The airtight sealing of foods in containers in association with heat and/or chemical treatments is a very effective method of preserving food. Foods such as fruit, vegetables, meat, fish, or a combination of these foods (e.g. meat and vegetable condensed soup, sauces and fruit salad) can be stored safely in airtight sealed containers.
How are canned foods made commercially?
Canned foods are washed, prepared and filled into metal containers along with a canning fluid (e.g. water, salted water or fruit juice). The food is heat treated to produce a commercially sterile shelf-stable product with an air-tight (vacuum) seal. Heat treatment kills organisms that may spoil the food or cause food-borne illnesses. Contents remain commercially sterile until the container is opened and the vacuum seal is broken.
How long can I keep canned foods?
While canned foods do not change suddenly, slow changes do occur in the container and food quality may change over time. The storage life depends on a number of factors, including conditions of storage and the nature of the food. As a general rule, the best shelf life will be obtained when canned foods are kept in a cool, dry place. For best results, it is recommended that your supplies of canned food are refreshed periodically.
Canned foods may have a use-by or a best-before date.
Where a food needs to be consumed within a certain time for safety reasons, a use-by date must be provided. Do not purchase or consume any food past its use-by date.
A best-before date applies to the quality of the product. It is safe to purchase and consume the product after its best-before date, however the food may not be at its peak quality. Read more about use-by and best-before dates
Canned foods that have a shelf-life of more than two years do not need a best before date. As long as the container remains intact, canned foods have a long shelf life even at room temperature. The sealed containers prevent contamination of food by organisms that can spoil the contents or cause illness to people.
How do I store canned foods at home?
Check the label of the product for any storage instructions. If storage conditions are required for health and safety reasons then the label must state these conditions. Generally, canned foods are designed to be stored at room temperature.
If instructions are not provided on the label, then store in a cool dry place. Handle canned food carefully to avoid denting or other damage which could affect the can's seal. Rotate food in your pantry by using older stock first.
How do I select canned foods?
Always check food containers for:
- swelling and/or leakage
- rust and scratches
- broken tamper-evident seals
- dents or damage
- damaged seams (joins).
Do not purchase the food if you see any of these problems.
Inspect the container as outlined in 'How do I select canned foods?' before use. If there are signs of damage, do not use or taste the food.
Wipe or wash the top of the container before opening. Always use a sharp clean can opener and wash the opener after every use.
Practice good hygiene as if you were handling fresh food. Keep all food preparation surfaces and implements clean, and wash hands in warm soapy water before preparing food.
If the contents have an unusual odour or colour, or if you notice that the inside of a metal container (or lid) is rusted, throw out the contents. Do not use or taste the food.
Canned foods are often highly perishable and can spoil quickly once they are opened. Opened canned food should be treated in the same manner as fresh food, and should not be stored any longer than its uncanned version. If not used immediately, the contents of the opened container should be emptied into a clean plastic or glass container, covered and stored in a refrigerator.
What should I do if I suspect problems with these foods?
You should report any doubtful product to the manufacturer. If you have any concerns about a particular food, you could alert the food enforcement agency in your state, territory or region.
What about foods in containers other than cans?
Other packaging options that manufacturers use include:
- glass jars
- plastic tubs
- flexible pouches
- ultra-high temperature (UHT) cartons.
Foods in these packages are often processed in a similar way to canned foods, and like canned foods they will spoil quickly after opening. Check for date marks on these products in the same way as for canned foods.
Food should be discarded without tasting if it shows signs of damaged packaging or sealing.
Glass jars and plastic tubs are almost always vacuum sealed. Any product where the lid is not clearly sealed and typically 'sucked down', should not be used. Any flexible pouch or carton that has leaked or is swollen or under pressure should not be opened.