Conduct a forensic examination of the packets, tins, jars and other containers in your pantry and fridge and you don’t need to work for CSI to see how long most of them have been there.

In most cases the date is clearly marked – those spices bought for a one-off curry around 2005 or that block of feta that has hidden at the back of the fridge for nine months.

But what does that date actually mean and what is the difference between a “use by” and a “best before”.

This advice, based on information mostly from Food Standards Australia, should help you waste less food as well as keep your family safe.

The meaning of Use by

A Use-by date normally will be marked on foods that shouldn’t be consumed after a particular date for health or safety reasons. In other words, eating them has the potential to cause illness or worse through food poisoning.

Use-by dates are particularly important on cooked, ready-to-eat meals that are chilled rather than frozen. Milk also has a use-by date – though you will normally smell when it is past its best before you drink it.

Shops are not allowed to sell food that is past its use-by date.

What does Best before mean?

A best-before date is used for shelf-stable foods such as biscuits and confectionery, frozen foods and most raw food (meat, chicken, fish) that will be cooked before being eaten.

These foods can still be eaten safely after the date marked on them, but they may no longer be at their best in flavour or nutritional benefit.

Shops are allowed to sell food past a best-before date.

Food with a shelf-life of more than two years does not have to carry any date stamp.

Baked on, Baked for – bread rules

Bread is an exception to the rule and can carry a “baked on” or “baked for” date.

Can I still eat food past its use by date?

Manufacturers tend to be cautious in determining a best-before date and a commonsense approach from the consumer can prevent food being wasted. Keeping food in a cool, dark cupboard will improve its shelf life.

If food is obviously mouldy, spoilt, discoloured or infested with insects, then it should be thrown away. But if its packaging is intact and the date not too ancient, it is probably fine to consume.

Older food may be best used in a way that doesn’t rely on it being at its peak – save a can of chick peas for a curry, say, rather than in a salad.

Use by dates for cans

Cans of food are mostly sterilised by heating during production and can have a shelf life of up to four years.

Do not consume the contents of cans that are swollen, leaky, severely dented or showing any sign of rust.

Freezing food

Food kept below -18C should stay in near-peak condition for several months. It’s worth checking the temperature of your freezer, because higher temperatures will reduce this time. Buy frozen food with no obvious ice crystals, damaged packaging or iced-together lumps. Select frozen goods last when shopping and transport in an insulated container.

Top food guides
A guide to supermarket dates
The ultimate storage guide for Christmas
How to freeze food
The ultimate guide to free-range eggs
How to use up Christmas leftovers

See also
How to spring clean your diet
Ways to reduce food waste
How to use all those leftovers
Why leftovers are the best – BEST RECIPES