So if raw milk cheese tastes so much better, why oh why would cheesemakers choose to pasteurize? What are the advantages, and are all forms of pasteurization created equal?
First things first: Pasteurization is a heat treatment that kills the naturally occurring bacteria found in unpasteurized (that is, raw) milk. But remember, not all bacteria is bad bacteria. In fact, most of it isn't! But when you kill bacteria, you also kill flavor-producing enzymes, which is why so many people love cheese made with raw milk. In the States, the FDA regulates that raw milk cheese must be aged for a minimum of 60 days, the thought being that any potentially harmful pathogens in raw milk can't live beyond that amount of time.
So you'll never find young cheeses-- meaning the soft, fresher, so-delicious styles that are gooey and generally higher in moisture-- unless they're made with pasteurized milk, much to the chagrin of many. And nevermind that there are more cases of food-borne illnesses linked to pasteurized milk cheese than to raw milk cheese, even in countries that don't regulate the age of their raw milk cheeses!
So why do cheesemakers pasteurize, if so many people are such supporters of raw milk? Other than wanting to making younger than 60 days old, here are a few key reasons why some cheesemakers favor using pasteurized milk:
- To make great raw milk cheese, you have to start with great raw product. If you're working with lots of milk with questionable origin, your best bet is to pasteurize.
- If you're making cheese on a cooperative level, that is, if you're getting your milk from a number of different farms, it's often best to pasteurize, especially if the raw milk is traveling a far distance. The mixing of different milks and the transferring of milk from one vat to another increases the probability of contamination.
- Pasteurization is ideal for cheesemakers who want a consistent product that will be the same every single time. Pasteurizing eliminates variation in cheeses dues to seasons or animals' diet. Pasteurizing is a way to make every batch of milk begin at the same starting point, without bacterial variables.
- It's easier to automate the cheesemaking process if you're using pasteurized milk. Fewer checkpoints have to be in place because the milk will react the same way every time, while raw milk can sometimes react differently in different circumstances. That's why many cheesemaking facilities that make cheese on a larger scale will use pasteurized milk.
Not all pasteurization is created equal! Thermalization is a gentler form of pasteurization, when the milk is slowly heated to 145 degrees for thirty minutes, which retains some of the original character of the raw milk. Flash pasteurization, on the other hand, heats milk to 200 degrees for just a few brisk and very non-gentle seconds. It's used mainly for highly industrial cheeses that rely on speed and efficiency over flavor. More and more frequently, cheese shops are starting to delineate the cheeses that are thermalized. Look out for these as a sign of potentially great cheese, made by someone who cares about flavor and who is willing to take the time to pasteurize more gently.
Remember: GREAT — no, EXCELLENT — cheese can be made from pasteurized milk!
Nora Singley is an avid lover of cheese, and for some time she was a Cheesemonger and the Director of Education at Murray's Cheese Shop in New York City, where she continues to teach cheese classes for the public. She is currently an assistant chef on The Martha Stewart Show.