In a large saucepan, combine all ingredients. Stir and cover. Cook over medium-low heat for 20 minutes. Stir occasionally.
Remove the lid, stir the mixture and increase the heat to medium or medium-high. Cook for 35-45 minutes (the cherries should maintain a steady boil). Stir frequently to prevent burning. When the mixture is reduced, thickened and coats the back of a spoon it is finished cooking.
Remove from the heat and cool to room temperature. Store in the fridge.