4 c. blackberry juice
7 1/2 c. sugar
2 pouches liquid pectin

Measure juice into a kettle. Stir in sugar. Place on high heat and stirring constantly, bring quickly to a full rolling boil that cannot be stirred down. Add the pectin and heat again to a full rolling boil. Boil hard for 1 minute. Remove from heat; skim off foam quickly. Pour into sterilized hot jars and seal. Yield: 8 to 9 half pints.