. The difference though is considered minimal. Sometimes leaves an aftertaste.

So next time you buy cheese at your local farmer's market, ask what kind of rennet they use, and see if you can taste the difference!

Baaaa! Cheese is awesome!