Before people started calling this an Old Fashioned, it was just a Whiskey Cocktail. Prohibition brought about a massive paradigm shift in the way cocktails were made. Prior to the ratification of the 18th amendment and the start of prohibition lightly flavored high quality spirits were popular among many drinkers. You can identify these vintage style American cocktails by a couple ounces of a base spirit that is lightly flavored with no more than 2 or 3 dashes of other flavorful ingredients and just enough sweetness to cut the spirits burn. With the start of prohibition in 1917 the quality of most liquor greatly diminished and high quality spirits were priced out of most peoples range, and most trained bartenders left the profession and got jobs that were not illicit. Suddenly over night there was a loss of quality product and knowledge. The cocktails that gained in popularity were the highball and sour style cocktails. Not to say they didn’t exist before this but prohibition had made them more popular. highballs and sours had the benefit of being slightly easier to make and having larger amounts of strong flavored ingredients that helped mask the taste of poor quality spirits. The epitome of this being the tiki drink. Which was created during prohibition and saw the first tiki bar open in Hollywood CA in 1933, immediately once prohibition ended. If an older individual wanted to order a whiskey cocktail like they remembered having prior to prohibition they would need to ask for a whiskey cocktail made in the old fashion. Keep in mind, prohibition lasted for 16 years, a person turning 21 in 1917 was now 37. An entire drinking generation had grown up not having access to these kind of cocktails.
Before prohibition the bitter used in this classic cocktail were Boker’s Bitters. Unfortunately the company that manufactured Boker’s Bitters was already on hard times in the early 1910s and with the start of prohibition they closed their doors forever. Those that knew the recipe ended up taking it to their graves. Angostura Bitters ended up replacing Boker’s since people were unable to get this classic ingredient or even find people who knew what it was made of. Oddly enough a bottle of Boker’s Bitters was found in the 2000s in a deceased man attic and the very old tincture was reverse engineered. It was found to be a primarily Cardamom bitter with other citrus and spices flavors. Since this discovery Cardamom bitters made in the Boker’s style have started popping up on store shelve.
The other lost ingredient was gum syrup which was replaced with standard simple syrup. It’s not that gum arabic disappeared but that gum syrup is really difficult to make and can take quite a while to fully emulsify. Untrained prohibition-era bartenders didn’t have the skill or patience to make an ingredient that most speakeasy drinkers didn’t even want.
The classic whiskey cocktail still taste strongly of bourbon and has very forward caramel and oak flavors, but the bitters add almost an Indian spice to it. The boker’s style bitters add a cardamom, cinnamon, herbal, citrus flavor that taste very much like traditional spices for Indian food. The small amount of gum syrup thickens the consistency giving the drink a velvet full body. the body is similar to that of a red wine. To me it’s completely different from a modern old fashion. I can see reasons for preferring one over the other as they are very different from each other and both are an acquired taste.
The Most Important Ingredient
The most important ingredient in a pre-prohibition style whiskey cocktail is the cardamom bitters. This one ingredient completely changes the direction of the drink. Angostura has a dark heavy, spicy, bark, earthy flavor but boker’s style cardamom bitters are bright and fragrant Indian spices and citrus flavors. The Gum syrup does play a nice role in changing the body to more of a milky full body red but normal simple syrup will still work fine, but it’s the bitters that define this cocktail.