Blackberry Jelly
["4 c. blackberry juice (about 3 qt. boxes berries)", "7 1/2 c. sugar", "1 bottle liquid pectin"]
["Sort and wash ripe berries; remove stems or caps.", "Crush berries and extract juice.", "Measure juice in kettle; stir in sugar.", "Place on high heat and stirring constantly, bring quickly to rolling boil that cannot be stirred down."]
["blackberry juice", "sugar"]