Freezing or deep freezing?
Freezing means storing food at a temperature between -18 degrees Celsius and -25 degrees Celsius, which can be done at home with a freezer. Deep freezing food is an industrial procedure which freezes food to a very low temperature (-35 degrees to -196 degrees!), very quickly. It’s impossible to do this with a normal home freezer. The main difference between the two is that you can keep deep frozen food for longer. It's not a good idea to freeze dishes or your garden fruit for months on end.
You can't freeze everything
Although many types of food and dishes can be frozen, there are a few exceptions that you should know about: namely food that is sensitive to bacteria. The freezing process does not kill bacteria; it just stops them from multiplying. During defrosting, they start contaminating again.
Take care with the packaging
Keep the original packaging, as this is useful as an indicator of the use-by date and cooking/freezing/defrosting instructions.
For unpackaged food (home made dishes, garden veg, fruit from the market etc.):
- only freeze cold food, otherwise it will frost over
- stick a label on each product indicating the contents and the date you froze it
Make sure the wrapping or container is perfectly airtight. The packaging must be air and water tight to prevent loss of humidity.
- plastic freezer bags once only (flatten to remove the air)
- thick aluminium foil (to prevent tearing) and cling film
- aluminium boxes (reusable as long as you wash them well)
- plastic boxes (don’t fill up to the edge: leave at least 1cm of space under the cover, as when the food starts to freeze it will increase in volume)
- set your freezer to -18 degrees.
- never refreeze a product that has already been frozen (except if the product was completely defrosted then well cooked, in which case it can be refrozen).
- never cut the cold chain: when you buy frozen food, place it in an ice box or an isothermic bag and freeze it as soon as you get home. If you are going to be away for a while or if it's very hot, avoid buying frozen food.
- Wash your fruit and veg before freezing them.
How long can you keep frozen food for?
Deep frozen food:
Meat and fish
Fruit and vegetables
Home frozen food:
Pork, lamb and veal
Beef, poultry and offal
Fruit and vegetables
Freezing does not kill bacteria, so defrost your products in the fridge or use the defrost function on your microwave. It's best to cook food from frozen either in the microwave, pan or wok, and this is possible for many foods: fish, vegetables and fruit steamed of in parcels, and pre-prepared meals. Never ever drink the juice produced by defrosting.