Wash the sour cherries, remove the stems and pits, sprinkle with the sugar and leave to sit for 12-16 hours. Then boil them on medium heat, remove the foam using a wooden spoon.
Near the end of the boiling, add the glucose and citric acid and boil to the necessary density. After removing the jam from the heat, add the vanilla - can be substituted with geranium.
Put the finished jam into jars, seal with caps and store in a dry and dark place.