Food freezes if the temperature in a refrigerator drops too low. Foods such as milk, eggs and lettuce undergo undesirable changes when frozen, and other foods need to be thawed prior to use when they are frozen. The ideal refrigerator temperature is between 34 and 40 degrees Fahrenheit.
If the temperature in a refrigerator is too high, bacterial growth on food accelerates, causing food to spoil more quickly. Using a refrigerator thermometer allows users to monitor the interior temperature of the refrigerator to maintain optimal food storage and preservation.
To maintain the safety of refrigerated foods, in addition to keeping the refrigerator at the correct temperature, there must be adequate space between containers to allow the cold air to circulate. Storing foods in air-tight or covered containers maintains flavor and discourages the growth of mold. Cleaning up spills quickly and thoroughly prevents the growth of bacteria. Checking for expiration dates and discarding spoiled foods on a regular basis prevents people from accidentally ingesting tainted food that makes them ill.
Two hours is the maximum amount of time that it is safe to leave perishable foods unrefrigerated, so newly purchased groceries and any leftovers from meals need to be refrigerated as soon as possible.