Split the vanilla pod lengthways and scrape out the seeds.
Pour the blackcurrant cordial into a saucepan and add the sugar, orange slices, cinnamon sticks, cloves, cardamom pods, peppercorns, star anise, vanilla seeds and the empty pod.
Set the hob to medium and let it simmer for 20-30 minutes. It should not boil – just simmer until the sugar has dissolved and the spices have released their aroma.
Scald a preserving jar or similar with boiling water, then pour in the port and rum.
Then pour in the contents of the pan, spices and all, put the lid on and refrigerate for 2 days.
After 2 days, remove the orange slices and the extract is ready to use. It can happily infuse for longer, though, so do leave it in the fridge with the spices still in – they add plenty of flavour.
Strain out the spices when you are ready to use the extract. I pour the amount I need through a fine-mesh sieve and leave the spices in the rest of the extract in the fridge.I mix 150 ml extract with 1 bottle of red wine – but experiment. You may prefer it milder or stronger.