Tie the spices with long string in a gauze cloth. Sort the jostaberries and wash them if necessary.
Place in a saucepan and lightly mash, add the jelling sugar and spice bag. The spice bag can be tied to a saucepan handle to make it easier to remove later.
Mix everything well, cover and let stand for a few hours. Then cook the mixture according to the instructions on the jelly sugar package, remove the spices and fill the jam into sterilized jars.