From My Carolina Kitchen
1 lb fresh or frozen and thawed blackberries (4 cups)
¾ cup sugar
2 tablespoons powdered fruit pectin. I used Sure Jell. (Do not substitute liquid or low-sugar pectin.)
1 tablespoon fresh lemon juice
Mash blackberries with a potato masher or a fork in a large bowl. Stir together the berries, sugar, pectin, and lemon juice in a 12-inch nonstick skillet, then boil, stirring occasionally, until slightly thickened, about 7 minutes. Transfer jam to a large shallow bowl, cover jam surface with wax paper, and chill until softly set, at least 30 minutes. Jam will set further if chilled longer. Jam keeps, chilled in an airtight container, for 2 weeks.
Gourmet Comfort – makes about 1 ½ cups