Using a vegetable peeler, remove the skin from the lemons, avoiding as much of the bitter pith as possible. Juice the lemons and save the juice for another use.

Using a paring knife, carefully remove any excess pith.

Place the peels in a large jar (at least 56-ounces) and add the grain alcohol.

Cover and “steep” in a cool, dark location until the lemon peels are very pale yellow, for 1 to 2 weeks.

Strain the liquid and discard the peels.

In a medium saucepan, warm 2 ⅔ cups filtered water and the sugar over medium-high heat, stirring often, until the sugar is completely dissolved; cool completely.

Add the sugar water and an additional 4 cups of filtered water to the lemon liquor and stir to combine.

Portion the limoncello into bottles and allow to “cure” in the freezer for at least one week before serving.