Simmer prepared cherries with water 8 to 10 minutes until soft enough to mash.
Mash, stir in sugar, bring to a full boil that cannot be stirred down, and boil 1 minute.
Remove from heat, stir in the full pouch of liquid pectin, skim foam, and fill hot jars with 1/2-inch headspace.
Process half-pints or pints for 15 minutes at 0–1,000 ft, 20 minutes at 1,001–6,000 ft, or 25 minutes above 6,000 ft.