Combine 10 lemon peels (peeled from the fruit in a single spiral, without any pith) and 1 gallon unflavored vodka in a lidded glass jar. Let sit at room temperature for 45 days.
Make a simple syrup: Combine 3/4 cup water with 1/3 cup sugar in a saucepan over medium heat and stir until dissolved. Cool completely. Strain the lemon-vodka infusion into a pitcher. Add simple syrup and stir.
Pour limoncello into a shaker with ice. Shake and serve cold in a sugar-rimmed glass with a
lemon wedge. (You can also divide the spirit into decorative bottles and give them as holiday gifts.)