Mostly out of curiosity:
I hear a lot of the time that you should never add freshly pumped milk to a cold container of milk already in the fridge.
I understand that putting freshly pumped milk into a cold container of milk warms up the cold milk, but why is this so awful that it's a complete no-no? You've got people like Jack Newman saying that milk can stay at room temperature for hours without going bad. So warming up cold milk should clearly cut down on the number of hours it's good in the fridge, but make it completely bad? Is there something else that happens? Otherwise, I'm having a hard time buying this one.