Cocktails with Lots of Non-potable Bitters
Many of the definitive cocktails from both vintage and modern times are held together by non-potable bitters - infusions of various barks, roots, spices, and other flavoring agents that were traditionally developed as medicine. Before Prohibition (but after the cocktail had been well-established), this usually meant Angostura, Peychaud's, Boker's, or orange bitters, which were key ingredients in drinks like the Manhattan, the Sazerac, and - despite what Winston Churchill said - the Martini.