For most foods evolution has graced us with the ability to see, smell or taste any issues well before they actually become a problem. There are some things you have to look out for like botulism or salmonella, but for simple foods like bread and milk there isn't much point in taking precautions
But then I am in UK where milk is easily obtained in 2 pint or less packages and is all long term - over a week. It is harder to gat 4 int or gallon containers which I think are more common in the US.
Except sometimes the 1/2 gallons will be randomly on sale where you can get like 3 of them for the price of a gallon. Milk economics makes no sense to me. But yeah, it's usually cheaper to buy more than you need and just throw it out if you don't use it, as is the American way.
