The rules that matter
- Keep the doors shut. Unopened, a fridge stays cold for about 4 hours and a full freezer for up to 48 (24 if half-full). Every peek lets the cold out.
- Under 4 hours? You're fine. A power cut shorter than about 4 hours is unlikely to affect the safety of your food if the doors stayed closed.
- The 4-hour rule for the risky stuff. Meat, fish, eggs, dairy, cooked leftovers and cut fruit or veg: throw them out once they've been above 4°C for more than 4 hours.
- Ice crystals = still safe. Frozen food that still has ice crystals can be refrozen or cooked. Fully thawed high-risk food that sat warm has to go.
- When in doubt, throw it out. Never taste food to check if it's safe. Odd colour, texture or smell - bin it.
The decision table
| Situation | Verdict |
|---|---|
| Cut shorter than 4 hours, doors kept closed | Everything fine |
| Meat, fish, dairy, eggs, leftovers above 4°C for 4+ hours | Bin them |
| Frozen food with ice crystals remaining | Refreeze or cook |
| Fully thawed meat or fish, sat warm | Bin it |
| Butter, hard cheese, unopened juice, bread, whole fruit | Generally fine |
| Anything with an odd smell, colour or texture | Bin it, never taste-test |
Make the next cut cheaper
- Keep the freezer full. Even bottles of water improve how long it holds.
- A fridge thermometer turns guesswork into a reading: under 8°C, chilled food is holding.
- During a live cut, check the outage map first. If your whole town is out and restores are already appearing, the fridge maths usually stays on your side.
Common questions
How long does food last in the fridge without power?
About 4 hours, provided the door stays closed. After that, high-risk food such as meat, fish, dairy, eggs and cooked leftovers that has been above 4°C for more than 4 hours should be thrown away.
How long does a freezer last in a power cut?
A full freezer keeps food frozen for up to 48 hours if unopened, and around 24 hours if half full.
Can I refreeze food after a power cut?
Food that still contains ice crystals or has stayed at 5°C or below can be refrozen or cooked. Fully thawed high-risk food that has been sitting warm should be discarded.