from: Martha Stewart's Handmade Holiday
11 lemons, preferably organic
1 liter 160-proof vodka or grain alcohol
3 C sugar
3 C boiling water
Peel strips of zest from lemons using vegetable peeler; reserve remainder of lemons for another use. Put the zest and vodka into an airtight container and let stand at room temperature at least 2 days and up to 1 week.
Stir together sugar and hot water until completely dissolved; let cool completely. Stir sugar mixture into vodka mixture; refrigerate in an airtight container overnight.
Pour liquid through a large sieve and funnel into airtight bottles. Discard zest. Limoncello can be kept in the freezer for up to 3 months.