Originally Posted by TRRed
I'm fortunate enough to live near a dairy store, who's milk is very recently "harvested" and bottled in glass. Their code dates are accurate to slightly conservative (i.e. I don't remember any of their milk turning before the code date). Milk I bought on 8/17 has a code date of 9/2, so that's about 16 days, which would seem a reasonable estimate for shelf life of milk, if kept properly refrigerated. If I look for milk in a regular grocery store, it is a challenge to find a carton with a code date of more than a week, which may suggest how much shipping time is involved.
On a tangent, I've had much better luck with milk bottled in glass, rather in plastic. I get my milk from Ronnybrook Farms, and my experience has been that when I buy it from them at the farmers' market in glass, it'll last a few days past the date, but when I buy their milk in plastic from Fresh Direct (a NYC internet grocery) it'll go nasty basically on the date. Then again, that may say more about Fresh Direct than it says about glass vs. plastic.
I also work on the smell test, and the "creates chunks when you pour it into coffee" test. And the "itty bitty sip" test when I don't trust my nose.
There's one brand of organic milk in the store (Amish something, I think) that always has a really long date on it--I wonder if they've done some sort of extra processing?