Push a stick into each apple. Sprinkle 4 tablespoons sugar evenly onto a baking sheet or flat tray.
Place sugar, water, food colouring and vinegar into a stainless steel pot with a thick bottom and bring to a rapid boil. Rapidly boil until the sugar thermometer reads 150 C.
Remove the pot from the heat immediately and dip the apples one after the other into the liquid until they are completely covered in the syrup. Place them upside down onto the prepared baking sheet to cool and drain.