Pasteurization key to expiration dates
Q: How come the expiration dates on soy milk and organic milk are two weeks longer than the dates for regular milk?
A: The reason soy and organic milk lasts longer, before it is open, is the pasteurization process. Regular milk goes through a pasteurization process that heats it up to 161 degrees for 15 seconds. Soy and organic milk go through ultra pasteurization. This heats the milk up to 280 degrees for 2 seconds. Ultra pasteurization keeps the milk fresher longer. Both of these processes kill bacteria.
After any of the milk is open (soy, organic milk or regular milk) it is only good for 7-10 days.
Sue Kosharek of Rochester is a registered dietitian in private practice. Questions should be sent to the Life section, Post-Bulletin, 18 First Ave. S.E., Rochester, MN 55904 or you also may e-mail questions to email@example.com.