Peel lemons thinly using a vegetable peeler, discarding any white pith.

Combine lemon peel and vodka in a sterilized 1-quart bottle and seal.

Store the bottle in a cool, dark place for six days, shaking once a day.

Prepare the sugar syrup by combining sugar and water in a medium saucepan.

Stir the mixture on high heat until sugar dissolves, avoiding boiling.

Bring the mixture to a boil, then remove from heat and let it cool completely.

Strain the vodka mixture through a fine sieve into a large bowl or jug, discarding the peel.

Stir the cooled sugar syrup into the strained vodka.

Pour the limoncello into sterilized bottles and seal immediately.

Label and date the bottles.

Refrigerate until cold before serving.