Luke Whearty’s recipe, good for 1700ml: bake 50g of potato skins in the oven at 120 °C for half an hour. Place the skins in a plastic bag, pour in 1250ml of vodka, and add 500g of caramel. Squeeze the air out of the bag and heat in a water bath for 4 hours at 60 °C. Place in the freezer for a day, then filter the liquid into a separate container.