In a power cut, a full freezer with the door shut stays cold enough for around 48 hours, a half full freezer for around 24 hours. A closed fridge usually holds out for 4 to 6 hours. But the rule that actually counts is not the clock, it is the temperature: the Dutch nutrition centre Voedingscentrum advises that once the fridge goes above 10 degrees, you throw out the vulnerable items such as meat, fish, cooked meats, soft cheese and pre-cut vegetables, and above 15 degrees the yoghurt, milk and opened packets go too. For the freezer: still rock hard? Straight back in. Soft on the outside? Into the fridge and eaten within two days. Fully defrosted? Meat and fish go in the bin. And keep this in mind: if the outage lasts longer than 4 hours, Dutch households are entitled to 35 euros from their network operator, plus 20 euros for every extra 4 hours. Other countries have their own compensation schemes, so it is worth checking what your network operator owes you.
Hello DIYer,
The power goes off. Your first instinct? Pull open the fridge to see whether everything in there is still cold.
Don’t.
Because that is exactly what your freezer and fridge cannot cope with at that moment. Every time you open the door, you tip the cold air out and pull warm air in. And during a long outage, that cold air is literally all you have left.
Below I will tell you exactly how much time you have, how to measure instead of guess, what has to go and what can simply stay, and which bit of preparation takes two minutes and saves you hundreds of euros of food next time the power drops.
Plus something almost nobody thinks about: after a longer outage you are entitled to money from your network operator, and you do not even have to apply for it.
Here we go:
The rules of thumb at a glance
| Situation | How long it stays safe |
|---|---|
| Fridge, door shut | around 4 to 6 hours |
| Fridge, door opened regularly | much shorter, count on 2 hours |
| Freezer full, door shut | around 48 hours |
| Freezer half full, door shut | around 24 hours |
| Freezer nearly empty | 12 hours or less |
| Chest freezer, full | often longer than 48 hours |
A short half hour outage is no problem. Several hours or a whole day is. Source: Voedingscentrum, the Dutch nutrition centre
Important to understand: these are guide times, not guarantees. They depend on how well your appliance is insulated, how full it is, how warm the house is and how often you open the door. An old fridge from 2005 in a kitchen at 24 degrees holds out far less long than a new one in a cool utility room.
Which is why the main message of this article is:
Don’t go by the clock. Measure the temperature.
Why a full freezer lasts twice as long
This is simple physics and it is immediately the handiest tip in this whole article.
Frozen food is stored cold. Every kilo of frozen food in your freezer is a block that has to warm up and thaw before you have a problem, and that takes time. The more mass in there, the longer it takes.
Air, on the other hand, stores almost no cold at all. A half empty freezer is half filled with something that reaches room temperature within an hour.
So: fill the empty space in your freezer with bottles or tubs of water. Plain tap water, in plastic bottles filled three quarters full (water expands as it freezes, so leave room). Those blocks of ice cost you next to no extra energy to keep cold (the compressor is mostly fighting heat leaking in from outside), and they double your margin during an outage.
Bonus: when the power does go, you instantly have a stack of ice blocks to put in the fridge or a cool box.
And bear this in mind: a chest freezer naturally lasts longer than an upright freezer with drawers or a door. Cold air is heavier than warm air and simply sits in the bottom of a chest. With an upright, it pours out every time you open the door, like water out of a bucket.
The most important rule: keep that door shut
Seriously. This is not just a tip, this is the entire strategy.
Every time you open the freezer door during an outage, it costs you a good chunk of your margin. Every time you open the fridge, you replace the air inside completely.
What you do the moment the power goes:
- Open nothing. Seriously. Not even a “quick look”.
- Work out what you are eating tonight from what is sitting outside the fridge. Bread, pasta, tins, fruit from the bowl.
- Still need something from the fridge? Do it once, fast and planned. Make a list before you open, grab everything in one movement, door shut.
- Is it dragging on? Insulate the freezer further. A couple of blankets or duvets over a chest freezer or upright (but not over the ventilation slots at the back once you switch it back on) slows the warming noticeably. Sounds daft, works well.
- Move the most vulnerable food into the freezer if you have to open it anyway. Meat and fish from the fridge, tucked in between the frozen stuff, stay good the longest.
How to measure instead of guess
A cheap fridge thermometer in the fridge and one in the freezer is the best investment you can make. Costs very little, and after an outage you know exactly where you stand instead of having to sniff and hope.
Better still is a min/max thermometer: it remembers the highest temperature reached. Because that is precisely what you want to know. If the power comes back after eight hours, your fridge cools neatly back down to 4 degrees and everything looks fine, even though it hit 14 degrees in the meantime.
