Freezer burn is a condition that occurs when frozen food is exposed to air inside the freezer. It causes the food's surface to become dehydrated, resulting in changes in texture, flavor, and appearance. Freezer burn doesn't make the food unsafe to eat, but it can affect its quality and taste.
The process of freezer burn happens due to sublimation, which is the direct conversion of water from a solid (ice) to a gas (water vapor) without passing through the liquid phase (water). When frozen food is exposed to air, the frozen water molecules on the food's surface can undergo sublimation, turning into water vapor and escaping into the air. As a result, the food becomes dry and develops white or grayish patches on its surface.
Freezer burn is more likely to occur if the food is improperly stored or if it remains in the freezer for an extended period. To prevent freezer burn, it's essential to store food properly in airtight containers or freezer bags, removing as much air as possible before sealing. Labeling and dating frozen items can also help ensure they are consumed within a reasonable time frame.
While freezer burn affects the quality of the food, it doesn't make the food unsafe to eat. However, it's best to trim off freezer-burned areas before cooking or consuming the food, as those portions might have an unpleasant taste and texture. Proper storage techniques and rotation of frozen items can help minimize the occurrence of freezer burn and maintain the quality of frozen foods for a more extended period.