English Raspberry Jam

Wash 7 to 8 190ml (8-ounce) jam jars with twist on lids in warm soapy water, rinse in clear water and put upside down in a low temperature oven 50-100ºC. This will sterilise and dry them. This can be done in a dishwasher as long as they come out dry.

If you have new lids, no further prep is necessary. If they have been pre-used, check that they are not damaged, then also wash and rinse them, leaving on a clean tea towel to dry.

Check the fruit and discard any squashy berries, then tip them into a heavy-bottomed large pan, or preserving jam pan.

Squeeze the juice from the lemon and add to the fruit. Set over a medium heat to cook the berries, stirring occasionally to prevent sticking. This will take no more than approximately 10 minutes.

Take from the heat and pour in the sugar. Stir until most of it is dissolved.

Set back on the heat and stir until you cannot feel the grittiness of the sugar. Increase the heat until the contents have come to a rapid boil and cook like this, without stirring, for around 4-6 minutes. (Do not go off and answer the phone at this point!)

Remove pan from the heat, place a small spoonful of the jam on a cold saucer to test for a set. Leave for a couple of minutes the push the jam with your finger—if the surface crinkles up, the jam is ready. If not, return to the boil and repeat the process.

Remove jars from the oven and use a jug or a ladle, or ideally a jam funnel, to fill the jars to the top. Screw on the lids immediately and leave the jam to cool and set. The contents of each jar will shrink a little, leaving a vacuum where no bugs can grow.

This jam will keep for at least a year without refrigeration, even after opening.

Delicious as a cake filling with cream, on toast or English scones.