Makes about 2½kg/51b
1 ½kg/ 3 lb. plums
450ml/ 3/4pt water
1 1/2kg/ 3lb. sugar
15g./ ½oz. butter or margarine
1 Wash the plums in a colander. Put them into a pan with the water. Simmer gently until the plums are cooked, about 15 minutes.
2 Add the sugar and stir until it is dissolved. Boil briskly until setting point is reached.
3 Take from the heat and remove all the stones with a perforated spoon. Stir in the butter to remove the scum.
4 Pour into clean, warm jars, cover, and label.