1. Slice plums into quarters or smaller and remove the stone.
2. Add plums and water in saucepan and cook for five minutes until the plums have softened.
3. Add sugar and lemon juice to the saucepan set over medium-low heat and simmer until the sugar dissolves.
4. Once sugar has dissolved, increase heat to medium and boil for ten minutes until visibly reduced and thickened.
5. Dollop a spoonful of jam onto a plate (from the freezer) and run a pass through it with your finger. If the jam wrinkles and stays separated- you are ready!!
6. Ladle into a sterilised jars and store.