Leftovers. Some people love them. Others not so much. Doggie bags from a restaurant or just extra food from last night’s supper, are all leftovers that need safe storage.

The United States Department of Agriculture recommends storing cooked leftovers no longer than three to four days. These short-but-safe limits are best for both quality and safety. Many consumers do not practice safe leftover storage. In a study by the USDA, one-third of participants said they’d eat leftovers stored longer than four days after cooking.

If a leftover is green, moldy, slimy, or smells bad, obviously you shouldn’t eat it regardless of how old it is.

The food may look fine after four days, but keep-in-mind, that there are some pathogens in foods that you can’t see, smell or taste that can contaminate food and cause life-threatening illness. Foodborne illness can strike anyone, especially young children, pregnant women (it endangers their unborn babies too), older adults, and persons with weakened immune systems.

Another key to keeping leftovers safe is to refrigerate the food within two hours of cooking or being served at a restaurant. Bacteria can multiply rapidly between 40 degrees F and 140 degrees F, so limit the amount of time food is in that “danger zone.” Holding food at unsafe temperatures allows pathogens to multiply to a level that there are enough of them in the food that it could makes someone sick. Once developed, some pathogens cannot be destroyed by cooking and reheating. 

Refrigerator temperatures can slow most pathogen development. Check the temperature of your refrigerator, it should be between 36-38 degrees F. This makes sure the food stays below 40 degrees F. It’s also important not to over fill your fridge, allow air to circulate around the food.

Size matters with leftovers. Cool the food quickly and properly, especially when you have large quantities. Separate food into smaller portions and place in shallow pans or bowls. Let your refrigerator cool leftovers—don’t leave at room temp to cool. Use an ice bath to cool foods such as soups and stews if necessary. Loosely cover when hot to allow the food to cool faster. Once cool, cover in airtight packaging or in sealed storage containers. Not only will it keep bacteria out, but it helps the leftovers retain moisture, whether they’re stored in the refrigerator or the freezer. Covering also prevents leftovers from picking up odors from other foods in the refrigerator.

Most leftovers can be frozen, but don’t wait until the throw-away date to put them in the freezer. Freezing food never makes food better. Be sure to use freezer containers or bags. Label and date these packages. In addition to knowing how old something is, labels help avoid surprises. Once frozen, it’s hard to tell what’s inside the package. Without labels, peaches can look like summer squash or you might get shredded cooked chicken when you’re wanting pork BBQ. Freezing will slow or stop bacterial growth. But when you thaw the food, the growth continues from where it left off. An example: if soup was in the fridge for 2 days before it was frozen, it should be used within 1-2 days after it is thawed. Freezing doesn’t reset the clock.

There’s an app that can help you with leftover safety. It’s called FoodKeeper. The app was developed by the USDA’s Food Safety and Inspection Service with Cornell University and the Food Marketing Institute. FoodKeeper is available for both Android and Apple devices and free of charge.

The USDA has other good references as well. 

Syracuse is a Family and Consumer Science team member and can be reached at N.C. Cooperative Extension, Brunswick County Center 910-253-2610 or by email at Cheryle_Syracuse@ncsu.edu