Tip the jam into a wide-necked jug with a good ... giving a wide window of availability. To prevent the plum skins toughening, do make sure the plums are lightly softened before adding the sugar.
The flavour of plums becomes more intense as they bubble away in the pot for this dessert plum jelly. (Once you have drained all the juice for the jelly, store the plums in the fridge to eat with ...