In a medium sized saucepan, heat sugar, 2 cups water and zest over medium heat. Bring to a lively simmer, not a boil, for about 8-10 minutes or until the syrup becomes a light yellow color from the zest. Turn off heat.

In a large pitcher, add lemon juice. Strain syrup with a mesh sieve into the pitcher to catch zest. Pour in remaining water. Taste for sweetness and tartness. Too sweet, add water. Not enough tartness, juice another lemon.

Serve with ice.