Ingredients: to make 8 lb of jam
4 lb / 2Kg plums
4 lb / 2Kg sugar
¼ pint / 150ml water
Reduce the quantities in proportion if you do not have a large jam pan.
Put the fruit and water in a large jam pan and simmer until tender. Then allow to cool.
Squeeze the plums through the fingers into a bowl, retaining the stones with the fingers. Discard the stones.
Add the sugar to the plums and bring back to simmer, stirring slowly until all the sugar is dissolved.
Place 8 jam jars in a slow oven (gas mark 1/2 250 F 120 C)to heat up.
Boil rapidly until setting point is reached.
This is 220°F or 105°C measured with a sugar thermometer.
Test for setting point by removing a few drops of jam and letting cool. Push the cooled jam with a finger. If a skin crinkles on top of the cooled jam then setting point is reached.
Ladle the jam into the hot jars. A small jug makes this job easier.
Fill the jars right to the top and cover straight away with plastic covers. These can be cut from thin high density polythene freezer bags. Secure the covers with rubber bands and store in a cool cupboard.