Limoncello is an Italian lemon liqueur that is mainly produced in Southern Italy, particularly in the region around the Gulf of Naples, the Amalfi Coast, and Sicily. It is the second-most popular liqueur in Italy and is traditionally served chilled as an after-dinner digestivo. Limoncello is made from the zest of lemons and usually has a slightly turbid appearance, which originates from the presence of small essential oil droplets suspended in the drink. The lemons used in limoncello must be untreated, and the peel (without the bitterish white part) should be thoroughly cleaned and left to infuse with the alcohol for at least 6 days in an airtight jar. In the meantime, a syrup of water and sugar is prepared, and then, when the 6 days have gone by, the alcohol in which the peels were macerating is filtered and added to the syrup. They are mixed together, and the liqueur obtained is poured into glass bottles and hermetically sealed. Limoncello is also a popular homemade liqueur, with various recipes available online and in print. It is commonly served straight and chilled after a meal, called a digestif or digestivo, but it can also be used in cocktails where it adds a lemon candy-like flavor. Limoncello can range from very sweet to super tart and citrusy, depending on the makers preference.