Limoncello

1.Zest the lemons, and place zest into a large glass bottle or jar. Pour in vodka. Cover loosely and let infuse for one week at room temperature.
2.After one week, combine sugar and water in a medium saucepan. Bring to a boil. DO NOT STIR. Boil for 15 minutes. Allow syrup to cool to room temperature.
3.Stir vodka mixture into syrup. Strain into glass bottles, and seal each bottle with a cork. Let mixture age for 2 weeks at room temperature.
4.Place bottled liqueur into the freezer. When icy cold, serve in chilled vodka glasses or shot glasses.