Jars can be stored in a cool, dark place for up to a year, but once opened keep in the fridge.
Makes about 2.5kg (5 ½ lb)
1.5kg (3lb 3oz) firm plums
1.5kg (3lb 3oz) granulated or caster sugar
Most varieties of plum make delicious jam.
1. Halve the plums and remove the stones. (If the fruit is too hard to remove them easily, you can cook with the stones in and use a slotted spoon to scoop them out when the jam is boiling.)
2. Put the fruit in a large heavy-based or preserving pan. The pan should not be more than half full to ensure sufficient space for rapid boiling. Add 600ml (1 pint) water and bring to the boil. Reduce the heat and simmer gently for about 30 minutes, or until soft. The exact time will depend on the ripeness of the fruit.
3. Add the sugar and stir until it has completely dissolved, then bring back to the boil. Boil steadily and rapidly for 15–20 minutes, or until setting point is reached.
4. Remove from the heat and skim any froth from the surface of the jam. Let the jam stand for about 5 minutes, then ladle it into warmed, sterilized jars, cover, and seal.
Recipe taken from ‘The Cook’s Book of Ingredients’, published by Dorling Kindersley (£30)