Canning method
Sterilize canning jars and prepare two-piece canning lids according to manufacturer s directions. To prepare juice. Sort and wash fully ripe berries; remove any stems or caps. Crush berries and extract juice. To make jelly. 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 pectin and heat again to a full rolling boil. Boil hard for 1 minute. Remove from heat; skim off foam quickly.
Pour hot jelly immediately into hot, sterile jars, leaving 1/4 inch headspace. Wipe rims of jars with a dampened clean paper towel; adjust two-piece metal canning lids. Process in a Boiling Water Canner .
Processing: Process Hot, Half-pints or Pints, boiling-water canner, 0 - 1,000 ft - 5 minutes.
Altitude-adjusted processing table: Table 1. Recommended process time for Blackberry Jelly in a boiling water canner. / Process Time at Elevations of / Style of Pack - Jar Size - 0 - 1,000 ft - 1,001 - 6,000 ft - Above 6,000 ft / Hot - Half-pints / / or Pints - 5 min - 10 - 15