Fernet Branca Liqueur
This amaro seems innocuous at first, with its coffee-brown hue and mild, root-like aroma. But it's intensely bitter from the first sip-so much so that it's hard to detect other flavors, though there's a bitter espresso and unsweetened chocolate core, plus a minty finish. Bartenders love to offer this uber-bitter liqueur as a shock-value shot; it's challenging to sip straight, even though the alcohol level is moderate. But it's also a key component of some classic drinks, like the Hanky Panky, and that's where its value lies.