Extended outages lasting more than four hours can make food in your fridge unsafe to eat

Odds are, you’re going to experience a power outage at some point in the coming months. If you’re lucky, your lights will quickly flicker back to life — but we all know that’s not always the case.

So, if an outage stretches for hours, when do the good eats in your fridge turn bad? Let’s get an answer from registered dietitian Beth Czerwony, RD, LD, to avoid potential food poisoning.

How long can food in the fridge last with no power?

The clock starts ticking on your refrigerated food when the power goes out, says Czerwony. In general, you can expect a closed refrigerator to keep food safe for about four hours during an outage.

Now, if you open the fridge to grab a snack during the outage … well, you just let cold air out and warm air in to shorten the survival time of perishable items.

“It’s important to keep the fridge door shut to maintain the temperature inside,” she says.

Everything in your fridge typically chills at or just below 40 degrees Fahrenheit (4 degrees Celsius). Temperatures that climb above that level enter what’s ominously referred to as the “Danger Zone.”

Bacteria can grow quickly on perishable food kept at warmer temperatures. And eating spoiled food can lead to some serious tummy trouble.

Can any food be saved?

While some foods deserve to get the heave-ho after four hours, other items in your fridge may be salvageable. (Good news, given that you probably just dropped serious dollars at the grocery store, right?)

Let’s go over what should stay or go.

Refrigerated food that should be tossed after an outage

If an outage extends past four hours, the following foods may be unsafe to eat and should be discarded:

  • Raw or cooked beef, poultry or seafood; soy meat substitutes also should be thrown out
  • Processed meats such as lunch meat, hot dogs and bacon
  • Milk and dairy products like yogurt and sour cream; milk alternatives (such as soy milk) should go, too
  • Eggs and egg-based products
  • Casseroles, soups and stews
  • Cooked pasta, rice or potatoes
  • Fresh pasta
  • Leftover pizza
  • Soft cheeses such as cream cheese, bleu cheese, Brie, Monterey Jack, mozzarella and Neufchatel
  • Shredded cheeses
  • Low-fat cheeses
  • Fresh fruits and vegetables that have been cut; cooked vegetables, too
  • Greens that have been cut or washed
  • A variety of opened condiments, including cream-based dressings, mayonnaise, tartar sauce and horseradish; opened jars of spaghetti sauce, too
  • Opened containers of vegetable juice
  • Opened baby formula

Refrigerated food that can be kept after an outage

The list of food you can safely keep and eat once the power comes back on includes:

  • Hard cheeses like cheddar, Colby, Swiss and provolone; processed cheeses and grated Parmesan and Romano, too
  • Butter and margarine
  • Uncut raw vegetables and fruits, and dried fruits
  • Opened fruit juices or canned fruits
  • Many spreads, including peanut butter, jelly, relish, ketchup and mustard
  • Many sauces, including barbecue, Worcestershire and opened vinegar-based salad dressings
  • Bread and tortillas

What about freezer food?

Food in a fully stocked freezer can stay safe for up to 48 hours during a power outage, says Czerwony. If your freezer is half full, the contents remain safe for about 24 hours.

Again, it’s important to NOT OPEN the freezer door to let any of the cold air escape.

Frozen meat or meals can typically be refrozen if you see ice crystals on the packaging or if it still feels “refrigerator cold” to the touch when the outage ends. The quality of certain foods (such as frozen fruit or vegetables) may diminish with refreezing.

Most items should be discarded if the temperature in the freezer rises above 40 F (4 C) for more than two hours.

What if you’re not sure about the outage length?

If the outage hits while you’re sleeping or away from home, you might not know how long the power has been out. If you’re unsure, check to see if any food feels lukewarm to the touch. (That’s a bad sign, by the way.)

Keeping a thermometer in your refrigerator may help you better determine whether food can be saved, suggests Czerwony. If the thermometer reads about 40 F (4 C), it’s best to open your trash can and start feeding it.

Bottom line?

Now, nobody wants to throw out food, especially if we’re talking about pricey meats. But sometimes, that’s your safest option to avoid food poisoning and the unwelcome symptoms that come with it.

“When in doubt, throw it out,” advises Czerwony. “A sketchy slice of ham isn’t worth the risk.”