Skip to main content
English Cymraeg

How to chill, freeze and defrost food safely

Chilling, freezing and defrosting food properly helps stop harmful bacteria from growing.

Last updated: 12 June 2024
See all updates
Last updated: 12 June 2024
See all updates

Here are our top recommendations on chilling and freezing your food safely: 

  • your fridge should be between 0 and 5°C  and your freezer should be around -18°C  
  • keep chilled food out of the fridge for the shortest time possible during preparation (a maximum of four hours) 
  • eat leftovers within two days or freeze if you think this won’t be possible

Chilling food

Your fridge should be set between 0 and 5°C. Using a fridge thermometer is the best way to do this and we would recommend checking once a week. 

To make sure your fridge is running safely you can use the built-in dial or gauge inside the fridge to change the power setting. Check the manufacturer’s instructions on how to do this correctly.

You should always store any food with a 'use by' date, as well as cooked dishes, salads and dairy products, in your fridge.Follow  storage instructions on packaging, including the best before and use-by dates.

Keep chilled food out of the fridge for the shortest time possible during preparation (a maximum of four hours). And don’t leave the fridge door open for long periods of time, as your fridge then has to work harder to lower the temperature. 

Don't place hot or warm food in your fridge. Instead, cool cooked food at room temperature and place in the fridge within one to two hours. To cool food quickly, divide food into smaller portions in containers or freezer bags before putting in the fridge or freezer. 

Leftovers can be eaten cold if they have been cooked properly, cooled, and put in the fridge within two hours. Putting food in the fridge slows bacterial growth so it is safe to eat. Eat leftovers within 48 hours or freeze them if you think this won’t be possible. For more information see the 'Using your leftovers' section on our 'Cooking your food' page. 

Freezing Food

A freezer acts as a pause button - food in a freezer won't go bad and most bacteria cannot grow in it. It’s OK to freeze most foods as long as you check packet instructions to ensure that foods are suitable for freezing. 

Here's our top tips on freezing your food safely:

  • your freezer should be around -18°C
  • follow any freezing or defrosting instructions on the label
  • you can freeze food right up until midnight on the 'use by' date printed on the label
  • leftovers and homemade goods should be frozen as soon as possible
  • cool any warm dishes before putting them in your freezer
  • to cool food quickly, divide food into smaller portions in containers or freezer bags before putting in the freezer  

To stop the cold air in your freezer from drying out your food (known as freezer burn) you should: 

  • place food in an air-tight container
  • wrap it well in freezer bags or freezer wrap
  • label food you freeze so you don’t end up with Unidentified Frozen Objects (UFOs)
FSA Explains

Freezer burn

Freezer burn is when foods in the freezer are exposed to cold, dry air, which causes them to dehydrate and form ice crystals over time. This process affects the quality of the foods, rather than the safety.

Freezer burn can be avoided by carefully packaging foods in the freezer and checking foods aren’t kept for too long.

Meats are usually best eaten within 2-3 months. Baked goods, fruit and veg are best between 3-4 months.

Love Food Hate Waste have information on freezing leftovers, including recipe ideas.

Defrosting Food

You should defrost your food in the fridge so that it doesn't get too warm, see our Danger Zone info below for why this is important. It's also important to use food within 24 hours after it’s been fully defrosted – it will go bad in the same way as if it were fresh. 

When defrosting your food, make sure it has been fully defrosted and that the middle (and most dense bit of the food) is fully thawed. Partially defrosted food may not cook evenly and this means that harmful bacteria could survive the cooking process.

When defrosting food in the fridge use a container big enough to catch any drips. If this isn't possible, use a microwave on the defrost setting directly before cooking. Check the guidance on food packaging and allow enough time for your food to defrost properly.  

Other things to remember when defrosting your food:

  • always clean surfaces, chopping boards, utensils, plates and hands thoroughly with warm soapy water after they have touched raw or thawing meat to stop bacteria spreading around the kitchen
  • you can freeze food again once cooked, but you’ll only be able to reheat it once after that
  • freezing in individual portions will help you defrost only what you need 
  • we also have tips on defrosting a Christmas turkey and other large cuts of meat  

How to stock your fridge

It's especially important to store meat, fish and poultry safely to stop bacteria from spreading and to avoid food poisoning:

  • store raw meat, poultry and fish in their packaging or in clean sealed containers on the bottom shelf of the fridge, so they can't touch or drip onto other food
  • follow any storage instructions on the label and don't eat meat after its use-by date. 
  • when you have cooked meat and you're not going to eat it straight away, cool it and then put it in the fridge or freezer within 1-2 hours - remember to keep cooked meat separate from raw meat
  • store eggs away from other foods - it’s a good idea to use your fridge’s egg tray, if you have one, because this helps to keep eggs separate.
  • remember that some types of food might need to be kept in the fridge once you’ve opened them – follow any storage instructions on the label 

Also, you should not store food in an opened tin can. When a can has been opened and the food is exposed to the air, the tin from the can could transfer more quickly to the food inside. After opening a can of food, if you aren't going to use it all right away, empty the contents into a storage container, cover and refrigerate. 

FSA Explains

The Danger Zone

The cold temperatures of a domestic freezer (-18°C) delay chemical reactions within foods and put any bacteria that may be present on pause. 

The bacteria haven't been killed, and they may be revived as the food defrosts. Defrost food in the fridge to prevent it sitting in between 8 - 63°C, which is the Danger Zone.  Between these temperatures the bacteria may grow and make you ill. Generally, the colder the temperature, the slower bacteria will grow - but cold temperatures don't stop bacteria growing altogether (for example, listeria monocytogenes).

That’s why we advise that the safest way to defrost food is in the fridge overnight. By defrosting in the fridge, your food should never enter the ‘Danger Zone’.