3 cups water
1 cup freshly squeezed lemon or lime juice
½ cup sugar or sugar syrup
Combine the water and lemon or lime juice with sugar syrup to taste.
(To make sugar syrup, mix 2 cups water and 2 cups sugar in a pot and cook on medium, stirring occasionally, until the sugar is dissolved. If you don’t use it all in the lemonade, you can add it to other beverages needing sugar, such as iced tea.)
Source: How to Cook Everything by Mark Bittman