Healthy Eating: Safety with Cooked Food

Cooling and Storing Cooked Foods

Cooked dishes should be eaten immediately, while they are piping hot, or cooled quickly and put in the refrigerator. Dishes – or part-cooked ingredients – should never be kept merely warm because this encourages bacteria to proliferate. Food that has been cooked to be eaten later should be cooled as quickly as possible because bacteria thrive between temperatures of 7°C (45°F) and 60°C (140°F). It must not, however, be put in the refrigerator immediately because this raises the temperature of the refrigerator. The food should be put in a cool place, such as a larder. Ideally, the cooling process should take no longer than 1 hour. Once the food is cool, it can be placed in a sealed container in the refrigerator or in the freezer.

If meats are microwaved, they should be turned during cooking to ensure even and complete cooking. The high heat that micro-waving generates in the meat’s fat molecules can also damage, or oxidize, the fat and fat-soluble vitamins. Essential fatty acids are destroyed by the level of heat generated by microwaving, so foods that contain them, such as oils, seeds and nuts, should not be microwaved.


One of the most common causes of food poisoning is the growth of bacteria in reheated food. Leftover food should be covered and stored in the refrigerator for a maximum of two days, and then cooked until it is piping hot- reaching a temperature of 75°C(167°F) right through.

In terms of conservation of nutrients, microwave reheating is as good as, if not superior to, conventional reheating techniques. When using a microwave to reheat food, follow the instructions in the manual or on the packet, where appropriate, and ensure that the advice on standing times is followed – this allows the heat to reach all parts of the food.

Cooked food should not be reheated more than once (with the exception of pork, which should never be reheated), as repeated heating and cooling destroys nutrients and encourages bacteria to multiply. It is generally healthier and safer to eat leftover foods cold, especially roast meats and cooked fish.