Use by and best before do not mean the same thing

A use by date sits on food that can make you ill once it turns: meat, fish, soft cheese, ready meals, bagged salad. The bacteria that matter here do not announce themselves. Food can look right and smell right and still not be safe, which is why the date is the rule, not your nose.

Do not eat, cook or freeze anything after its use by date has passed. Up to and including the date, all three are fine.

A best before date sits on food that keeps: tins, pasta, biscuits, frozen food, most bread. After the date it is still safe to eat. The maker is only saying it may not taste or feel its best. Here your senses are exactly the right tool: look at it, smell it, try a little.

Shops are allowed to sell food past its best before date, and some sell it cheaper on purpose. Nobody is allowed to sell food past its use by date. That difference tells you how seriously to take each one.

Both dates describe an unopened packet, stored the way the label says. Open a jar and a different instruction takes over, usually printed next to the date: use within so many days of opening. From that moment the opened rule is the one that counts, even if the printed date is weeks away.

You can freeze food at any point up to and including its use by date, and the little snowflake day counts. Freezing pauses the date rather than erasing it: defrost the food properly and use it within a day, or cook it, after which it can be frozen again. If tonight is the date and dinner is already planned, the freezer is the honest way out.

Fruit and vegetables sold loose carry no printed date, so anything anyone tells you about them is an estimate. Estimates are useful, but they are guesses, and a guess should never outrank a printed date. Treat an estimated date as a reminder to look at the thing, not as a verdict.