The length of time food will stay safe in an unplugged refrigerator or freezer that has lost its cooling ability but has not yet warmed up enough to cause spoilage can vary depending on several factors, including the ambient temperature, the type of food, and the initial temperature of the refrigerator or freezer.
In general, a refrigerator will start to warm up relatively quickly once it's unplugged, especially if the ambient temperature is warm. The United States Department of Agriculture (USDA) recommends that perishable foods (such as meat, poultry, seafood, dairy products, and cooked leftovers) be discarded if they have been held above 40°F (4°C) for more than 2 hours. Temperatures above 40°F (4°C) can allow harmful bacteria to multiply rapidly and increase the risk of foodborne illnesses.
For a freezer, the timeframe is a bit longer. A full freezer will generally keep food safe for about 48 hours if it remains closed. A half-full freezer might keep food safe for around 24 hours. Again, this timeframe can be affected by factors like the initial temperature of the freezer, the type of food, and the surrounding temperature.
It's essential to monitor the temperature inside the refrigerator and freezer and use a food thermometer to check the internal temperature of perishable foods. If the temperature rises above 40°F (4°C) in the refrigerator or if the freezer temperature rises above 0°F (-18°C), it's best to discard perishable foods to avoid the risk of foodborne illness.
In case of a power outage or loss of cooling ability, you can take some precautions to help preserve the cold temperature and extend the safe storage time:
Keep the refrigerator and freezer doors closed as much as possible to retain the cold air inside.
Use ice packs or blocks of ice to help keep the temperature low. Placing a bag of ice in the refrigerator and freezer compartments can provide temporary cooling.
Avoid opening the doors unnecessarily to prevent warm air from entering.
If the power outage is expected to last for an extended period, consider transferring essential perishable items to a working refrigerator or freezer at a different location.
Always prioritize food safety, and when in doubt, it's best to err on the side of caution and discard any food that may have reached unsafe temperatures.