Limoncello is an Italian lemon liqueur mainly produced in Southern Italy, especially in the region around the Gulf of Naples, the Sorrentine Peninsula and the coast of Amalfi and islands of Procida, Ischia and Capri. It is also produced in Sicily, Sardinia, Menton in France, and the Maltese island of Gozo. Though there is debate about the exact origin of the drink, it is at least one hundred years old. Traditionally, it is made from the zest of Femminello St. Teresa lemons, also known as Sorrento lemons or Sfusato Lemons. Lemon zest, or peels without the pith, are steeped in grain alcohol until the oil is released. The resulting yellow liquid is then mixed with simple syrup. Clarity and viscosity are affected by factors like the relative temperatures of the two liquids. Most lemons, including the more-common Eureka lemon, will produce satisfactory limoncello.