* use about two-thirds fully ripe grapes and about a third firm yet ripe grapes Wash and stem grapes. Crush grapes in a 6 or 8-quart Dutch oven or kettle. Add the water. Bring to boiling over high heat; reduce heat. Cover and simmer about 10 minutes or till grapes are very soft. Using a jelly bag or a colander lined with several thicknesses of 100% cotton cheesecloth, strain the mixture. (This will take about 4 1/2 hours.) Chill the juice for 12 to 14 hours. Strain again through jelly bag or 100% cotton cheesecloth. Place juice in Dutch oven or kettle. Add sugar; stir to dissolve. Bring to a full rolling boil. Boil hard, uncovered, till syrup sheets off a metal spoon or reaches 220 degrees F on a jelly thermometer. This will take about 20 minutes. Remove from heat. Quickly skim off foam with a metal spoon. Immediately ladle jelly into hot, sterilized half-pint canning jars, leaving 1/4" headspace. Wipe jar rims and adjust lids. Process jars in a boiling water canner for 5 minutes (start timing when water begins to boil). Remove jars from canner; cool on racks. cook's notes The grapes in this jelly should be at two stages of ripeness. Less ripe grapes contribute more pectin than the fully ripe grapes, helping the jelly to set. Fully ripe grapes lend a richer flavor.