Step 1Remove the yellow part of the lemon peel with a sharp peeler or fine grater, carefully avoiding the bitter white pith. If any pith remains on the back of a strip of peel, scrape it off.
Step 2Put the yellow peels in a jar or bottle, add 1 bottle vodka and seal tightly. Leave the bottle to steep until the peels lose their color, at least 2 weeks.
Step 3Put the water and sugar in a saucepan and boil until it turns clear. Let the syrup cool.
Step 4Strain the vodka from the peels and mix it with the remaining bottle of vodka and the syrup. Put the liqueur in bottles, seal tightly and let the components marry for at least 1 week before using. For drinking straight, store the limoncello in the freezer.