Do I have to let food cool down before I put it in Tupperware or do I just put it in Tupperware and cover it while it's still hot? My girlfriend says I have to let it cool down first, then put it in Tupperware. If I cover it while it is still hot the heat will spoil the food. I don't understand why. I also asked my friend and he told me his wife tells him the same thing. I have always thought since it is hot it should be covered. I do get it makes moisture, but does that spoil the food.
I searched online but all I find is "hot food in refrigerator" could not find answer.
This is not a question about how long do I have to let food sit before I refrigerate it, but if I should cover hot foods right away or not.