Pit and stem 1 pound of sour cherries.
Add cherries to a pot with 2 cups of water and 1 pound of sugar. Turn heat to low and stir until sugar is dissolved.
Bring the mixture to a boil, then reduce it to a simmer. Simmer for 20 minutes until cherries are soft.
Take cherries out of the syrup, and boil the syrup until it is thick enough to stick to the back of your spoon. Turn the heat off, then add cherries back in.
Let the mixture cool and store it in a sealed container.