1. In large, metal (non-aluminum) saucepan, add blackberries, lemon juice and pectin.
2. Bring to a full boil, stirring constantly.
3. Stir in sugar and return to a full rolling boil.
4. Continue to boil, constantly stirring, for 2 minutes.
5. Remove from heat and skim off any foam that forms on top as mixture cools.
6. Pour into storage jars, leaving 1/4 inch headspace above lid. Attach lids according to manufacturers directions.
7. Process in a simmering water bath for 10 minutes.
Allow to cool and store in pantry.