Prepare the rhubarb – Wash the rhubarb, trim the ends, and cut it into small pieces.

Cook the rhubarb first – Place the chopped rhubarb and water in a saucepan and cook over medium heat until the fruit softens.

Mash lightly – Use a spoon or potato masher to break down the softened rhubarb slightly.

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 boil the mixture rapidly for about 10–15 minutes.

Test the jam set – Place a spoonful on a chilled plate. If the surface wrinkles when pushed, the jam is ready.

Remove foam – Skim off any foam from the surface for a smoother jam.

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.