Let Hot Food Cool Completely Before Refrigerating It
It's true that putting a big pot of piping hot soup directly into the fridge isn't ideal (it makes the motor work harder), but the other extreme—letting that minestrone sit out until it's cold and then packing it up for storage—isn't great, either (because microorganisms that could lead to foodborne illness tend to multiply in conditions between 40 degrees and 140 degrees). Lisa Yakas, who works in the consumer products division of NSF International, a nonprofit public health and safety company, suggests transferring the hot soup to smaller containers, which will help it cool more quickly than it would in the pot. They can sit on the counter, uncovered, for two hours. Then, snap on the lids and refrigerate.