Wash the jars thoroughly, then dry them in a warm oven - this means they will be less likely to crack from the heat of the jam, and more likely to seal well.

When filling with a cold product, warm the lids at no more than 55 degrees C. This will soften the PVC compound and takes pressure off the lid, which is less likely to bend when fitting.

To test if your jam is set, take your saucepan off the heat. Then place a dollop of the hot jam onto a chilled saucer. Return the saucer to the fridge for a minute and if the jam has reached setting point, the dollop shouldn't be runny.

Many home made berry jams and jellies will not set as firmly as commercial products

To stop any fruit rising to the surface when you bottle the jam, leave the jam in the saucepan for 10-20 minutes before you spoon it into the jars

Never re-use lids, these are cheap and easy to buy. The compound inside which seals against the jar is not able to be sterilised, unlike the jars, which can be used over and over again.

Jars are measured by fluid capacity. Any attempt to transfer this into weight eg. 1lb jam jars, can be incorrect if the product is bulky. For example 1lb of jam will not fit into a 1lb honey jar.

All honey crystallises with time. To return it to its liquid state simply remove the lid and warm gently in a pan of water or store in your airing cupboard for a few days.