Please read About Making Jelly and How to Process.
Wash and drain, then thoroughly crush in a large heavy saucepan:
Cover and bring to a boil, then reduce the heat to low and simmer for 10 minutes, mashing frequently. Extract the juice. While the juice drains, prepare a water-bath canner, gather all your canning equipment, put a couple of saucers in the freezer, and have ready 3 sterilized hot half-pint jars.
Measure the strained juice, transfer to a large saucepan, and add:
Boil rapidly, stirring constantly, until the mixture reaches the jelling point. Remove the jelly from the heat and skim off any foam. Pour into the prepared jars, leaving ¼ inch headspace. Wipe the rims. Place lids on jars and screw on rings until fingertip-tight. Process for 5 minutes. Let cool completely and store as directed.