Newswise — Whether you cook all your food for the week on Sunday or have extra food left at the end of a meal—for many families, leftovers are key to solving the problem of "what's for dinner." Meals like pastas, soups, chili, and other home-cooked meals can easily be reheated for lunch at the office the next day or packed in a heat-insulated thermos for kids' lunches.

Some foods like casseroles, chicken salad, and foods with many different spices can even taste better the next day once all the flavors meld together. But in order for your leftovers to keep that "first bite" taste, properly handling of them can help ensure the leftovers you love stay delicious and bacteria-free.

"Leftovers the next day can be a lovely reminder of the meal you shared with loved ones," says food scientist Kantha Shelke, PhD a spokesperson for the Institute of Food Technologists (IFT), and principal of Corvus Blue, a Chicago-based food science and research firm. "They're also a great way to stretch your food budget. Properly handling and storing leftovers can help ensure your family gets the most value and enjoyment out of the food you've prepared."

IFT shares food facts and safety tips for consumers on its website, IFTfoodfacts.org. The organization cites three key areas for handling leftovers safely: proper refrigeration, storage containers and heating.

Shelke offers some tips for managing leftovers:

RefrigerationOf course you know food needs to be preserved in a refrigerator, but does it need to be cooled off first? Your grandmother probably cooled or chilled cooked foods before refrigerating them for a couple of reasons. First, to save energy; hot food would make the fridge work harder. Also, there was a risk of a hot dish breaking when coming in contact with a cold shelf. Modern refrigerators, however, are built to cool hot dishes. Still, chilling food promptly after cooking and then placing in the refrigerator is both safe and energy conscious. The temperature in your refrigerator should be at 40 degrees Fahrenheit (0 degrees Celsius) or lower. It’s best to use an appliance thermometer to make sure you have the correct temperature rather than relying on refrigerator controls and displays.

Generally, food can go in the refrigerator when it’s reached a temperature of 90 to 100 degrees Fahrenheit—the dish should be just warm to the touch. You can chill food in an ice bath or cold water, sit it in front of a fan, or divide it into smaller portions that can be placed into shallow containers. The key is to store leftovers quickly, within two hours of cooking (one hour on hot summer days or in warm climates).

StoringThe debate over dish or disposable wrap is a matter of personal preference. Thin-walled metal, glass or plastic containers that are shallow (no more than 2 inches deep) are ideal for storage. Bags, foil and plastic wrap also work well, especially if you have a piece of food that is large or oddly shaped.

Cooked meat can be stored three to four days in the fridge, while uncooked ground meats, poultry and seafood will last only a day or two. Raw roasts, steaks and chops (beef, veal, lamp or pork) can be refrigerated for three to five days. Casseroles, veggies and similar side dishes, as well as pie, will usually last three to five days.

If you have a lot of leftovers, you may choose to freeze them. Freezing completely halts bacterial activity, so food can stay safe and usable for months in the freezer, versus three to five days in the refrigerator. Most frozen foods will stay safe for several months; recommended storage times are merely for nutritional value and quality. Uncooked meats can last eight to 12 months in the freezer, while frozen cooked meats will begin to lose their flavor after three months. Freezer temperature should be at 0 degrees F (-18 degrees C).

ReheatingWhen it’s time to serve those leftovers again, a thermometer is the best way to ensure food has been heated to a safe temperature. Most foods, especially meats, should be heated to 165F in the center. Bring sauces, soups and gravies to a boil. Never reheat leftovers in crock pots, slow cookers or chafing dishes.

It’s safe to leave steak or other whole cuts of beef or lamb a little bit rare when you reheat them, as long as they were initially cooked at a high temperature to sear the outside only and kill bacteria on the surface of the meat. Whether you use the stove top or microwave to reheat will depend on the type of food. When reheating in a microwave, use a lower power setting to reheat without overcooking.

Source: Kantha Shelke, PhD, CFS, IFT Spokesperson

About IFTThis year marks the 75th anniversary of the Institute of Food Technologists. Since its founding in 1939, IFT has been committed to advancing the science of food. Our non-profit scientific society—more than 18,000 members from more than 100 countries—brings together food scientists, technologists and related professionals from academia, government and industry. For more information, please visit ift.org.