5 1/2 cups seedless blackberry pulp (about 6 [18-oz.] packages blackberries, crushed and pressed through a fine-mesh sieve twice)
1 (1.75-oz.) box powdered pectin
1/2 teaspoon unsalted butter (optional)
7 cups granulated sugar
1/4 cup Chambord
How to Make It
In an 8-qt. stainless steel stockpot, combine the blackberry pulp and pectin. Add the butter, if using. Bring the mixture to a full rolling boil over medium-high heat, stirring constantly.
Add the sugar, and stir until completely dissolved. Return the mixture to a full rolling boil, stirring constantly. Boil for 1 minute, stirring constantly.
Remove the pot from the heat, and skim off any foam. Add the Chambord, and stir until well blended. Let the jam rest for a few minutes, stirring occasionally.
Ladle the jam into hot jars, leaving 1/4-inch headspace. Remove any air bubbles by gently tapping the jars. Wipe the jar rims and threads with a clean, damp paper towel. Cap the jars with hot lids, and screw on the bands.
Process 4-oz., 8-oz., and pint jars in a water bath canner for 10 minutes. Remove from the water bath canner, and let cool for 12 to 24 hours. Check the seals, and remove the screw bands. Store jars in a cool, dry, dark place for up to 1 year.
Serving Suggestion: Enjoy this jewel-toned jam on toasted bread, muffins, and scones or as a topping for vanilla ice cream. It also makes a wonderful filling for individual fruit tarts and shaped cookies.