A condition that happens to biological material that is improperly frozen, or frozen too many times. It is a combination of two factors:
  1. The expansion and crystallization of water molecules wreaks havoc on the cell walls and other protein structures of the object, so that when it is thawed, the affected areas become mushy and disgusting.
  2. If your object is not properly wrapped when it goes in the freezer, the sublimation of ice from the object can dry out the surface and alter its structure.
If your food gets freezer burned, you can probably save most of it by just cutting off the affected areas, or removing the layer of 'burnt' food. Or just grit your teeth and eat it. It's not going to kill you.

The rule of thumb on keeping your food from getting freezer burnt is simple:

  • Always wrap whatever you're freezing in something airtight, to keep the water balance.
  • Never freeze something more than once. This is why it is important to know if any sort of meat is fresh or previously frozen before you buy it.