When the power goes out, the food in the freezer will start to thaw, and its safety and quality will be compromised. The length of time the food can stay in the freezer before it needs to be thrown away depends on various factors, such as:
Temperature: If the freezer remains closed, the food will stay frozen longer. However, if the freezer is opened frequently, the thawing process will accelerate.
Type of freezer: Chest freezers typically keep food frozen longer than upright freezers during a power outage.
Food type: Some foods freeze and retain their quality better than others. For example, meats and high-water-content items tend to degrade faster than fruits and vegetables.
Amount of food: A full freezer will stay colder longer than a partially filled one.
Generally, if the power outage is brief (a few hours) and the freezer remains closed, the food should still be safe to consume. However, if the power outage lasts longer, the food will gradually thaw, and you'll need to take the following guidelines into account:
If the food still contains ice crystals and feels as cold as if it were refrigerated, it is safe to refreeze. This indicates that the temperature in the freezer didn't rise significantly.
If the food has thawed but remains below 40°F (4°C), you can cook and consume it immediately. Don't refreeze partially thawed food, as it may lead to a loss of quality and potentially unsafe conditions.
If the temperature inside the freezer rises above 40°F (4°C) for more than two hours, it's best to discard all perishable items, such as meat, poultry, fish, dairy products, and leftovers. These items can quickly develop harmful bacteria when kept at higher temperatures for an extended period.
Items like ice cream may not be safe to consume after thawing, as they can easily be affected by temperature fluctuations and may develop ice crystals or become grainy.
To summarize, the general rule of thumb is to discard any perishable food that has been exposed to temperatures above 40°F (4°C) for more than two hours during a power outage. When in doubt, it's safer to throw out potentially hazardous food items to avoid the risk of foodborne illnesses.