Peel the apples and floury raw potatoes. Then put both in a saucepan one after the other over a grater. Drizzle with the juice of a lime so that everything doesn't turn brown straight away. Then cut open a vanilla pod, scrape out the pulp and put both in the pot.
Now the whole thing is infused with the naturally cloudy apple juice. Bring to the boil while stirring and then switch down, simmer for about 5 minutes. Then you add the preserving sugar & the rum. Now mix everything together and let it simmer while stirring constantly.
When the whole thing is jelly, remove the vanilla pod pieces and then put them in jars that have been rinsed with hot water, seal.