4 thick skinned unwaxed lemons, 3 cups vodka (675ml), 1 cup granulated sugar (200/225gr)
Soak lemons 1/2 hour in cold water, remove and dry. Use veg peeler to skin lemons with NO pith. Put peels in Kilner jar, add 2/3rds of vodka. Close lid and stand in dark place 72 hours.
Combine 2 cups (450ml) cold water with sugar in saucepan over medium heat till boiling; remove from heat, allow to cool 2 hours. Add this mixture to jar and mix well. Filter through several layers of paper towel into clean jar, replace lemon peels, add last cup of vodka.
Close lid; stand in dark place 36 hours. Filter again, discard lemon peels, let stand for 1 week before using.
This is from The Taste of Italy by Giuliano Bugialli, and it really works.