with liquid pectin
4 cups crushed blackberries (about 2 quart boxes blackberries)
7 cups sugar
1 pouch liquid pectin
Yield: About 8 or 9 half-pint jars
To prepare fruit:
Sort and wash fully ripe berries; remove any stems and caps. Crush berries and extract juice.
To make jam:
Measure crushed blackberries into a kettle. Add sugar and stir well. Place on high heat and, stirring constantly, bring quickly to a full boil with bubbles over the entire surface. Boil hard for 1 minute, stirring constantly. Remove from heat and stir in pectin. Skim.
Fill hot jam immediately into hot, sterile jars, leaving ¼ inch headspace. Wipe rims of jars with a dampened clean paper towel; adjust two-piece metal canning lids. Process in a Boiling Water Canner.
Recommended process time for Blackberry Preserves in a boiling water canner.
Process Time at Altitudes of : 0 - 1,000 ft - 5 min; 1,001 - 6,000 ft - 10 min; Above 6,000 ft - 15 min
Style of Pack - Hot
Jar Size - Half-pints or Pints.