Swiss cherry conserve

Method

1. Wash the cherries and dry them well on a clean tea towel. Working over a bowl so you collect the juices, remove their stones. Using a cherry pitter is by far the quickest way, but you can cut the cherries open and remove the stones with the tip of a small sharp knife.
2. Put the pitted cherries and the jam sugar in a large mixing bowl and stir together well. Set aside for at least 3 hours, stirring now and then, to encourage the juices and sugar to produce a syrup. Put the granulated sugar in a heatproof mixing bowl.
3. Heat the oven to 150°C/130°C fan/gas 2. Put 3-4 small saucers in the freezer and wash the jars. Put them in the oven with the bowlful of sugar and leave for 15 minutes for the jars to sterilise and the sugar to warm.
4. Transfer the cherries and syrup to a large stainless steel pan, add the lemon juice and bring to a gentle simmer. Cook for 5-7 minutes until the fruit is just tender. Add the oven-warmed granulated sugar and stir gently over a low heat until the sugar has completely dissolved (take care not to overcook the fruit – keep the cherries as intact as possible).
5. When the sugar has dissolved, increase the heat and bring to a steady boil. Boil without stirring for 6-8 minutes, then check for setting point. To do this, take the pan off the heat, spoon a little jammy syrup onto a chilled saucer, then return it to the freezer for 4 minutes. Push your finger through the jam – if it wrinkles up into a peak with no liquid running onto the saucer, it’s ready. If it doesn’t, return the pan to the heat and boil for another 2 minutes more, then retest.
6. Remove the jam from the heat and leave to cool slightly until, when you stir it, the scum disappears and the cherries stay suspended in the syrup (about 15-20 minutes).
7. Pour the jam into hot sterilised jars (use a funnel or jug – and take care), filling them to within 3-6mm of the rim. Immediately cover the surface of the jam with waxed discs, then lids (or cellophane discs with a rubber band) while still hot. Label and store in a cool dark place. The jam will keep for at least a year.