Do you know what the temperature is inside your refrigerator? Do you know what it should be? According to a national survey, less than 60 percent of consumers know the correct temperature for refrigerator food storage. Only 30 percent of consumers have heard that they should use a refrigerator thermometer to monitor the temperature– and fewer than 20 percent of consumers say they actually use one.
Keeping foods at the right temperature is one of the most effective ways to protect your food investment. It helps prevent spoilage and waste and reduce the chances of foodborne illness.
The US Department of Agriculture recommends maintaining a refrigerator temperature of 40º F or below to slow bacterial growth and maintain food quality. Too low a temperature in the refrigerator wastes energy dollars and may cause ice crystals to form on foods. Adjust the refrigerator accordingly to prevent unwanted freezing, such as freezing milk or tender produce.
The recommended freezer temperature is 0 F or lower. At this temperature, bacterial growth will be stopped. However, freezing does not kill most bacteria, nor does it stop flavor changes that occur over time. Though food will be safe indefinitely at 0 F, quality will decrease the longer the food is in the freezer.
A thermometer will help you monitor the temperature of food on a regular basis, but it is also a critical tool during a power outage from winter or summer storms. In the event of an outage, check food temperatures with a thermometer in each freezer and refrigerator. During an outage, do not open the refrigerator or freezer door any more than is necessary. An unopened refrigerator will keep food safely cold for about 4 hours. A full freezer will hold the temperature for about 48 hours (24 hours if half full.) If refrigerator temperatures start to move above 40 degrees, you will know it is time to take action by adding dry ice or moving cold food to a different location.
Refrigerator/freezer thermometers are also great for renters who have older and/or unfamiliar appliances. Monitoring the temperature inside the refrigerator and freezer will help you know if the appliances are working properly.
Most refrigerator/freezer thermometers are either liquid-filled or bimetallic-coil thermometers. Liquid-filled thermometers are the oldest types of thermometers used in home kitchens. As the temperature changes, colored liquid inside the thermometer rises or falls to indicate the temperature on a scale.
Bimetallic-coil thermometers contain a coil made of two different metals with different rates of expansion that are bonded together. The bimetal element is coiled, fixed at one end, and attached to a pointer stem at the other end. As the temperature changes, the pointer will be rotated on a dial to indicate the temperature.
Purchase refrigerator/freezer thermometers in the housewares section of discount, department, appliance, and grocery stores. Think of them as an inexpensive insurance policy against food waste and spoilage. Buy several! Place one in your refrigerator and one in your freezer– and one in each compartment of any additional refrigerators or freezers you may have in the basement or garage. It may be the best $10 to $20 investment you ever make!
For more information about keeping food safe, call the Ellis County Extension Office at 785-628-4930 or see the K-State Research and Extension food safety links at www.ksre.ksu.edu/foodsafety.
Linda K. Beech is Ellis County Extension Agent for Family and Consumer Sciences.