Fernet Branca is a dark, oily alcoholic drink similar to an amaro, but less sweet. The flavour might best be described as being a cross between medicine, crushed plants, and bitter mud. Like most strong drinks in Italy, Fernet is usually drunk at the end of the meal as a digestive aid. It's also a popular hangover cure when added to an espresso: you'll often hear people ordering a caffè corretto con Fernet in coffee bars on the way to work.
The exact recipe of Fernet Branca is a secret but the producers, Fratelli Branca Distillerie, do say that it contains 27 different herbs and spices taken from four continents. Among the known ingredients are aloe, gentian root, rhubarb, gum myrrh, red cinchona bark, galanga and zedoary. The rumoured ingredients include saffron.