Sort and wash berries; remove stems and caps. Crush enough berries, and press through a jelly bag or cheesecloth to extract 4 cups juice. Combine juice and sugar in a large saucepan, and stir well. Place over high heat; cook, stirring constantly, until mixture comes to a rapid boil. Boil hard 1 minute, stirring constantly. Add pectin, and bring to a full rolling boil; boil 1 minute, stirring constantly.
Remove from heat, and skim off foam with a metal spoon. Quickly pour hot jelly into hot sterilized jars, leaving 1/4 inch headspace; wipe jar rims. Cover at once with metal lids, and screw on bands. Process in boiling water bath 5 minutes. Yield 8 half pints.
