Directions
In a medium-size, nonreactive bowl, combine the lemon juice and sugar and stir until the sugar has dissolved. Wash the basil leaves very carefully, then add them to the lemon-sugar mixture and gently crush the leaves against the sides and bottom of the bowl using the back of a spoon, or, better, a cocktail muddler. Taste the mixture. If you desire stronger basil flavor, add more leaves and crush.
Pour the mixture into a large glass pitcher, add the water, and stir. Serve in tall glasses filled with ice cubes. For a bit of bubbly, top each glass with a splash of effervescent seltzer water. Or add 3/4 oz (about 1 1/2 tablespoons) citron vodka or Limoncello to each glass, pour in the lemonade, and stir.