The coin trick for your freezer
This one is old, free and surprisingly good. Especially handy when you go on holiday and have no idea whether anything happened while you were away.
- Fill a tub halfway with water.
- Put it in the freezer until it is frozen solid.
- Place a coin on top.
- Put the tub back in the freezer and leave it there.
When you get home, or after an outage, you read it like this:
| Position of the coin | What happened |
|---|---|
| Sitting on top of the ice | Everything stayed frozen. Fine. |
| Halfway down the ice | Partly thawed and refrozen. Be critical. |
| At the bottom of the tub | Fully thawed and frozen again. The food is no longer reliable. |
Important nuance: this is a signal, not an official food safety test. You do not know how long it was thawed, only that it happened. A min/max thermometer gives you better information. But the coin trick costs nothing and is infinitely better than nothing.
What do you throw out? The Voedingscentrum advice
This is the heart of it, and happily the advice is concrete. Measure the temperature and use these thresholds.
Fridge
Above 10 degrees: throw out the vulnerable items. That means:
- raw meat and mince
- raw fish and smoked fish
- cooked and cured meats
- soft cheeses
- pre-cut vegetables and ready-made salads
- ready meals
Above 15 degrees: on top of that, also throw out:
- yoghurt, milk and other dairy
- opened packets such as sauces and soup
What can usually stay:
- vegetables and fruit: judge on appearance and smell
- unopened jars and bottles that you would normally be able to store outside the fridge anyway (most sauces before opening, for instance; check the label)
- hard cheeses (judge them critically)
- eggs: you can still use them, but cooked through properly, not raw in something like tiramisu or a dressing
Source: Voedingscentrum, the Dutch nutrition centre
The reason behind it: bacteria multiply fast above roughly 7 degrees. The longer a product sits in that zone, the greater the chance they have grown to numbers that make you ill. And that is not something you taste or smell. A dangerous portion of chicken often smells perfectly fine.
Freezer
Three situations, three answers:
1. The item is still frozen solid. Straight back in the freezer. No problem. Quality may drop a little (freezer burn, more ice crystals, a softer texture), but it is safe.
2. The outside has gone soft, the core is still frozen. Not back in the freezer. Put it in the fridge and eat it within two days.
3. The item has fully thawed. Vulnerable products such as raw meat, poultry, fish, shellfish, ready meals and dairy go in the bin. Anything else you eat as soon as you can, ideally the same day.
The key rule of thumb for refreezing:
Still rock hard = back in. Gone soft = do not refreeze.
And there is one important exception: anything you have cooked can go back in the freezer. Heating kills off the bulk of the bacteria. So you have four kilos of thawed chicken breast? Fry or boil the lot today, cool it down quickly and freeze it again cooked. That way you still rescue a large part of your stock.
What you never do: refreeze thawed raw meat “just to be safe”. The bacteria that woke up during thawing do not die from freezing. They simply hit pause and pick up where they left off the next time it thaws.
Not sure?
Then bin it. A pack of mince costs a few euros. Food poisoning costs you a week.
And one more time, because it matters: smelling and tasting is not a test. Salmonella, listeria and campylobacter change nothing about smell, colour or flavour.
What you can sort out today for next time
This section is the most valuable part of the article, because an outage always comes at an inconvenient moment.
1. Fill the empty space in your freezer with water bottles. Costs nothing, doubles your margin. Do it today.
2. Put a thermometer in the fridge and the freezer. Ideally a min/max model.
3. Set up the coin trick. Five minutes of work, then it sits there for years.
4. Make sure you have cool boxes and freezer blocks. In an outage longer than half a day, a good cool box with frozen blocks is what saves the most vulnerable part of your fridge. Leaving four to six freezer blocks permanently in the freezer is free insurance.
5. Give your freezer its own circuit. This is the tip that appears in no other article, and it is the most common cause of “the freezer was off and I had no idea”. If your freezer sits on the same circuit as the shed, the garden lights or the socket you plug the pressure washer into, it goes down with them whenever that circuit or the RCD trips. And you only find out after three days away. A freezer on its own circuit, ideally with its own RCD, removes that risk entirely. This is work in your consumer unit, so it is work for someone qualified to do it. Have a registered electrician carry it out if you are not sure what you are doing.
6. Put a smart plug or power sensor with alerts on your freezer. A simple wi-fi plug with energy monitoring sends you a notification when it drops offline. That only works if your router still has power, so put the router on a small UPS if you want to take this seriously.
7. Consider a backup power supply for the freezer alone. More on that shortly, because there are catches.
8. Know where your main switch is and check it first. Before you panic about a whole area being out, look at your own consumer unit. If it is only your house without power and not the neighbours, it is an RCD or a circuit breaker, and you fix that in two minutes.
