How do I know if frozen food has gone bad?

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.

There are several signs to look out for when checking if frozen food has gone bad. Look for grayish-brown leathery spots, which indicate freezer burn. While freezer burn doesn't make food unsafe, it can significantly affect quality. If there's slight freezer burn, you can cut away these areas before or after cooking. However, if the food is heavily freezer burnt, it's best to discard it.

Also, check if the food has been properly wrapped - food not securely wrapped in air-tight packaging is more likely to be compromised. The optimal freezer temperature should be -18°C (0°F) or below to maintain food quality.

Common misunderstanding: If frozen food doesn't look or smell bad, it's safe to eat.

While appearance and smell are indicators of food quality, they are not reliable measures of safety for frozen food. Harmful bacteria and pathogens can be present without altering the smell or appearance of the food. It's crucial to rely on proper storage practices and expiration dates to ensure food safety.

Common misunderstanding: Freezer burn makes frozen food unsafe to eat.

Freezer burn affects the quality and texture of the food, not its safety. It occurs when air reaches the food's surface, causing dehydration and oxidation. While it might make the food less palatable, it's still safe to consume. However, if the quality is severely compromised, it is advisable to discard the affected portions.

What happens if frozen food starts to defrost and then is refrozen?

You should never refreeze defrosted food. If food has begun to defrost (becoming soft with melting ice), it needs to be moved to a fridge for controlled defrosting and used within 48 hours. If the food has fully defrosted and become warm, it must be discarded.

For items like ice cream that must remain frozen at all times, if they've defrosted they need to be discarded immediately - they cannot be refrozen.

Common misunderstanding: Refreezing defrosted food is safe if it hasn't been left out for too long.

Refreezing defrosted food can compromise food safety, as the thawing process allows bacteria to multiply. Even if the food appears fine and hasn't been out for long, the risk of bacterial growth increases. It's essential to cook defrosted food before considering refreezing to ensure safety.

Common misunderstanding: You can refreeze ice cream if it's only partially melted.

Ice cream that has melted, even partially, should not be refrozen. The thawing process can alter its texture and lead to the growth of bacteria, making it unsafe. Once melted, it's best to discard ice cream to avoid the risk of food-borne illnesses.

How long can I keep food in the freezer before it goes bad?

For items like batch-cooked foods, they should be properly wrapped, labeled with the production date, and used within one month. Fresh meat should ideally not be frozen, but if necessary, it should be adequately wrapped, date labeled, and also used within one month.

The key is proper wrapping and storage - food should be portioned out and thoroughly wrapped or stored in adequate containers before freezing. Always label with production dates and any allergen information.

Common misunderstanding: All frozen foods can be stored indefinitely without any loss of quality.

While frozen foods can be stored for extended periods at 0°F or below, their quality can deteriorate over time. Factors such as freezer burn, changes in texture, and flavour loss can occur. It's advisable to use batch-cooked foods and fresh meat within one month to ensure optimal quality.

Common misunderstanding: Properly wrapped frozen food never goes bad.

Even with proper wrapping, frozen food can eventually degrade in quality. Wrapping helps minimize freezer burn and dehydration, but it does not halt the gradual loss of taste and texture over time. It's important to follow recommended storage durations to maintain food quality.

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.

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.

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

If the power goes out, the duration that food will stay frozen depends on not opening the freezer door. If the food remains hard and is covered in ice, it can be transferred to another freezer.

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.