I’m sure this has been asked before, though I couldn’t find anything. If so, I apologize.
I’ve often heard that microwaves cook from the inside out. It seems to be the case with some things, but not others. For instance, I put a pint of ice cream in the microwave and it melts in the center while the outside is still cold and hard. However, I put a bowl of leftover spaghetti in the microwave, and the center is still cold while the outside edges get hot.
I’m just wondering what causes this disparity. It seems to vary from food to food, though perhaps the container has something to do with it as well. But i’m not talking about any container that has those heating strips meant to get hot in the microwave to cook food faster (often found in tv dinners).