Bring the juice to the boil, boil it down to about half of its original volume and let it cool down. Chop the cranberries coarsely, mix with the sugar and juice.
Bring mixture to the boil while stirring, simmer for about 4 minutes. Peel ginger and chop finely. Clean the pepperoni, cut lengthwise, wash and remove the seeds. Cut the pod very finely. Cut the vanilla pod lengthwise and scrape out the pulp.
Cut the jam in half. Stir vanilla pulp into one half. Stir the ginger, pepper and salt into the second half. Immediately pour both flavours into clean glasses with twist-off lids. Close the glasses, turn them upside down for about 1/2 minute and label them immediately if possible.