Backup power for your freezer: what you need to know
A portable power station looks like the perfect solution. Often it is, but do run the numbers first.
How much energy does a freezer need? A modern freezer uses roughly 150 to 350 kWh a year, depending on size and energy rating. That works out at roughly 0.4 to 1 kWh per day. You will find the exact annual consumption on the energy label or the rating plate of your appliance.
Which means a 1 kWh (1,000 Wh) power station keeps an efficient freezer running for roughly one to two days. An old chest freezer with poor insulation draws considerably more.
Watch the start-up load. A compressor briefly draws far more current when it kicks in than while it runs. An appliance that “uses 150 watts” can demand a peak of several hundred watts at start-up. So look at the peak output of the inverter, not just the continuous rating, and choose an inverter with a pure sine wave, because a square wave inverter is not kind to a compressor motor.
And then the setback most people do not expect: if you have solar panels, you still have no power during an outage. The inverter shuts itself down the moment the grid drops. That is a mandatory safety function: without it you would be feeding electricity into a network that engineers are working on. Only with a dedicated backup supply, or a home battery with a backup power function, can you keep running during an outage, and that is a separate installation that has to be fitted on top. Solar panels on the roof are not backup power.
Your right to compensation: two routes
This is where most people leave money on the table.
1. Your network operator’s compensation scheme
As a small consumer (a connection up to and including 3×25 amps, which is the normal domestic connection) you are entitled in the Netherlands to a fixed payment after a long outage:
- 35 euros for a power cut of 4 to 8 hours
- plus 20 euros for every additional 4 hours
The network operator transfers that amount within 6 months of the outage. You do not have to apply for it, it should land in your account automatically.
Source: ACM, the Dutch authority for consumers and markets
Living elsewhere? Check what scheme your own network operator runs. The amounts differ, the approach is the same.
Practical tip: write down when the outage started and when the power came back. If the money has not arrived after a couple of months, those two timestamps are what you take to your network operator. The Dutch consumer service ACM ConsuWijzer even has a template letter for it.
2. Your home contents insurance
Plenty of home contents policies cover spoiled fridge and freezer contents after a power cut. The conditions vary quite a bit between insurers:
- there is often a minimum duration for the outage, usually somewhere in the range of 4 to 12 hours
- there is usually a maximum payout attached, which differs sharply per policy
- what is covered is the contents of fridge and freezer, not other damage
Check your policy wording under a heading like “damage caused by power failure” or “spoiled refrigerated food”.
What you have to do to keep this workable: take photos. Before you throw anything away, lay the contents out on the worktop, take a few clear photos and note the length of the outage. Without evidence it gets awkward. And hang on to receipts for bigger purchases if you have just frozen half a cow.
Special cases
Medicines in the fridge. Insulin and many other biological medicines have strict storage temperatures. Do not sit there reasoning it out yourself. Phone your pharmacy and ask what to do with this specific medicine after this specific temperature exposure. They have guidance for exactly that.
Breast milk. Treat it as the most vulnerable product you own and follow the advice of your health visitor or midwife.
Planned works. Got a letter saying the power will be off for a day because of network maintenance? Then you have all the time in the world. Freeze extra water bottles in the days beforehand, eat the fridge empty, get freezer blocks ready and move the most vulnerable items into the freezer.
Long holidays. Set up the coin trick, make sure your freezer is on its own circuit, and ask a neighbour to send you a message if the street loses power.
Winter storms and forecast extreme weather. As soon as an amber or red warning comes in with a chance of a long outage: fill that freezer with water bottles and charge up your power station. It costs you twenty minutes and it is the best twenty minutes you spend that day.
When the power is back: the step-by-step
- Look at the thermometer first, before you start sorting. With a min/max thermometer you read off the peak temperature.
- Freezer first. Feel which packs are still rock hard (they stay), which are soft on the outside (into the fridge, eaten within two days) and which have fully thawed (vulnerable ones go, the rest gets cooked today).
- Fridge next. Use the 10 degree and 15 degree thresholds above.
- Photograph everything you throw away, for the insurance.
- Cook the rescue operation. Anything thawed but still good: cook it today and freeze it again cooked if you want.
- Note the length of the outage for the compensation scheme.
- Clean the fridge if anything has leaked. Drips from raw meat on a shelf are a contamination source that sits there for weeks.
- Check that everything is running again. Especially with a standalone freezer in the garage or shed: check that it actually kicks back in and that the plug is still properly in the socket.
The seven mistakes in a power cut
1. Opening the door to have a look. The most expensive reflex there is.
2. Trusting the clock instead of the thermometer. Four hours in a cool utility room is a completely different thing from four hours in a kitchen at 25 degrees.
