I picked up a liter of vat pasteurized milk at a specialty market the other day. It was expensive (about $3.50 plus the $1.50 bottle credit which I can get back if I return the bottle) but I was curious enough to splurge. I had never heard of vat pasteurized milk before but the milk was also local, sustainable, organic, non-homogenized, and came from Jersey cows so there was a lot to be curious about. What is vat pasteurization and would this milk taste noticeably different than my everyday organic from Trader Joe's?

Even beyond whole or 2%, there are many choices when we go to buy our milk these days. Let's start with the simplest: homogenized or non-homogenized. Homogenized milk simply means that the milk has been processed so that the fat globules are evenly distributed throughout the milk. When milk is non-homogenized, the fat separates and forms a layer of cream on the top. You can either scoop off this delicious stuff and use it as a special treat in your coffee or drizzled on your morning berries, or you can shake the bottle and temporarily distribute the cream into the milk. Some people claim that non-homogenized milk is better for you as the processing that is used in homogenized milk isn't heart healthy.

The purpose of pasteurization is to kill harmful bacteria that may be present in milk. UHP (or Ultra-Pasturized) means that the milk has ben heated to a very high temperature (280ºF for 2 seconds) making a very shelf-stable product as the milk can keep under refrigeration for several weeks. But usually we are purchasing what is just known and labeled as pasteurized milk, also called as HTST or High Temperature Short Time Pasteurization, in which milk is heated at 161ºF for 15 seconds. This kind of milk can last 2 to 3 weeks in your refrigerator.

With vat pasteurization, milk is held at 145ºF for 30 minutes and then quickly cooled. This retains a high percentage of the milk's natural enzymes and beneficial bacteria which adds to the flavor and heath benefits of the milk. It lasts about as long in your refrigerator as HTST milk. Many people are turning to vat pasteurized milk as an alternative to raw (or unpasteurized) milk which can be difficult to get in some areas. It tends to cost a little more than conventionally pasteurized milk because the process is lengthier and therefore more expensive.

But how does vat pasteurized milk taste? While I like milk, I don't generally drink it as a beverage anymore so I poured myself a small glass and took a sip. The texture was richer and creamier than my usual (2%, organic, homogenized, HTST pasteurized) milk. The taste was milk-like, only amplified with a fuller and richer flavor. It didn't taste quite as sweet and had a slightly grassy finish. It was really delicious stuff, both on its own and in my morning tea!

The cost would prohibit me from buying this milk on a regular basis. Still, I wouldn't hesitate for special occasions or an occasional splurge. I would love to cook with this milk, for instance, using recipes that would highlight its flavor, such as a panna cotta. Or a fresh, homemade cheese would be delicious.

I'm curious how the lower pasteurization temperature and lack of homogenization would affect recipes. Has anyone had any experience with this?

It should be said that the milk I tried was from St. Benoit, a Sonoma County based dairy that makes great yogurt and some of the best yogurt cheese I've ever tasted. They use Jersey cows which are known to produce richer, creamier milk. A quick Google search reveals that many smaller, family-owned dairies across the US are using the vat pasteurizing process and that the milk is less expensive (as with most things!) than it is here.

Related: Food Science: What's the Deal with Ultra-Pastuerization?

(Images: Dana Velden)