Some spots in my refrigerator are colder than others, and sometimes I accidentally put milk in a spot that is cold enough to freeze it.
Now I have a gallon or half-gallon of frozen milk, and want to unfreeze it. I can move it to a warmer part of the refrigerator and wait for it to heat up, but this is inefficient--it can take days to become drinkable again.
I can't just leave the milk out at room temperature or microwave it, because that would ruin the milk.
How can I unfreeze/thaw my milk so that it is drinkable again, without having to wait forever in the process?