3. Using smell and taste as a test. Does not work for the most dangerous bacteria.
4. Refreezing thawed raw meat. Don’t. Cook it first, then freeze.
5. Binning everything in a panic. A large part is usually perfectly fine. Measure, sort and rescue what can be rescued.
6. Keeping no evidence. No photos, no times, no compensation.
7. Thinking your solar panels will save you. Without a dedicated backup supply they deliver nothing during an outage.
Frequently asked questions
How long does a freezer stay cold without power?
A full freezer with the door shut holds out for around 48 hours, a half full one for around 24 hours, and a nearly empty one for considerably less. A chest freezer naturally does better than an upright, because the cold air does not fall out when you open it. These are guide figures: how well the appliance is insulated, how warm the room is and how often you open the door all make a real difference. Which is why a thermometer inside is far more reliable than the clock.
How long does food stay good in the fridge during a power cut?
Count on around 4 to 6 hours with the door shut. If you open the door regularly, it is closer to 2 hours. What decides it is the temperature: above roughly 7 degrees bacteria multiply fast. Once the fridge goes above 10 degrees, the Voedingscentrum advises throwing out vulnerable items such as meat, fish, cooked meats, soft cheese and pre-cut vegetables. Above 15 degrees, dairy and opened packets go too.
Can I refreeze thawed meat?
Raw meat that has fully thawed: no. The bacteria that became active during thawing do not die from freezing, they simply hit pause. If the meat is still frozen solid, it can go straight back in the freezer. If only the outside has softened, put it in the fridge and eat it within two days. And the important exception: if you cook or fry the thawed meat through first, you can freeze it again once cooked.
How do I know whether my freezer defrosted while I was away?
The coin trick: freeze a tub half full of water solid, put a coin on top and pop it back in. If the coin is still sitting on top when you get home, everything stayed frozen. If it has sunk or is lying at the bottom, the contents thawed (at least partly) and refroze. It is a signal, not an official food safety test, because you do not know how long it was thawed. A min/max thermometer that remembers the highest temperature gives you better information.
Do I get money back after a power cut?
Yes, for an outage longer than 4 hours. As a small consumer with a connection up to 3×25 amps in the Netherlands, your network operator pays 35 euros for an outage of 4 to 8 hours, plus 20 euros for every extra 4 hours. That amount should appear in your account automatically within 6 months, with nothing required from you. Other network operators run their own schemes, so it is worth a quick check. On top of that, plenty of home contents policies cover spoiled fridge and freezer contents, usually from an outage of 4 to 12 hours and up to a maximum that differs per policy. Note the start and end time of the outage and take photos before you throw anything away.
Do my solar panels work during a power cut?
No, not without extra kit. The inverter shuts itself down automatically the moment the grid drops. That is a mandatory safety function: if it carried on, you would be feeding electricity into a network that engineers are working on. If you want to keep running during an outage, you need a backup supply, for example a home battery with a backup power function or an inverter with a separate backup output. That is a separate installation that has to be fitted on top.
Can I run my freezer off a power station?
Yes, as long as you watch two things. Look at the energy first: a modern freezer uses roughly 0.4 to 1 kWh per day, so a 1 kWh power station gets you roughly one to two days. The exact annual consumption is on your appliance’s energy label. Then watch the start-up load: a compressor briefly draws far more when it kicks in than while it runs, so check the peak output of the inverter and pick one with a pure sine wave.
What is the first thing I should do when the power goes off?
Work out whether it is you or the street: have the neighbours lost power too? If not, check your consumer unit for a tripped RCD or circuit breaker. If it is an area-wide outage, keep the fridge and freezer shut and work out what you are eating tonight from whatever is sitting outside the fridge. Note the time the outage started, because you will need that later for the compensation scheme. And if it is going to drag on: put blankets over the freezer and move the most vulnerable items from the fridge in among the frozen food.
A freezer that lasts 48 hours instead of 24 is not a matter of luck, it is a matter of insulation, how full it is and where the appliance stands. The same goes for the rest of your house: wherever heat leaks out, money leaks out. In the Energie Verpulveraar I walk you past the energy guzzlers in your home and the measures in order of return, with the numbers alongside so you can work out for yourself what it saves in your situation.
Do yourself a favour. Fill that empty space in your freezer with water bottles tonight. Five minutes of work, and it literally doubles the time you have when things go wrong.
Regards from Fred Schouten, DIYer through and through
PS: Drop that coin in as well. Especially if you are away for two weeks in summer. You do not want your first meal back from holiday to be a load of chicken that sat at ten degrees for three days and then froze neatly back up again.