Anything kept in a refrigerator has a limited life expectancy, but a properly maintained unit is invaluable for keeping food fresh.
Maintaining proper temperature can be a challenge, particularly as the unit ages, but a little detective work can help you determine if your refrigerator temperature is too high, too low or just right.
Optimum temperatures
No universal “best temperature” exists for all refrigerators, but a standard range has been recommended. Because liquid freezes at 32ºF, a refrigerator should usually have a minimum temperature of 34ºF. Since bacteria grow much faster at 40ºF degrees or higher, a refrigerator should typically be set at a maximum temperature of 38ºF.
Did you know? According to the USDA Food Safety and Inspection Service, bacteria grow most rapidly in the temperature "danger zone," a range between 40ºF and 140ºF that allows bacteria to double in as little as 20 minutes. Any food left to sit in this range for more than 2 hours should be thrown away.
Tip: For an easy-to-use shelf life guide, visit StillTasty.com.
How to know if your refrigerator is too cold
A refrigerator cools on an ongoing basis as needed by the unit. In some instances, the temperature is simply set too low. Or, visual cues may point to a refrigerator that is colder than desired, despite being set at the recommended level. Food that is too cold may change in consistency. If this happens, you may need to warm up the food in order to eat it or use it in certain recipes.
Look for these obvious signs:
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Food that is extremely cold to the touch, or beverages and other liquids that are partially or completely frozen, particularly if they’re near the back of the unit. Cold liquids are typically acceptable, but ice can be a sign that an adjustment is required.
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A refrigerator temperature below the recommended minimum. Moving a refrigerator thermometer around to different parts of the refrigerator can give an indication of warmer or colder spots, which could also help you to detect air leaks.
How to know if your refrigerator is too warm
Cold air is lost each time the refrigerator door is opened or if the unit isn’t properly sealed.
Improper sealing around the door can become a problem as the refrigerator ages and gaskets become brittle or warped.
Try this test of your refrigerator's gaskets: Place a piece of paper or a dollar bill between the closed door and the refrigerator frame. If you can pull it out easily while the door is closed, it’s time to replace the seal. Arrange for the help of a repair professional or see our step-by-step guide to gasket replacement.
If the refrigerator is left open for too long or is unable to cool to the proper temperature, the internal temperature may be too high. If the problem isn’t remedied, food spoilage can be accelerated, which can lead to a health hazard. In addition, food may not taste the same or may change in texture.
Look for these more obvious signs:
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Food removed from the refrigerator not feeling quite as cold to the touch. This is a subjective measure, but it may be particularly noticeable with beverages.
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A higher refrigerator temperature displayed on the thermometer.
For possible reasons why your refrigerator has lost its cool, see our guide to a refrigerator not cooling.
Note: Many refrigerators have beverage holders in the door, but certain liquids—such as milk—stay fresher when stored toward the back of the unit.
How to adjust the temperature of your refrigerator
Adjusting refrigerator temperature is typically a simple task of sliding an indicator or turning a knob. Modern units usually have digital readouts and pushbuttons. Most refrigerators have temperature gauges with displays or numerical listings.
Adjust the temperature as recommended by the owner’s manual or according to the standard range. Changing the temperature by just 1 degree at a time may be sufficient if an adjustment is necessary.
Remember that turning the temperature up or down might require some time to take effect. Some units can take up to 24 hours to stabilize at a new temperature. Some experimentation over a period of days may be required in order to find an acceptable refrigerator temperature.
Tips:
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Avoid storing items such as boxes of cereal and bags of chips on top of your refrigerator. Doing so can keep some of the heat from escaping.
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Keep your refrigerator away from heat sources such as the oven or dishwasher. Refrigerators work best in a room-temperature environment.
