How long does food last in a power cut?

Links to Amazon are affiliate links. As an Amazon Associate I earn from qualifying purchases. What that means.

• Under 4 hours: don’t worry. Food in the fridge and freezer is unlikely to be affected.
• Fridge: stays cold for up to 4 hours if you keep the door shut.
• Freezer, full: stays frozen for up to 48 hours.
• Freezer, half full: up to 24 hours.

These are estimates and depend on the appliance and how warm the room is. They all rely on one instruction, which is to keep the doors closed. Every look inside costs you time. Decide what you want before you open it, like a bank robber.

The 8°C rule

In normal life a fridge should be at 5°C or below. In a power cut, the FSA says food is fine while the fridge stays under 8°C. Once it reaches 8°C, eat anything that needs refrigeration within 4 hours, and after that, bin it.

You can only know this with a fridge thermometer, which costs a few pounds and is the cheapest insurance on this site.

What to eat first

The FSA’s order, which is also common sense:

1. Food from the fridge
2. Frozen food that has defrosted and doesn’t need cooking
3. Fresh food kept at room temperature
4. Tins, jars and dried food

Offer the neighbours what you can’t get through. A defrosting freezer has started more street parties than the Jubilee.

It’s cold outside. Can I use that?

Yes, and the FSA says so. If it’s below 8°C outside you can store chilled food out there, in a sealed box, somewhere clean and dry, out of the sun and away from animals. A British winter is, for once, pulling its weight.

When the power’s back

• Frozen food that’s still solid is fine. Anything that has defrosted shouldn’t go back in raw. Keep it in the fridge, cook it within 24 hours, and then you can freeze the cooked dish.
• Anything from the fridge that’s been above 8°C for more than 4 hours goes in the bin. Don’t sniff it and gamble. Smell tells you nothing about the bugs that matter.
• Be stricter for anyone who’s pregnant, elderly, very young or unwell.

Making it last longer

• A full freezer holds its cold far longer. Fill the gaps with bottles of water, three-quarters full. They become ice blocks, and later, cold drinking water.
• Know what’s in there. A list on the door means fewer openings.
• Cover it. A duvet over a chest freezer adds hours. Keep the vents at the back clear once power returns.
• A power station from about 1,000Wh will run a typical fridge-freezer through a night. See power stations by budget and the runtime calculator.

Worth having before the next cut

Source: Food Standards Agency, food safety in a power cut. This applies to England, Wales and Northern Ireland; Food Standards Scotland gives matching advice.