Wash and stone the plums. Put all ingredients in a saucepan and simmer for 5 minutes. Remove the cinnamon stick. Pour the plums with the red wine stock into a clean container and close tightly. Let it steep for 2-3 weeks.
Drain the vinegar through a sieve lined with a cloth (linen, if you have it). Squeeze the plums well. Pour the finished plum vinegar into a bottle and close it. Makes approx. 3/4 L.
Plum vinegar goes well with raw vegetables, game dishes, salads and for seasoning fruit salads.