Kitchen
Why Shallow Containers Help Leftovers Cool Faster
A deep pot of hot soup or a large mass of leftovers can stay warm in the center much longer than the same food divided among smaller, shallow containers. More surface area and less depth let heat escape faster after the food goes into the refrigerator.
FDA specifically recommends dividing large amounts of leftovers into shallow containers for quicker cooling. This is one of those simple storage habits that improves safety without requiring any special equipment.