For the medlar jam with rum pot fruits put medlars with water in a pot and boil for 10-15 minutes. Pass through a sieve.
This will yield about 1.9 kg of puree, add water or juice to make up to 2 kg. Mix with jelling sugar, lemon zest as well as lemon juice, bring to a boil and simmer for 4-5 minutes.
Stir in rum pot fruit and boil again briefly.
Pour into prepared glasses, drip a few drops of alcohol over them using a pipette, light and seal immediately.