How To Keep Food Fresh and Cut Back on Waste After Losing Power, According to an Expert

When you buy fresh produce or a package of chicken thighs, you’re probably just thinking about what recipe you’re hoping to cook with them, and how long you likely have before they spoil. But that mental calculus of how long food is supposed to stay fresh likely doesn’t factor in random disasters, like blackouts or power outages, into the equation.

Alas, there is a considerable chance that you might soon lose power yourself—and risk losing everything you have stocked up in your fridge and freezer—at any time of year, but particularly in times of drastic weather (i.e. sweltering heat in peak summertime, hurricane season, and mid-winter storms).

So, what can you do if this happens to you to minimize how much you have to toss? For starters, keep the settings cool in general. “You want your refrigerator below 40°F, and freezer at or below 0°F before losing power,” says Kelly Jones, RD, a dietitian and food safety expert.

If you anticipate power going out (say you get notified of blackouts or know a storm is on the way), you can adjust your settings so that the fridge and freezer are a few degrees cooler than normal.

But once the power goes out, you’re up against the clock to ensure that your food stays fresh. Here’s what to know about food safety during a power outage—and how to mitigate the worst of the impact.

Food safety during a power outage: Your expert-approved guide

The “temperature danger zone” for food begins above 40°F and goes up to 140°F. This range indicates when bacteria and other microbes are able to quickly multiply and may release toxins into your food. Thus, refrigerated food should be discarded after a maximum of four hours without power, says Jones. You get a little more time in the freezer, though. “Food will last in a half-full freezer roughly 24 hours and in a full freezer, 48 hours,” she says.

Even if you get your power back within those time frames, you should still thoroughly check all food you intend to consume to make sure it’s still safe to eat. “Check to ensure that your food is below 40°F before preparing or consuming it,” Jones advises—you can do this with a standard food or meat thermometer.

That temperature check is extremely important if you are trying to salvage any food, says Jones. “Since toxins, like botulism for example, have no smell or taste, it isn’t safe to rely on those measures to determine food safety,” she says. Taking a food’s temperature is too easy to risk these food borne illnesses, so use a thermometer no matter how fresh the food still smells.

The type of food matters, too. “Animal products and open-bottled beverages are most likely to spoil quickly and are the foods that temperature checks are most important for,” she says. Same goes for leftovers and prepared foods, she says, like soups or cooked vegetables or grains—even if they don’t contain animal ingredients.

Meanwhile, whole fruits and vegetables are the safest outside of the time and temperature windows indicated, so long as they have been stored away from any animal products and there is no chance of cross-contamination.

All that said, Jones says there are some things you can do to help mitigate the damage and buy yourself a bit more time. But again, be sure to check all food before consuming it with a thermometer. And when it doubt, toss or compost it. Better safe than salmonella.

How to keep food fresh for longer during a power outage:

1. Pre-freeze ice packs and water

If you have a feeling that you may lose power, then you should plan ahead. “If you’re expecting a big storm, you can freeze as many gel packs and containers of water as possible in advance so that you can use them to keep food at proper temperature for longer,” Jones says. You can also buy dry ice or bags of ice in advance and store them in the freezer.

Then, when power goes out, transfer your frozen supplies to the refrigerator. You can also keep your ice packs in coolers nearby. “If the power goes out, transfer the food once the refrigerator or freezer has hit its safe temperature limit,” she says.

2. Stock up your freezer

Keep that freezer full if you can. “A full freezer will stay cold up to twice as long as a half-full freezer, so it’s a good idea to freeze whatever you are able to from the refrigerator to extend the safe window of time,” Jones says.

Looking for healthy foods to flesh our your freezer supply? Check out these healthy picks a dietitian loves:

3. Keep a thermometer inside the fridge and freezer

No matter how you’re trying to preserve food, it’s important to keep a well-functioning appliance thermometer inside your fridge, freezer, or even cooler to ensure the interior temperature stays below 40°F. “This way, you can do a quick temp check each time you open your fridge or freezer to actually get food so that you limit the number of times you’re opening and letting cold air out,” Jones says.

4. Keep the doors closed

Most importantly: Once the power goes out, avoid opening the fridge and freezer as much as possible to ensure cool air stays inside. “But, know this doesn’t keep your food safe for very long without additional support,” Jones says. This will keep foods as cold as they can be for as long as possible.

That being said, if it’s been hours and you still have highly perishable foods—like dairy, meat, or poultry—Jones recommends tossing them. The risk just isn’t worth the reward.

Originally published on August 21, 2020 with additional reporting by Betty Gold. 

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