Remove the stems from the washed currants. Lightly mash the currants, then add the washed and pitted cherries. Mix all fruits with the preserving sugar and leave to steep in the refrigerator for approx. 3 - 4 hours.
Since the jam should be chunky, it is not necessary to puree the fruit. Bring the fruits to the boil while stirring, let simmer for 4 minutes.
Stir in the Campari, bring to the boil briefly and pour the hot jam into clean twist-off glasses and immediately close tightly.