Start by bringing 1 quart of water to a rolling boil in a medium saucepan. Once boiling, remove from heat and stir in 3/4 cup of granulated sugar until dissolved. Allow to cool.

As the syrup cools, cut the lemons in half and squeeze the juice from half of a lemon into each of four glasses.

Fill each glass generously with ice, about three-quarters full.

Pour the cooled simple syrup over the ice and lemon juice until each glass is filled.

Cover each glass and shake vigorously for about 15-20 seconds to mix all flavors.

Serve immediately, adding fresh mint if desired.