Refrigerators, Freezers, and Perishable Foods

What to Do When the Power Goes Out

The refrigerator and the freezer in your refrigerator are connected. To keep the freezer cold for the longest amount of time, set the refrigerator to the warmest temperature when you are anticipating a power outage.

When the power goes out do not open the refrigerator or freezer unless absolutely necessary.

Order for using refrigerated and frozen foods:

  1. Leftovers and highly perishable refrigerated foods such as milk, poultry, and meat
  2. Less perishable refrigerated foods
  3. Food in a refrigerator freezer
  4. Food in a free-standing freezer

When should I move food from the refrigerator to a cooler?

Move food out of the refrigerator if it looks like the power outage will be for more than 4 hours. Keep a thermometer in the cooler to make sure the temperature is staying at 40o F or below. If you don’t have room in coolers for everything, put the most perishable foods in first using the guidelines above and those below. Coolers are available that are insulated well enough to keep food cold for 5 days in outside temperatures up to 90o F.

How long will my refrigerator and freezer keep food cold/frozen if I don’t open them?1

  • A full chest freezer – 3 to 4 days.  The temperature should maintain ice crystals and should be at or below 5o F.
  • A full upright freezer – 2 to 3 days.  The temperature should maintain ice crystals and should be at or below 5o F.
  • A full refrigerator freezer – 1 to 2 days.  The temperature should maintain ice crystals and should be at or below 5o F.
  • A closed refrigerator – 4 to 6 hours – longer if you put ice in the refrigerator.  The temperature needs to stay below 40o F.  Be aware that newer refrigerators may keep food below 40o F for a much longer time than 4 to 6 hours.  Keep a thermometer in your refrigerator and check the temperature when you open it.

If you have a generator, run the refrigerator for 30 to 60 minutes every 4 to 5 hours to maintain temperatures below 40o F.

What kinds of food can be kept unrefrigerated and for how long? 

Uncut raw fruits and vegetables will keep several days.

Jam, jelly, relish, BBQ sauce, taco sauce, soy sauce, Hoisin sauce, mustard, catsup, olives, pickles, vinegar-based salad dressings, bottled marinade, fruit juice, canned fruit, butter, margarine, hard cheese, and processed cheese can be kept above 40o F for 2 to 3 days.2

Some foods can be kept unrefrigerated if it is understood that they will get stronger in flavor – foods such as yogurt, soft ripened cheese like Brie, and cream cheese. Milk and buttermilk will sour faster above 40 degrees. Any food with unusual smell, color, or texture should be discarded.

When should I discard refrigerated food?

If perishable food has been above 40o F for more than 2 hours or if any food has an unusual smell, color, or texture discard it. Perishable foods would include fresh meat, poultry, lunch meat, hot dogs, leftovers, and prepared foods such as pasta and potato salads.

Mayonnaise, tartar sauce, and horseradish should be discarded if above 50o F for more than 8 hours.3

If you have an ice dispenser in the refrigerator door, check the tray periodically for water. The ice will begin to melt and water may drip into the tray.

Factors affecting how long food will stay frozen if you leave the freezer door shut 4:

•Amount of food in the freezer. Food in a full freezer will stay frozen twice as long as food in a freezer that is only half full. Keeping containers of ice in a partially filled freezer will help keep other foods in the freezer frozen longer.
•Kind of food. A freezer full of meat will stay cold longer than a freezer full of baked goods.
•Temperature in the freezer before it stopped. The colder the food, the longer it will stay frozen.
•Amount of freezer insulation. A well-insulated freezer will keep food frozen much longer than one with little insulation.
•Size of the freezer. The larger the freezer, the longer the food will stay frozen, especially if the freezer is full.

If the freezer is half full, food will remain frozen for half the time it will if the freezer is full.

If your freezer will be off longer than the time the food will remain frozen, you can extend that time by several methods:

  1. Wrap the freezer with crumpled newspapers and then blankets. Do not cover the air vents in case the freezer starts running.
  2. Consolidate the food inside the freezer and put sheets of double reflective insulation over it to keep food cold longer. Lock the door to make sure it stays closed.
  3. Use dry ice. Use 2-1/2 to 3 pounds of dry ice per cubic foot of freezer space. More will be needed in an upright freezer so that dry ice can be placed on each shelf. Place heavy cardboard over packages of frozen food; put the dry ice on top of the cardboard OR wrap dry ice in several layers of newspaper or paper bags. Keep the freezer closed. Be careful when using dry ice; wear gloves so that it doesn’t burn your hands. Keep the room ventilated. Dry ice will keep temperatures low for 2 to 3 days.
  4. Run the freezer on a small generator for 30 to 60 minutes twice a day.

Freezer temperatures at or below 5o F should maintain ice crystals. If ice crystals remain in food, it is usually safe to refreeze it (except for ice cream and frozen yogurt) although there will be changes in the texture, flavor, and color and the nutritional value may be lower. Food that has thawed but is still cold (40o F or below) should be cooked and eaten or cooked and frozen. Food that has thawed and has any unusual smell, color, or texture should be discarded. Food that has been above 40o F for more than 2 hours should be discarded except for thawed frozen vegetables which can be held for up to 6 hours above 40o F.5

BE SURE TO PRINT OUT THIS INFORMATION FOR REFERENCE

  1. Kathleen Purvis, “Keep Your Cool When the Power Goes Out,” McClatchy Newspapers ↩︎
  2. Texas Cooperative Extension, the Texas A&M University System ↩︎
  3. USDA Food Safety and Inspection Service, A Consumer’s Guide to Food Safety: Severe Storms & Hurricanes ↩︎
  4. Colorado State University Extension Service, If your freezer stops ↩︎
  5. USDA Food Safety and Inspection Service, A Consumer’s Guide to Food Safety: Severe Storms & Hurricanes ↩︎