Beat the heat. “Fresh water” fruit drinks are an everyday accompaniment to meals in Mexico. Using local fruits of the season, they make a refreshing sipper to wash away the dry, dusty days. Ours is a little more elaborate, sweetening with an infused simple syrup, topping off with seltzer and adding a fresh garnish. We like to be fancy. Sometimes.
for the basil-lime syrup
Combine the sugar, water, basil leaves and lime zest in a small saucepan and bring to a boil over medium-high heat. Reduce heat to maintain a simmer and stir until sugar dissolves. Remove from heat and let syrup cool completely. Strain.
for the aqua fresca
Working in batches in a blender, puree the cantaloupe with the water, 1/2 cup basil-lime syrup, lime juice and salt until smooth. Strain through a fine mesh sieve and discard the solids. Taste and add up to 1/4 cup additional basil-lime syrup if you’d like it sweeter. Transfer to a pitcher and chill, or serve right away.
Fill 6 glasses with ice. Divide the agua fresca between the glasses and top off with sparkling water. Garnish with basil sprigs and lime slices, if desired.