Refrigerator Temperature Guide
Keeping food cold is partially a matter of conveience. None of us would want to go without chilled drinks, for example. But refrigeration is mostly about safety. Nearly all foods contain bacteria that can cause human illness or food spoilage if they're allowed to flourish. Refrigeration kills bacteria or slows their growth rate, which keeps food safe and edible for much longer periods of time. The refrigerator temperature guide below will help you to understand bacteria and the best temperatures for food safety.
Bacteria and refrigerator temperatures
Refrigerated food contains two types of bacteria:
• pathogenic bacteria that cause food-borne illness
• spoilage bacteria that cause food deterioration
When provided with food, moisture, and warm temperatures, bacteria grow rapidly. In the case of spoilage bacteria, this growth causes a very noticeable change. Food develops bad or rotten odors, and undergoes changes in taste and texture. Pathogenic bacteria are much more insidious. They generally do not affect the taste, smell, or appearance of food.
Bacteria grow fastest in temperatures of 40 to 125 degrees F. This temperature range is often called "the danger zone," because food left in such temperatures for more than two hours is unsafe to eat -- even if it appears edible.
Freezing food at a temperature of 0 degrees F or colder will make bacteria totally inactive. However, freezing is also inconvenient. Thawing can take hours, and some foods such as fruit lose taste and texture when frozen. Refrigeration offers the best combination of convenience and safety.
What is the best refrigerator temperature?
The safest refrigerator temperature range is between 35 and 38 degrees F, and no higher than 40 degrees. Such temperatures will keep food safe from nearly every type of pathogenic bacteria while permitting the slow growth of spoilage bacteria. An appliance thermometer is the best way to monitor refrigerator temperature.
Even within that optimum refrigerator temperature range, different types of food will have different preservation needs. Crisper drawers should be used if available, because vegetables last longer in humid conditions and fruits in drier conditions. Never store perishable foods in the refrigerator drawer -- especially meat. Temperatures fluctuate much more readily in that area and will accelerate spoilage.
Refrigerator storage times
Because of the slow growth of spoilage bacteria, even refrigerated foods eventually go bad. For example, cooked leftovers should be kept no more than four days at regular refrigerator temperatures. Here's a quick guide listing maximum storage times for basic foods kept at a safe refrigerator temperature:
• fresh eggs: 3 to 5 weeks
• cooked egg dishes: 3 to 4 days
• food salads (tuna, chicken, etc.): 3 to 5 days
• ground beef, turkey, veal, pork, or lamb: 1 to 2 days
• cooked ham slices: 3 to 4 days
• opened luncheon meats: 3 to 5 days
• bacon: 7 days
• hard sausage: 2 to 3 weeks
• cooked casseroles: 3 to 4 days
• soups and stews: 3 to 4 days
• steaks, chops, roasts: 3 to 5 days
• chicken or turkey: 1 to 2 days
• fresh fish and shellfish: 1 to 2 days