Preparation Stir together all ingredients in a pitcher until sugar is dissolved. Serve over ice. Cooks' note:To make blackberry syrup, heat 1/4 cup blackberry jam with 1 tablespoon water in a small saucepan over moderately low heat, stirring, until jam is dissolved. Pour mixture through a fine-mesh sieve into a small bowl, pressing on and then discarding solids. Syrup keeps, covered and chilled, 1 week.
Preparation Stir together all ingredients in a pitcher until sugar is dissolved. Serve over ice. Cooks' note:To make blackberry syrup, heat 1/4 cup blackberry jam with 1 tablespoon water in a small saucepan over moderately low heat, stirring, until jam is dissolved. Pour mixture through a fine-mesh sieve into a small bowl, pressing on and then discarding solids. Syrup keeps, covered and chilled, 1 week.