step 1
Put the plums and wine into a preserving pan, and place the spices and zest into the pan. Cook gently until the plum skins are soft.
step 2
Add the sugar, stirring until dissolved. Bring to the boil and boil rapidly for 10 minutes or until the setting point has reached.
step 3
Add a knob of butter and stir in.
step 4
Pot into cool, sterilised jars, seal and label.