Wash the early plums, pat dry with kitchen paper and then remove the seeds. Take a medium saucepan and add it there. Then puree with a magic wand. Then add all ingredients except for the preserving sugar 2:
Stir the whole thing well, close it with a lid and let it steep for 4 hours. Then the preserving sugar comes in and the whole thing is boiled up. Then let the mixture simmer for about 5 minutes. Then remove the cinnamon stick and fill it into one or two glasses, depending on the size.