Zest the lemons and place the zest in a large glass jar or bottle.

Pour the vodka over the zest, making sure it covers the zest completely.

Seal the jar or bottle and store it in a cool, dark place for at least a week. You can leave it for up to a month for a stronger infusion.

After the infusion period, strain the mixture through a fine-mesh strainer or coffee filter to remove the zest.

In a small saucepan, make a simple syrup by heating equal parts water and sugar until the sugar dissolves. Let it cool to room temperature.

Add the sugar syrup to the infused vodka and stir well.

Pour the limoncello into swing top bottles or other airtight containers.

Store the bottles in the freezer for a few hours or overnight before serving.