If the power goes out, how long will food stay frozen?

Date modified: 22nd September 2025 | This FAQ page has been written by Pilla Founder, Liam Jones, click to email Liam directly, he reads every email. Or book a demo to see how hospitality businesses use Pilla to manage food safety.

The key is to keep the freezer door closed as much as possible during a power outage. If the food still feels hard and is covered in ice, it's safe to transfer to another freezer unit. If food has started to soften and ice is melting, you'll need to move it to a fridge for controlled defrosting and use within 48 hours.

Remember: Never refreeze food that has defrosted, and if you're unsure about cross-contamination, it's safer to discard the food.

Common misunderstanding: You can refreeze food after a power outage if it still feels cold.

Although the food may feel cold, refreezing it after it has partially defrosted can be risky. The food may not have maintained a safe temperature, allowing bacteria to grow. Refreezing can also degrade the quality of the food.

Common misunderstanding: If the freezer is full, the food will stay frozen for days during a power outage.

While a full freezer can maintain its temperature longer than a half-empty one, the duration is still limited. Typically, a full freezer will keep food safe for about 48 hours, and a half-full freezer for about 24 hours, provided the door remains closed.

What about ice cream and other foods that must stay frozen?

Items like ice cream that must remain frozen for safety reasons need to either be used immediately or discarded if they've started to defrost. These items cannot be refrozen under any circumstances.

Common misunderstanding: Ice cream can be refrozen if it still has ice crystals.

Even if ice cream still has ice crystals, refreezing it is not safe. The texture and safety of ice cream are compromised once it begins to melt, as this can encourage bacterial growth that refreezing will not eliminate.

Common misunderstanding: If ice cream is consumed immediately after it melts, it is safe regardless of how long it's been defrosted.

While consuming melted ice cream quickly can minimise some risks, any period at an unsafe temperature can allow bacteria to grow. It's best to discard ice cream that has melted significantly to ensure food safety.

How can I tell if food has defrosted too much to be saved?

If food is still hard and covered in ice, it's safe to transfer to another freezer. If it's starting to soften but still cold, move it to a fridge and use within 48 hours. However, if the food is soft and warm to touch, it needs to be discarded immediately. For raw meat and poultry that's beginning to defrost, you might be able to use it immediately if appropriate, but never refreeze it.

Common misunderstanding: You can rely solely on smell to determine if defrosted food is still safe to eat.

Relying on smell is not a reliable indicator of food safety. Many harmful bacteria that cause foodborne illnesses do not affect the smell of food. It's important to consider temperature and texture, and when in doubt, discard the food.

Common misunderstanding: As long as defrosted food is cooked thoroughly, it's always safe to eat.

While cooking can kill many bacteria, it does not eliminate all food safety risks. Some toxins produced by bacteria remain even after cooking. Thus, if food has been at an unsafe temperature for too long, it should be discarded regardless of cooking.

UK Official Guidance

USA Official Guidance

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What's the correct temperature for a freezer?

The ideal freezer temperature should be -18°C (0°F) or below to halt all bacterial activity, ensuring food safety and preventing spoilage.

How often should I check the freezer temperature?

You should check and record freezer temperatures twice per day to ensure they are maintained at -18°C (0°F) or below. Regularly recording this data helps in maintaining optimal food safety conditions.

Can I refreeze food that has started to defrost?

No, you should never refreeze food that has started to defrost. Once food begins to defrost, it should either be used immediately or discarded to avoid safety risks.

What do I do if the freezer temperature goes above -15°C?

If your freezer temperature rises above -15°C, follow these steps: 1. Wait one hour and check the temperature again. 2. If it remains above -15°C, move all food to another freezer. 3.

How do I know if frozen food has gone bad?

To determine if frozen food has gone bad, look for these signs: grayish-brown leathery spots indicating freezer burn, improper wrapping, and storage above -18°C (0°F).

Should I defrost the freezer manually or wait for auto-defrost?

If your freezer has an auto-defrost feature, it is recommended to use it as this method is the most efficient at maintaining the freezer.

Can I still serve food with freezer burn?

If there's only slight freezer burn, you can cut away the affected areas either before or after cooking. For heavily freezer-burned food, it is best to discard it due to quality concerns.

How long can I keep meat in the freezer?

Fresh meat should ideally be used within one month of freezing to maintain optimal quality.

What's the procedure if the freezer breaks down?

If your freezer breaks down, you should: 1) Check if the food inside is still frozen solid. If yes, quickly transfer it to another freezer.

How often should I clean the freezer?

You should conduct weekly checks on the freezer's condensers, vents, seals, and lids to ensure they are clean and in good condition.

What should I check during weekly freezer maintenance?

During weekly freezer maintenance, ensure to check: 1. Condensers for cleanliness and unblocked paths, 2. Vents to ensure they are clear of debris and allow proper airflow, 3.

What do the grey spots on frozen food mean?

Grey spots on frozen food, known as freezer burn, occur when air reaches the food's surface, causing dehydration and oxidation.

How can I tell if my freezer is overloaded?

You can determine if your freezer is overloaded by checking for inadequate space around the interior and back of the unit to allow for air circulation.

How do I label frozen food properly?

When labelling frozen food, it's important to include three key pieces of information: the production date, a use-by date (generally one month from production), and the allergens present in the food.