How did this barroom staple end up in the medicine cabinet? Apparently, around the turn of the 20th century, makers of Rock and Rye blurred the line between remedy and refreshment. Bottled versions made by Charles Jacquin et Cie (in production since 1884, the only pre-Prohibition survivor), Tolu, Arrow, Koch's, and Rocko-Ryo were often patented as "alcoholic medicinal preparations." This way, producers could skirt disapproval from the temperance movement while avoiding the higher taxes placed on liquor.
After Prohibition, bartenders resumed making their own. The best-known was Harry Craddock's, from the 1930 Savoy Cocktail Book, which simply called for dosing whiskey with rock candy and lemon. In recent years, barkeeps have even started adding it to cocktails. In San Francisco, Rye bar's version, made with citrus peels and cloves, spices up an old-fashioned. Star anise and horehound in the Rock and Rye at The Whistler in Chicago give the bar's hot toddy an herbal kick.