Tart Cherry Jelly

Place unpitted fresh cherries or frozen cherries in a 6- to 8-quart heavy pot. Add the water. Bring to simmering (do not boil). Simmer, uncovered, about 15 minutes or until cherries are soft and the skins begin to split. Using a potato masher, carefully crush cherries. Remove from heat.

Place a fine-mesh sieve over a large bowl. Ladle cherries into sieve. Using the back of a large spoon, press cherries to release juice; discard pits and pulp. Line a colander with a double layer of 100-percent-cotton cheesecloth; place over a large bowl. Strain juice through cheesecloth; do not squeeze cheesecloth or jelly may be cloudy. Measure 3 1/2 cups juice. Discard pulp in cheesecloth.

In the same pot stir together the 3 1/2 cups cherry juice and the pectin. Bring to a full rolling boil, stirring constantly. Add sugar. Return to a full rolling boil, stirring constantly. Boil hard 1 minute, stirring constantly. Remove from heat. Quickly skim off foam with a metal spoon.

Ladle hot jelly into hot, sterilized half-pint canning jars, leaving a 1/4-inch headspace. Wipe rims; adjust lids and screw bands.

Process filled jars in a boiling-water canner 5 minutes (start timing when water returns to boiling). Remove jars from canner; cool on wire racks.