Yield: About 8 or 9 half-pint jars
Procedure: Sterilize canning jars and prepare two-piece canning lids according to manufacturer's directions.
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.
|Table 1. Recommended process time for Blackberry Jam in a boiling water canner.|
|Process Time at Altitudes of|
|Style of Pack||Jar Size||0 - 1,000 ft||1,001 - 6,000 ft||Above 6,000 ft|
This document was adapted from "How to Make Jellies, Jams and Preserves at Home." Home and Garden Bulletin No. 56. Extension Service, United States Department of Agriculture. 1982 reprint. National Center for Home Food Preservation, June 2005.