Prepare the plums – Wash the plums, cut them in half, remove the pits, and roughly chop them.

Start cooking the fruit – Place the plums and water in a large saucepan and cook over medium heat until the fruit softens.

Mash the plums slightly – Use a spoon or potato masher to break down the fruit and release more juice.

Add sugar and lemon juice – Stir in the sugar and lemon juice until the sugar dissolves completely.

Bring to a rolling boil – Increase the heat and allow the mixture to boil rapidly for about 10–15 minutes.

Test the jam set – Drop a small spoonful onto a chilled plate. If it wrinkles when pushed, the jam is ready.

Skim foam if needed – Remove any foam from the surface with a spoon.

Fill sterilized jars – Carefully pour the hot jam into sterilized jars using a ladle.

Seal and cool – Close the jars tightly and allow them to cool completely.