Why is the shelf life of organic milk so much longer than non-organic?

June 7, 2005 9:47 AM

Can anyone tell me why the expiration date of organic milk is so much longer than conventional milk..like > 1 month? Any farmers out there? Scientists? Cows? Thank you.
posted by ParisParamus to Science & Nature (14 answers total)

Probably because it's got to be ultrapasteurized due to the organic milk cows' not being fed the antibiotics that non-organic milk cows are. The temperature used for ultra vs. regular pasteurizing is about 2X as high.
posted by shoos at 10:04 AM on June 7, 2005

Let's see: googling "organic milk expiration date", this creamy link floated to the top. To quote:

Ultra High Temperature pasteurization involves superheating and cooling milk at extreme speeds, and extends the product's shelf life from 17 to 45 days. So Emily, you probably have Ultra High Temperature processed milk.

Follow the link for the 'rest of the story' (at bottom of page). ;-P
posted by mischief at 10:24 AM on June 7, 2005

Response by poster: No. No. No. This is not UHT milk; milk in the Tetra Brick; this is normal milk in a normal carton.
posted by ParisParamus at 10:39 AM on June 7, 2005

Response by poster: Shoos, that sounds more plausible.
posted by ParisParamus at 10:40 AM on June 7, 2005

The milk I normally buy has about a 7 day expiry - anything longer must have been processed in some way (there is a trend to put UHT milk in refrigerated cabinets to increase sales)
posted by Lanark at 10:46 AM on June 7, 2005

Uh, how do you know your milk is not ultra high temperature pastuerized? Being in a "normal" carton doesn't mean it isn't.

I have read that the reason organic milk must be ultrapasteurized is because it is frequently shipped from much further away than non-organic milk and must have a longer shelf life.

On preview, I don't understand why what shoos is saying is any more plausible than what mischief is saying.
posted by grouse at 10:46 AM on June 7, 2005

To clarify, I mean that by the time that some organic milk gets to its point of sale, it would already be about to expire if it were pasteurized traditionally.
posted by grouse at 10:51 AM on June 7, 2005

Best answer: Horizon's organic milk is sold in "ordinary" cartons in the refrigerated section of supermarkets, but it is UHT processed and has a 50-day shelf life, ParisParamus. I know that's the brand I can get both in New Hampshire and in New Jersey; is it the one you're using, too?
posted by bcwinters at 10:52 AM on June 7, 2005

Response by poster: Thanks, bcwinters; that must be it. It doesn't taste bad, so good for les fermiers et les vaches biologiques!
posted by ParisParamus at 11:36 AM on June 7, 2005

OTOH I have seen organic milk cartons that have a very short shelf life--like you have to drink them in a few days.
posted by kenko at 11:46 AM on June 7, 2005

another possibility is that the carton seal inside was skived ... (folded over on itself) ... which would give it an extra shelf life of 2 to 3 weeks ... this is because on a regular carton seal the edge of the small panel inside is bare paper and allows eventual contamination from outside ... but if it's folded over on itself, then only the poly coating on the paperboard touches the milk and it will last longer ...

i'm not sure if tetra pack uses this technology, though ... i work for a competitor ...
posted by pyramid termite at 8:14 PM on June 7, 2005

UHT Milk. It's what's for breakfast...next month.
posted by Goofyy at 8:49 PM on June 7, 2005

I've seen some allegations that Horizon [which is sort of a behemoth in the organic milk industry] doesn't quite deserve the label organic. I wouldn't necessarily take them as an example of what more small organic companies do. The milk I get most frequently seems to claim a pretty normal 7-10 day shelf life, although I remember thinking in the store the other day that most of the organic milk seemed to have a long shelf life compared to the major brand around here [Hood.] Perhaps since it's often relatively local [most organic milk here in MA seems to be from neighboring New England states, a short drive away], it is, contrary to what grouse said, actually shipped faster?
posted by ubersturm at 10:14 PM on June 7, 2005

ubersturm: How much longer are we talking about?
posted by grouse at 1:17 AM on June 8, 2005