Fernet is a style of amaro, or bitter digestif, typically served after a meal with espresso in Italy. The Branca family's bottling is by far the most well-known example, based on a recipe dating back to 1845. While the exact formula is a family secret, its 27 herbs include quinine, rhubarb, chamomile, cinnamon, linden, iris, saffron, zedoary, galangal, and myrrh.