The shelf life of food is one of those things, because we know that it is often edible well beyond its printed best-before date, especially when it comes to industrially produced products that have not yet been opened.


You should try an expired jar of instant coffee first before throwing it away, as the flavour and consistency of the powder will probably be exactly the same for quite a long time after the expiry date as with non-expired products.

But you can also test the shelf life of fresh products yourself, some of which are listed here:

Eggs

Test the shelf life of eggs: put a raw egg in a container of water, if it sinks, it is still OK, if it floats to the top, it is bad and should be disposed of unopened.

Yoghurt

Yoghurt, fresh cream or similar products in tubs are easy to check, because if the metal lid is very strongly curved upwards, the product is no longer edible, the gases produced in it lift the lid.

Milk

Milk not only smells sour when it is bad, but also curdles in other liquids, i.e. it appears flaky instead of mixing.

Pickles

Pickled cucumbers, olives, chilli, etc. have a very long shelf life due to the oil and vinegar content, especially in the fridge, which is why you can usually use the contents beyond the date printed on the jar after opening. However, you should dispose of these items if the water in the jar has become very cloudy and a greasy film is floating on top.

However, to ensure a long shelf life and prevent mould, the contents must not be removed with fingers or used cutlery and the jar must always be carefully sealed airtight immediately after use.

Marmalade

Jam will keep for years unopened in the jar, but it should be stored in a cool, dark place so that the colour does not change; heat can also cause it to ferment in the jar.

Jam is always bad if mould has formed on it, which is why it must always be sealed airtight after use.