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The Optimum Temperature for a Refrigerator & Freezer

Refrigerators keep perishable goods fresh and tasty, and efficiently operating freezers can preserve foods almost indefinitely. While most have thermostats that are set at the factory before purchase, they should be periodically checked to be sure they are set at levels that prevent spoilage and food deterioration.

Refrigerator Temperatures

Keeping freezers and refrigerators at proper temperatures preserves food longer.

Household refrigerator temperatures should be maintained between 35 and 38 F to keep foods freshest longest and avert the growth of harmful bacteria. Temperatures higher than 40 F do not protect foods from spoiling, even though they may look, taste and smell fresh and safe for consumption, as pathogenic bacteria is frequently undetectable. If your refrigerator loses electricity due to a power outage or is mistakenly unplugged, foods that have been stored at higher than optimum temperatures for two hours or more should be discarded. Reliable refrigerator thermometers can be purchased at home improvement centers or hardware stores.

Best Freezer Temperatures

The best minimum temperature for a freezer, either freestanding models or those that are part of a refrigerator, 0 F. To be safe, the temperature should never exceed 5 F. If the freezer doesn't have a reliable thermostat or thermometer, use a common outdoor thermometer to check it. You can also test the freezer temperature with a carton of ice cream. A freezer that fails to keep ice cream as hard as a brick is not properly operating or not properly set cannot safely store frozen foods for more than a week.

Refrigerator Food Storage Guidelines

Different types of food have varying preservation requirements. Store the most highly perishable goods like meat, milk and dairy products on the lowest shelf of the refrigerator near the back of the appliance, as this is the coldest area. Never store milk in the door of the refrigerator because this is the warmest part. Use crisper or vegetable drawers to store fruits and vegetables. These drawers are designed to preserve these foods at varying levels of humidity and make them last longer. Avoid storing meat in the crisper drawers because they deteriorate faster in atmospheres with fluctuating temperatures. Because cooked foods spoil faster than fresh ones, discard leftovers after four days.

Freezer Storage

Although the lower temperatures of freezers will preserve foods indefinitely, the quality of frozen foods deteriorates over time. Common frozen food problems include the formation of ice crystals or freezer burn, in which the exterior surfaces of food become discolored or tough. Unless food is vacuum-packed, most of it will suffer from one of these characteristics over time. To deter ice crystal formation and freezer burn, tightly wrap food items in foil or plastic wrap and then place them in plastic freezer bags for double protection. Date freezer storage containers and use their contents as soon as possible for best flavor and texture.

About the Author

Cassie Damewood has been a writer and editor since 1985. She writes about food and cooking for various websites, including My Great Recipes, and serves as the copy editor for "Food Loves Beer" magazine. Damewood completed a Bachelor of Arts in English with an emphasis in creative writing at Miami University.

Photo Credits

  • eggs and milk image by Jeffrey Zalesny from Fotolia.com