Key Lime Mojito

2 1/2 cups light rum
3/4 cup fresh lime juice
3/4 cup fresh key lime juice
3/4 to 1 cup confectioners' sugar
3 3/4 cups club soda
10 large sprigs fresh mint, about 4 to 6 leaves each
Crushed ice
Key lime wedges, for garnish

In a large pitcher, combine rum, lime juices, and sugar. Stir until sugar has dissolved. Stir in club soda. Place mint springs in each of 10 glasses. Using the back of a spoon, crush mint leaves. Add crushed ice to glasses. Divide rum mixture between glasses. Garnish with lime wedges. Serve immediately.