2 cups lime juice, freshly squeezed
1½ cups sugar
1 2-inch piece of ginger, peeled and sliced
In a small saucepan over medium heat, add lime juice, sugar, and ginger, and warm until sugar is dissolved and syrup is infused with ginger. Strain, and cool.
To serve, fill a glass with ice, and add 3 to 4 ounces of lime-ginger syrup. Top with soda water. Stir, and serve.