Q: Is “low temperature pasteurized” milk as safe to drink as regular pasteurized milk? Is it more healthful?
A: Low temperature pasteurization, also called vat or batch pasteurization, is one of several acceptable ways to pasteurize milk, a process used to kill harmful pathogens. It’s clearly a safer choice than raw (unpasteurized) milk, which has been the source of numerous outbreaks of foodborne illness over the years.
In regular pasteurization—the standard method used by large dairy operations—milk is heated to high temperature for a short time (161°F for 15 seconds). In vat pasteurization, milk is heated in small batches to a lower temperature for a longer time (145°F for 30 minutes) and then rapidly cooled. Flavor is better preserved, and usually the milk is not homogenized, so that a layer of cream coats the top.
In the early years of pasteurization, vat pasteurization was the norm. It has become somewhat trendy again as more small dairy processors are using it to appeal to shoppers seeking milk that is more “farm-fresh,” including those who might ordinarily go for raw milk but can’t get it due to restrictions on its sale.
Proponents of vat-pasteurized milk tout it as a healthier choice than regular pasteurized milk because the processing is “gentler” and thus preserves more potentially beneficial substances. It’s true that heat can damage some proteins and other substances in milk. But according to Purdue University Cooperative Extension Service, some milk proteins (including whey and casein) and bovine lactoferrin (which has antibacterial properties) are heat-stable and thus not affected by pasteurization. And any nutrient losses from any pasteurization, whether high-heat or low-heat, are negligible.
Buy vat-pasteurized milk if you like the way it tastes and don’t mind paying extra for it. Available at some health food stores and farmers’ markets, the milk is also often local and organic and from pasture-raised cows. Don’t count on it, though, to have added health benefits compared to regular pasteurized milk.