I've seen cartons of "ultra-pasteurized" milk at the grocery store. What is it?
Ultra-pasteurization is a more intense process than regular pasteurization and allows milk to have a longer shelf-life. If you don't mind the higher cost and if your milk tends to spoil before you can finish it, it might be an option for you to consider. (Although, nutritionists might say that if you just started drinking more milk, you wouldn't have to worry about the milk spoiling, now would you?)
Here are the basics: "Pasteurization" means that milk is packaged under sanitary conditions after being heated to a minimum of 161 degrees F for at least 15 seconds, or 145 degrees F for at least 30 minutes. Either heating option kills most bacteria; the type that survive aren't considered harmful but can spoil milk after a period of time. If pasteurized milk is kept properly refrigerated, it can last anywhere from 12 to 21 days after processing; you can generally count on milk to remain fresh from two to five days after the sell-by date on the carton. The colder the storage conditions, the longer milk will last.
"Ultra-pasteurization" means that milk is heated to a minimum of 280 degrees F for at least two seconds. Although the heating period is much shorter than what's used for regular pasteurization, the high heat used in the process is much more lethal to bacteria. Packaging conditions for ultra-pasteurized milk are also more stringent -- practically sterile. In fact, ultra-pasteurized milk would be considered a sterile product if it was canned or otherwise hermetically sealed. All of this means that, when properly refrigerated, ultra-pasteurized milk can last from 30 to 90 days after processing and before the container is opened. After opening, the milk could become contaminated with spoilage bacteria, but you can generally count on it to remain fresh for at least seven to 10 days after the container is opened.
Some people say they think ultra-pasteurized milk has a different flavor, more "cooked" than regular milk, but others don't notice a difference. No matter which kind of milk you choose, be sure your consumption of milk and dairy products meets the Dietary Guidelines for Americans recommendations -- three cups each day for anyone 9 years of age or older. If you can't see yourself drinking that much milk, high-calcium dairy products (yogurt, cheese, ice cream or pudding, for example) count, too. The guidelines encourage fat-free or low-fat choices within the dairy group, not only to reduce calories but also to reduce intake of saturated fats and cholesterol, both of which increase the risk of heart disease. For more information on milk and dairy product recommendations, see http://www.mypyramid.gov/pyramid/milk.html.
Chow Line is a service of Ohio State University Extension and the Ohio Agricultural Research and Development Center. Send questions to Chow Line, c/o Martha Filipic, 2021 Coffey Road, Columbus, OH, 43210-1044, or firstname.lastname@example.org.
Editor: This column was reviewed by Julie Shertzer, registered dietitian and program specialist for Ohio State University Extension in the Department of Human Nutrition, in the College of Education and Human Ecology.