Clean and wash the cherries. Take the pits out over an enamel or porcelain container, to collect the juice.
Pass them through a sieve (I put them in a juicer). Measure out the resulting juice, add 2 cups (500 g) sugar for every 1 cup juice.
Boil the mixture in an enamel container, while stirring with a wooden spoon. Aromatize with geranium leaves.
Once the syrup begins to thicken, add the citric acid, stir well, remove the container from the stove and scoop out the foam.
When cooled a bit, distribute out into dark bottles with metal caps.
Close well, store in a dark and cool area.
Note: If you don't have a cool cellar, sterilize the syrup for 5 min. and leave 1 bottle in the fridge for quick consumption.