Plum jam

You will need

1 kg pitted and halved plums
600g white sugar

Step one: Prepare fruit and sterilise jars

Start the night before: add the plums to a large stock pot or jam pan, toss with the sugar, replace the lid and leave to stand overnight so that the sugar draws out the fruit’s natural juices. The next day, when the jam is almost ready, sterilise the jam jars. Bring a large pot of water to the boil and submerge a clean jar and its lid. Boil for a few minutes and then set aside to dry.

Step two: Cook jam and skim scum

Place three saucers in the freezer. Slowly bring the fruit and sugar to the boil over a medium heat, stirring constantly, until the sugar has dissolved. Once the mixture has come to the boil, turn up the heat to high and boil for 15–20 minutes until the jam is ‘set’ (see test below). Stir occasionally to prevent the jam sticking to the bottom, and make sure it doesn’t burn. Once the jam is nearing completion, skim off the foamy scum that has risen to the surface.

Step three: Spoon into jars and seal

Spoon the jam into the sterilised jars, cover with a round of greaseproof paper dipped in vodka and seal the jar. The disc should fit the surface of the jam without folding up the sides.

How to test that the jam is ready

To test when the jam is set, remove one of the saucers from the freezer and drop a spoonful of jam onto it. Leave for a minute and then drag your finger through the jam. If the line remains, the jam is ready. Start testing the jam after 10 minutes of cooking.

Tips

•    Skimming scum ensures clear jam, but skimming towards the end of cooking time means less jam waste.

•    Use ripe fruit for flavour and a few under-ripe fruits for high pectin levels.

•    Preferably seal jam when hot; failing that, when fully cooled – but never when warm.

•    The jars should still be hot on being filled, so sterilise them in a pot alongside the jam. Alternatively, put jars through the dishwasher and use soon after the cycle is finished.