How Long Does Food Keep in Freezer Without Power

Power cut? Learn how long food stays safe in your freezer, when to refreeze, and how to handle frozen food during and after a power outage.

During a power cut, a full freezer will usually keep food safely frozen for up to 48 hours—about 24 hours if it’s half full. The key is to keep the freezer door shut as much as possible to maintain the cold temperature.

Insulated freezers work like a cooler. The more packed it is, the longer it stays cold. So if the power goes out, your best option is to leave the door closed and wait it out before making any decisions.

Steps You Can Take

Here’s how to maximise food safety during a power cut:

  • Don’t open the freezer unless absolutely necessary.

  • Group frozen food together to keep cold concentrated in one area.

  • Add bags of ice or frozen water bottles if the outage is planned or expected.

  • Cover the freezer with blankets (but not blocking ventilation) to insulate it further.

If you know a power cut is coming (e.g., planned maintenance), consider pre-freezing bottles of water and filling empty space to extend cooling time.

Frozen Food Does Not Last Forever

Even without a power cut, frozen food has a shelf life. Over time, quality and texture degrade. Here’s a rough guide:

  • Meat: 4–12 months

  • Bread: 3–6 months

  • Vegetables: 8–12 months

  • Cooked meals: 2–3 months

Freezer burn doesn’t mean food is unsafe, but it can make it taste unpleasant. Use older items first and label everything with dates.

Can You Eat Frozen Food Past the Expiration Date?

Yes, if it has remained continuously frozen, food can be safe to eat past its best-before date. The quality might not be great, but it won’t necessarily harm you.

However, if the freezer temperature has risen above -18°C, bacteria can start to grow. That’s why it’s important to assess the food carefully after a power cut.

Can You Refreeze Food After It Has Defrosted?

Only in some cases. If the food still contains ice crystals or has stayed below 5°C, it’s generally safe to refreeze. But the texture and taste may suffer.

If the food has thawed completely and has been sitting for hours at room temperature, do not refreeze—it could be unsafe to eat.

What Should You Do with Your Freezer During a Power Cut?

During a power cut:       

  • Keep the door closed

  • Move food to a cooler with ice packs if the outage lasts more than 24 hours

  • Track how long the power has been off

  • Don’t use candles or open flames near the freezer

If your freezer is not very full, consolidate food into one section or transfer to a neighbour’s freezer if they have power.

What Should You Do With Your Freezer After a Power Cut?

Once power returns:

  • Check the temperature (if you have a freezer thermometer). If it’s still below -18°C, your food is likely safe.

  • If not, inspect items for ice crystals or firmness.

  • Discard anything with a strange smell, colour change, or signs of spoilage.

  • Clean the freezer if any food leaked during defrosting.

Examine Frozen Food Carefully: If There Are Still Ice Crystals, Then It Will Still Be Safe to Eat

This is a good rule of thumb. Ice crystals mean the core temperature never rose too high. It’s especially important for:

  • Meat

  • Poultry

  • Seafood

When in doubt, throw it out — especially for high-risk foods like dairy, eggs, and cooked meat.

What Food is Safe in a Freezer During a Power Cut?

These foods are more likely to survive a power outage:

  • Raw meat (especially large cuts or sealed packs)

  • Frozen fruit and veg

  • Butter, hard cheese

  • Bread, cakes, pastry dough

Foods in the centre of the freezer tend to stay coldest longest. If you packed your freezer well, there's a good chance much of the food is still usable.

More to Know About How Long Food Lasts in a Freezer Without Power

The 4-Hour Rule (for Fridges)

It’s not freezer-specific, but worth noting: Refrigerated food (not frozen) only stays safe for about 4 hours during a power cut — if you keep the door closed. So, if your freezer has a fridge section, be extra cautious with dairy, eggs, and leftovers stored there.

Factors That Affect How Long Food Stays Frozen

  1. Freezer fullness – A full freezer retains cold better than a half-empty one. Frozen items help insulate each other.

  2. Freezer type – Chest freezers stay cold longer than upright freezers due to better insulation and less air circulation when opened.

  3. Ambient temperature – If it’s hot in the room (e.g. summer or near an oven), your freezer warms up faster.

  4. Age and condition of freezer – Older models or ones with worn seals may not retain cold as well.

Signs That Frozen Food Is No Longer Safe

Even if it looks okay, you should toss frozen food if:

  • It smells off or sour once defrosted

  • There’s evidence of liquid leakage or pooling (especially in meat)

  • Packaging is swollen or split from internal gas buildup

  • There’s no ice or frost left and the texture feels soft throughout

How to Tell if a Freezer Got Too Warm During a Power Cut

If you didn’t see the outage happen, try this trick before the next one:

The Coin-in-a-Cup Test:

  1. Freeze a cup of water solid.

  2. Place a coin on top and keep the cup in your freezer.

  3. If you come back after a power cut and the coin is at the bottom, the freezer completely thawed.

  4. If the coin is still on top or halfway down, your food likely stayed safe.

Emergency Prep Tips

If you live in an area with frequent outages or rural delivery:

  • Keep jugs of water frozen in your freezer to fill space

  • Use freezer thermometers with memory that show high/low temps

  • Keep a small backup generator or power bank to run the freezer temporarily

  • Stock easy-to-inspect items like frozen veg or ready meals to test conditions before checking high-value meat or seafood