Bring the blackberry juice with red wine, preserving sugar, citric acid, vanilla pulp and vanilla pod to the boil and cook for 3 or 4 minutes, depending on the instructions. If necessary, skim, remove the pod and pour the jelly into glasses that have been rinsed with hot water. Let stand upside down for 5 minutes, then turn over again.
I cooked that once when the juice wasn`t enough and I took red wine to fill up. Since then, I`ve only been using this recipe because it tastes delicious.