What is “freezer burn?”

    The outcome of frozen food losing its moisture as a result of poor wrapping.

Have you ever wondered what happened to a steak in the freezer that looks discolored and parched? It is covered in frost and there are dry spots on the meat tissue. It looked fine when you froze it a few months ago. What caused this transformation?

When food is frozen as a method of preservation thousands and thousands of water molecules within the steak form ice crystals. These water molecules prefer the most hospitable environment- the coldest place in your freezer. The molecules migrate from the steak to the coldest place they can find, which is often the side of your freezer. The loss of these water molecules causes the steak to become dehydrated. The end result is freezer burn.

So why did this happen?

• Most likely, your food was not tightly wrapped enabling water molecules to escape and seek a better location.
  
  
• Also, freezer burn is likely to occur for items stored in the freezer too long. There is a limit to how long items should be stored in the freezer. Sooner or later the water molecules will find their way out of the frozen food to a colder place in your freezer. (See Refrigerator & Freezer Storage Chart listed in Web resources)
  
  
• The temperature of your freezer may have been above 0 degrees F. Freezer burn will set in from fluctuating temperatures above 0 degrees F.

When water molecules escape from your frozen food, it is also possible for oxygen molecules to seep in. The oxygen molecules can dull the color and modify the flavor of your frozen product.

Food that has freezer burn is safe to eat, but you may find the texture and taste not to your liking. Listed below are Web sites that provide freezing tips so that your frozen food will be in first-rate condition to serve to your friends and family.

Related Web Sites

Everyday Mystery: Who Invented Frozen Food? - This Web page provides information on the invention of frozen food and related resources. Food Marketing Institute: Food Storage Information - This Web site has tips for food storage in a pantry, refrigerator and freezer. National Center for Home Food Preservation: How Do I … freeze - Included on this Web site is general freezing information such as foods that do not freeze, containers for freezing, and tips for thawing and serving. Refrigerator & Freezer Storage Chart - Information of food storage in a refrigerator and freezer inventor of the Week: Clarence Birdseye United States Agriculture Department Food Safety and Inspection Services - A fact sheet on safe food handling when freezing food products.

Further Reading

Frozen food technology. Edited by C.P. Mallett. London, Blackie Academic & Professional, 1993. 339 p. Milius, Susan. Preventing freezer burn. Rodale's Organic Gardening, v. 33, July 1986: 72-75. Quality in frozen food. Edited by Marilyn C. Erickson and Yen-Con Hung. New York, Chapman and Hall, c1997. 484 p. Wolke, Robert L. Burn, baby, freeze! In What Einstein told his cook. New York, W. W. Norton and Co., c2002: p. 211-213 Rahman, M. Shafiur. Food preservation by freezing. In Handbook of food preservation. Edited by M. Shafiur Rahman. New York, Marcel Dekker, c1999: p. 259-284.

For more print resources...
Search on "cold storage," "cookery frozen foods," "frozen foods," or "home freezers" in the Library of Congress Online Catalog.

Example of freezer burn on hamburger.

Refrigerator/Freezer. From Food Safety and Inspection Service, United States Department of Agriculture Web site.

"Old Man Winter comes to the refrigerator." Prints & Photographs Division, Library of Congress.

Cutting meat prior to freezing. Prints &
Photographs Division, Library of Congress.

New refrigerators no longer use chlorofluorocarbons which deplete Earth’s ozone layer. From NIST Web site.

Packing meat to be frozen.  Prints &
Photographs Division, Library of Congress.

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