One of the ways I've found to help rehabilitate my ways and perhaps compensate in some way is through my milk purchases. At first glance, organic milk is expensive. To look at a carton of milk and think of paying over $3 for that milk makes one wince. However, first, there truly is a difference in taste. Organic milk is very cold and fresh tasting. That, alone though, does not validate the purchase. What does is the fact that the expiration date on organic milk gives you another good two weeks than you would otherwise get out of your milk purchase. I have been a repeat offender in the area of wasting milk as well...for years. As soon as I started buying it while in the dorm, I realized there would not be too many times that I would even polish off a half gallon within its fresh period. But, to downgrade meant possibly not having enough. And who wants to get stuck with a dry bowl of cereal in the sleepy mornings?
I have learned since this discovery that ultrapasteurization (heating the milk to a higher temp) is what extends the expiration. There is speculation, however, that you should still ditch the milk a week after opening.