Damson Jam

Directions

1. 1
   Place the damsons and water in a preserving pan; bring to the boil then simmer gently for at least 30 minutes until the fruit is really soft and the contents of the pan are well reduced (the exact time will depend on how gently you simmer the fruit - I like to do this step very slowly).
2. 2
   Remove the pan from the heat, add the sugar, stirring until dissolved, then add the knob of butter; bring to the boil then boil rapidly for 6 minutes.
3. 3
   Test for a set by placing a teaspoon of jam onto a very cold saucer, leaving to cool then pushing the jam with your finger to see if it wrinkles up: even if the wrinkle is only on the surface and faint, the jam really should be done (and don't forget it will set more in the jar); if the setting point hasn't been reached boil for one more minute (only) then test again using another saucer.
4. 4
   While the jam is still warm, pot it into sterilised jars.