Most people hate to throw out food that has not been eaten at the end of a meal. At the same time, improper handling and storage of leftovers is one of the most common causes of food poisoning in the home. However, with care, it is possible to avoid both waste and illness.
The most important thing to remember is that once food has been cooked, it should be refrigerated or frozen within two hours. This includes the time the food is out of the refrigerator or oven before being served and the time it is on the table. If food is left at room temperature for more than two hours, (one hour in hot weather) bacteria can grow to harmful levels, making it unsafe to eat. It cannot be reused safely - throw it out.
Food that has been at room temperature for less than two hours can be stored safely if it is handled properly (an exception is infant food, which should always be thrown out at the end of the meal). Use clean utensils and clean hands, and do not allow food to come into contact with any surface that has not been cleaned. Stuffing should be removed from cooked poultry upon taking it out of the oven and bones removed from meat before serving.
Leftover food should be moved to a new container, not stored in the container it was cooked or served in. Divide large quantities of food into small portions and put them into containers no more than 5 cm deep, to allow them to cool more quickly.
Do not cool leftovers on the kitchen counter. Stirring food with a clean spoon may help it cool, but then it should be covered and put straight into the refrigerator. To promote rapid, even cooling, leave an air space around the container when placing it in the refrigerator or freezer. Ideally foods should be cooled before freezing to preserve the food’s structure.
It is best to eat leftovers within 2 days. Some items may still be safe after 3-5 days but the longer cooked food is stored, the greater the chance of food poisoning. Freeze any leftovers that cannot be eaten immediately, and note the date on the containers.
There are three safe ways to defrost frozen leftovers: in the refrigerator, in cold water or in the microwave. The safest strategy is to plan ahead for slow thawing in the refrigerator. To defrost food quickly, put it in a leak-proof plastic bag and immerse it in cold water. Change the water every thirty minutes.
When reheating leftovers, bring sauces, soups, and gravies to a boil. Heat other leftovers to 75°C throughout. Stir food to make sure that it is properly heated all the way through and always serve piping hot. Do not reheat foods more than once or mix leftover foods with fresh foods. Never taste leftovers of questionable age and safety. If a leftover has been stored for too long, or if it looks or smells peculiar, throw it out!
- Fraser, Angela M. Handling Leftovers. In The Notebook of Food and Food Safety Information, North Carolina Cooperative Extension Service, 1997.
- Griffith, Christopher, Worsfold, Denise and Mitchell, Robert. “Food preparation, risk communication and the consumer.” Food Control, Vol 9, No. 4, pp. 225-232.
- Schaffner, Donald. Handling Leftovers Safely, Rutgers Cooperative Extension.