Char lemons and limes
Build a medium-heat fire in a charcoal grill, or heat a gas grill to medium. Alternatively, you can heat a cast-iron grill pan over medium-high heat.
Place 6 halved lemons and 6 halves limes flesh-side-down on grill and cook until lightly charred in spots (about 30 to 60 seconds). At this time, you could also grill the lemon and lime wheels (around 20 seconds per side).
Juice lemons and limes to yield 4 oz. each of charred lemon and charred lime juice.
Make toasted simple syrup
Add sugar to a medium saute pan over medium heat and toast, stirring occasionally, until fragrant (2 to 3 minutes).
Let cool for 10 minutes.
Add 1⁄2 cup of water, return pan to medium heat, and stir until sugar is dissolved. Do not boil or simmer. Set syrup aside to cool; it will keep for months in the refrigerator.
In a pitcher, combine charred lemon juice, charred lime juice, toasted simple syrup, water, spirit (if using), and ice.
Stir until incorporated, and serve in Collins glasses over ice.
Garnish with lemon and lime wheels.
1⁄2 cup sugar
12 oz. cold water
7 lemons, 6 cut in half, 1 cut into wheels
6 limes, 5 cut in half, 1 cut into wheels
Makes: 4-6 servings
Takes: 10 Minutes