Gently wash the strawberries – if necessary – drain well and cut into small pieces (or chop with a blender).
Wash and peel the rhubarb stalks and cut them into 1 cm pieces.
Place the chopped fruit in a large saucepan with lemon juice and half of the preserving sugar, mix, and let stand covered for at least 3 hours or preferably overnight.
Bring to a boil while stirring, stir in remaining jam sugar and boil for 5-10 minutes until bubbly.
After about 5 minutes, do the first gelatinization test.
If the consistency of the rhubarb jam is right, immediately pour into hot rinsed jars, drizzle a few drops of alcohol on top using a pipette, light and seal immediately.
Skim off any rising foam before filling.
Preparation Tip:
To refine the jam, stir 120 ml of eggnog into the jam before filling the jars, but then reduce the amount of fruit by 120 g.