A refrigerator is one of the most important pieces of equipment in the kitchen for keeping foods safe.

Importance of Refrigeration

Refrigeration slows bacterial growth. Bacteria exist everywhere in nature. They are in the soil, air, water, and the foods we eat. When they have nutrients (food), moisture, and favorable temperatures, they grow rapidly, increasing in numbers to the point where some types of bacteria can cause illness. Bacteria grow most rapidly in the range of temperatures between 41°F and 135 °F, the “Danger Zone,” some doubling in number in as little as 20 minutes. A refrigerator set at 41°F or below will protect most foods.

Types of Bacteria in Refrigerated Foods

There are two completely different families of bacteria: pathogenic bacteria, the kind that cause foodborne illness, and spoilage bacteria, the kind of bacteria that cause foods to deteriorate and develop unpleasant odors, tastes, and textures.

Pathogenic bacteria can grow rapidly in the “Danger Zone,” the temperature range between 41 °F and 135 °F, but they do not generally affect the taste, smell, or appearance of a food. In other words, one cannot tell that a pathogen is present.

Spoilage bacteria can grow at low temperatures, such as in the refrigerator. Eventually they cause food to develop off or bad tastes and smells. Most people would not choose to eat spoiled food, but if they did, they probably would not get sick. It comes down to an issue of quality versus safety:  Food that has been left too long on the counter may be dangerous to eat, but could look fine.  • Food that has been stored too long in the refrigerator or freezer may be of lessened quality, but most likely would not make anyone sick. (However, some bacteria such as Listeria monocytogenes thrive at cold temperatures, and if present, will multiply in the refrigerator over time and could cause illness.)

Safe Refrigerator Temperature

For safety, it is important to verify the temperature of the refrigerator. Refrigerators should be set to maintain a temperature of 41°F or below. Some refrigerators have built-in thermometers to measure their internal temperature. For those refrigerators without this feature, keep an appliance thermometer in the refrigerator to monitor the temperature. This can be critical in the event of a power outage. When the power goes back on, if the refrigerator is still 41°F, the food is safe. Foods held at temperatures above 41°F for more than 2 hours should not be consumed. Appliance thermometers are specifically designed to provide accuracy at cold temperatures. Be sure refrigerator/freezer doors are closed tightly at all times. Do not open refrigerator/freezer doors more often than necessary and close them as soon as possible.

Safe Handling of Foods for Refrigerating

Hot food can be placed directly in the refrigerator or it can be rapidly chilled in an ice or cold-water bath before refrigerating. Cover foods to retain moisture and prevent them from picking up odors from other foods. A large pot of food like soup or stew should be divided into small portions and put in shallow containers before being refrigerated. A large cut of meat or whole poultry should be divided into smaller pieces or placed in shallow containers before refrigerating.

Placement of Foods

The temperature in a refrigerator should be 41°F or below throughout the unit, so that any place is safe for storage of any food. Raw meat, poultry, and seafood should be in a sealed container or wrapped securely to prevent raw juices from contaminating other foods

Keeping the Refrigerator Clean

One very important step in keeping your food safe is keeping your refrigerator clean. Wipe up spills immediately — clean surfaces thoroughly with hot, soapy water; then rinse.