250 brown sugar
place the plums in a pan with 100 ml water and bring to a simmer, then cook gently for 10 minuters until the plums are soft but still intact.
Add the sugar to the fruit and stir over a low heat untill all the sugar has dissolved, cook for 30 minutes
Sometimes this can take a 30 minutes and on other occasion up to 40-50 minutes, depending on how much water the jam contains.
Pour the jam into hot, sterilized jars and seal.