Lime Zest Cooler

This Agua Preparada de Limon Rallado is from the Rick Bayless book Authentic Mexican
 
8 large dark-green limes (the color is important)
¾ to 1 cup sugar

Using a fine, rasp-like grater (not a citrus grater) remove the lime’s green zest (no white). Add 1 quart water, using a little of it to rinse into the bowl any zest that has clung to the grater. Let stand 1 hour. (Wrap up the fruit for another use.)
Strain the zest mixture through a fine-meshed sieve, pressing firmly on the solids to extract as much liquid as possible. Add enough sugar to sweeten the drink to your taste, stirring until dissolved. Cover and refrigerate until serving time. Serve over ice.
Makes about 1 quart.

Results: Yummy!  Interestingly lime-y, though mine was a little too sweet.  It was a cool color, too with the bright green.  I forgot to photograph it but I'll definitely make this again.