Angostura; invented by Dr. Johann Gottlieb Benjamin Siegert, a German doctor in the mid-1800s was originally created to stave off dysentery and other debilitating afflictions of the digestive tract. This particular bitters (along with orange bitters) was, and still is, a popular and essential ingredient in classic cocktails, and although Angostura is the grandaddy of bitters, the number of brands now available on the market is overwhelming, with many serious cocktail bars making their own in-house bitters.