In a large kettle, bring the cherries and water to a boil; boil for 15 minutes. Add sugar and bring to a full rolling boil, stirring constantly. Boil for 4 minutes. Stir in pectin; return to a full rolling boil. Boil for 1 minute, stirring constantly. Remove from the heat; stir in extract. Skim off foam. Pour hot mixture into hot jars, leaving 1/4-in. headspace. Adjust caps. Process 15 minutes in a boiling-water bath.