Ann: Market Update, page-9

About organic milk: If you buy organic milk, you’ve probably noticed that its shelf life (unopened) is much longer than for conventional milk. That’s because the organic milk is ultra-pasteurized, which means it was heated to a much higher temperature than ordinary milk. The Popular Science website says that the extra heating is expensive, and that’s why organic milk costs more. Also, the website says, it can give the milk “a cooked or scorched flavor” (something your Shelf Life Advice guru has never noticed). Remember, once that carton is opened, bacteria go to work on it as they would any other type of milk, so its shelf life is the same as an opened carton of conventional milk.Source(s):Karin E. Allen, Ph.D., Utah State University, Dept. of Nutrition, Dietetics, and Food Sciences