4 c. blackberry juice (takes about 3 qt. boxes berries)
7 1/2 c. sugar
1 bottle liquid pectin

To prepare juice: Sort and wash fully ripe berries. Remove any stems or caps. Crush the berries and extract juice.

To make jelly: Measure juice into a kettle. Stir in the sugar. Place on high heat and stir constantly. Bring quickly to a full rolling boil that cannot be stirred down. Add pectin and heat again to full rolling boil. Boil one minutes. Remove from heat; skim off foam quickly. Pour jelly into sterilized HOT containers and seal. Yields 8 to 9 (8 ounce) glasses.