Here is what you'll need:
1 1/4 cups plus 1 tsp fresh lemon juice
3/4 plus 2Tbs simple syrup*
1 pint fresh blackberries--juiced (about 1/2 cup)
4 1/2 cups ice cubes
Juice your lemons--or make your nephew do it like I did!
Combine 1 1/4 cups of lemon juice with 3/4 cup of simple syrup and set aside.
Heat blackberries over medium heat until very juicy, stirring periodically--10 minutes. Press through sieve. Should produce about 1/2 cup of juice.
Stir together blackberry juice, 1 tsp. of lemon juice and 2 Tbs of simple syrup. Set aside.
Put ice cubes in blender with lemon juice mixture. Crush ice until smooth.
Pour 1 - 2 Tbs of blackberry juice in each of 4 glasses.
Pour frozen lemonade into glasses, dividing evenly. Garnish with mint sprig and blackberries (optional). Serves 4.
*simple syrup is one cup water to one cup sugar--heated on stove top until sugar is dissolved.