- 1 1/2 cups white sugar
- 8 lemons, halved
- 8 limes, halved
- 4 cups water, divided, or to taste
- 1 lemon, sliced
- 1 lime, sliced
- ice cubes
- Preheat grill for medium heat and lightly oil the grate.
- Pour sugar into a saucepan; press halved lemons and limes cut-side down into the sugar.
- Set the saucepan with remaining sugar on grill; stir in 2 cups of water and whisk over the heat until dissolved into a syrup. Let cool.
- Place lemon and lime halves sugared-side down on grill and cook until browned, about 5 minutes.
- Place lemon and lime slices on the grill; cook until browned, 30 to 60 seconds on each side.
- Juice halved lemons and limes into a large pitcher. Add syrup and 2 cups water to the juice, 1/2 cup at a time, until the limeade achieves desired sweetness. Pour limeade into glasses filled with ice; garnish each glass with a grilled citrus slice.