In the same keep-it-cold vein, minimize the time the milk is out of the
fridge. Set a house rule to never set the milk down on the counter. I
vaguely remember hearing some statistic that every 10 minutes (or maybe
it was every hour) that the milk is out of the fridge reduces the
length it will keep by one day. So, don't set the milk on the table
while you're eating your cereal - pour it on and then put the container
back in the fridge. I've had pretty good success with this strategy -
milk usually lasts at least a week to two weeks after the sell-by date.


Hope that helps,
Melissa