Combine the cherries, sugar, and lemon juice in a large pot. Let the mixture sit for one to two hours. After it’s sat, heat the pot over low to medium heat and cook the cherry mixture for 45 to 60 minutes stirring often.
Once the jam is thickened, it’s ready. You can test this by spoon a small amount of the jam onto a small plate. If the jam runs down the plate when you tilt it, cook it a little longer until it’s thickened.