Better Bartending 

Bitters

The botanical ingredients used in preparing bitters have historically consisted of aromatic herbs, bark, roots, and/or fruit for their flavour and medicinal properties, some of the more commonly used ones which have included cascarilla, cassia, gentian, orange peel, and cinchona bark.

 

Most bitters contain both water and alcohol, the latter of which functions as a solvent for botanical extracts as well as a preservative. The alcoholic strength of bitters varies widely across different brands and styles.

 

Angostura

Being the most common bottle of bitters behind the bar happens to be a good thing in the case of Angostura. While it lacks the bright spice of other aromatic bitters, it's a workhorse. Sometimes you want to add just enough bitter and aromatic quality—in the case of Angostura, earthy gentian and warm cinnamon notes—without overwhelming the other ingredients. Angostura also produces a nice, spicy, fresh, orange-forward orange bitter.

 

Peychaud's Bitters

This is the quintessential ingredient for the famous Sazerac cocktail. Apothecary Antoine Amédée Peychaud created them in the beginning of the 19th century. Bright red and lighter than Angostura, they share a base in gentian root. The combo of Peychaud and Angostura is formidable in such cocktails as the Vieux Carré. 

 

Regan's Orange Bitters No.6

While the field was still barren, cocktail enthusiasts were emboldened by the arrival of Regan's Bitters with famed bartender Gary Regan (and his beard) gracing the front of the bottle. Spicy and richer in character than most orange bitters, they also offer less sweetness and are a lightning rod in certain cocktails like the Martinez.

 

The Bitter Truth

The Bitter Truth offers a line of bitters created by German bartenders Stephan Berg and Alexander Hauck, including the famed Bittermen's bitters. The whole line is worth a look and notably complex, though expensive. The best of the bunch are their Orange, Celery, and Xocolatl Mole Bitters. 

 

Fee Brothers

Fee Brothers have become the most widely available of the more extensive lines but they are definitely a mixed bag. Their Old Fashion Aromatic, Whiskey Barrel-Aged Bitters, and Peach are not only delightful but bear a thousand uses; flavors such as Mint and Rhubarb are simply the better part of cough medicine. One great thing about Fee Brothers bitters is that they're non-alcoholic, so you can use them in non-alcoholic drinks, a.k.a. "mocktails."