Limoncello is a typical Italian (more specifically, from Campania) lemon liqueur.
Experts use to select the lemons with the thickest zest, usually from Amalfi coast, Sorrento and Cilento area, where lemons usually have thick and super-fragrant peels. Then they wash them in warm water and brush to remove any dirt or pesticide traces. Then they cover the zest with pure Alcohol.
Lemon cultivation is not difficult, but lemon trees are quite sensitive to cold, so you need to protect them from frost and guarantee a good sunlight exposition. Citrus generally ripens in winter, and lemon is not exceptional.
In cooking, it is quite easy to make at home. You just need to be careful and choose the best organic lemons, possibly from Sorrento, and respect the infusion timing.
Fun fact: Limoncello has an old hostiry, made of legends and anectodes. We know it was born in a garden of Capri, at the beginning of XX century. It fast spread and bgan to be served in the bars all around the isle, and then along the Amalfi coast. Today it also has the IGP (Indicazione Geografica Protetta, protected geographical indication) denomination.
Here you have the recipe to make it at home: Limoncello