How to make
Wash the cherries well and remove their pits. Pour the sugar over them and leave to sit for about 12 hours as is.
Then put them to boil on low heat, occasionally removing the foam that forms.
You'll know that the jam is ready when you pour a drop of it on a plate and it doesn't run.
Before it's fully ready, pour the citric acid into it.
Wait for it to cool and distribute it into dry jars. Then sterilize for 5-10 min.