Peel and quarter the pears, remove the core and cut the pears into small pieces. Wash the cherries, drain them, remove the seeds and crush them as desired with a blender.
Mix pears, sour cherries, aniseed and jam sugar in a pot. Bring to the boil while stirring and let it boil fizzily for about 1 minute. Pour hot into the prepared glasses and close them immediately. Makes about 4 glasses.