Wash the lemons with a vegetable brush and hot water.
Carefully zest the lemons with a zester or vegetable peeler so there is NO WHITE pith on the peel.
White pith will leave a bitter taste.

In a clean (sterilized) glass jar, add ½ of the bottle of vodka and the lemon zest.
Cover the jar and let it sit at room temperature for at least 10 days up to 40 days in a cool dark place.

After the 10-40 days, prepare the simple syrup.
Combine the sugar and water and cook until thickened, about 5-7 minutes.

Let the syrup cool before adding it to the Limoncello mixture.
Add the additional ½ bottle of River Pilot Vodka.

Allow to rest for another 10-40 days.

After the rest period, strain the zest and discard it.
Bottle the liquid and keep in freezer until ready to serve.