Hey I have a query about milk. Why does organic milk take so much longer to expire than the other kind? At my supermarket, the organic milk usually expires in a month and the regular milk in a week.
You’d think non-organic milk would have more preservatives or something, eh? Does milk expire faster than it did, say thirty years ago?
Mooooo.
ANSWER PERSON RESPONDS: This indicates that the milk has been “ultra-pasteurized” to extend shelf life. This involves a very high temperature (280° F), but for a very short time (2 seconds), compared to old-fashioned pasteurization (161.5° F for 15 sec.).
AP can only guess why this might be used more with organic milk, but there are surely a number of economic and publicity reasons. If organic milk doesn’t sell as fast as industrially produced milk, maybe the producers and retailers feel this is nessesary. They perhaps want to maintain a repuation of a product that doesn’t go bad quickly. One suggestion is that the lack of anti-biotics in the milk requires it to be ultra-pasteurized, but I don’t know the scientific validity of this. It could be that due to fewer packaging centers, it’s shipped from farther away and needs longer shelf life. Probably just a rumor.
There is supposedly a “UHT” designation on the front gable top on Horizon brand milk if it’s ultra-pasteurized. Some is, some isn’t.
I’d think that with the adoption of ultra-pasteurization, expiration is longer than it used to be.
There are more details at this webpage: http://www.nbc4.com/answerstoaskliz2005/4494693/detail.html or the Wikipedia article on pasteurization at: http://en.wikipedia.org/wiki/Pasteurization or this university web site on UHT pasteurization: http://www.foodsci.uoguelph.ca/dairyedu/uht.html