The Old Fashioned cocktail is aptly named. You can arguably consider it the archetypal cocktail that has best stood the test of time. Quite deservingly, the Old Fashioned is often claimed as one's "favorite" cocktail. Let’s take a look at what makes it such a great drink.
It’s one of the oldest cocktails. Consider George Kappeler’s 1895 book Modern American Drinks first recorded reference to the “Old Fashioned Whiskey Cocktail”:
Dissolve a small lump of sugar with a little water in a whiskey-glass; add two dashes Angostura bitters, a small piece of ice, a piece of lemon-peel, one jigger whiskey. Mix with a small bar-spoon and serve, leaving spoon in the glass.
In fact, there are plenty of reasons to believe the drink had been around in its essential form much earlier than Kappeler’s official recording, but the key point here is that the Old Fashioned is very old indeed.
It’s simple. Consider the essential makeup of any cocktail: a combination of spirit, bitters, water, and sugar. The Old Fashioned is the sum of these parts, in perfect balance, and nothing more. Given the base spirit, the bitters are just enough to accent the flavor, the syrup is just enough to round the spiciness of a good rye whiskey, and the ice is just enough to dilute and chill the drink appropriately. In some sense it’s the least pretentious cocktail, due to its simplicity.
It’s delicious. No matter how old and simple the Old Fashioned may be, what it truly has going for it is excellence. As with any drink that is so straightforward, you’ll want to use the good stuff, because each ingredient is going to come through significantly. Use a quality rye or bourbon whiskey, a good sweetener free of high fructose corn syrup, and a classic bitters like Angostura.
It’s a template. In Kappeler’s book and many others, the “Old Fashioned” cocktail was originally specified with the drinker’s desired base spirit. For example, gin Old Fashioneds and brandy Old Fashioneds stood right alongside the whiskey Old Fashioned as bar staples. The basic recipe and instruction remains consistent for different base spirits, meaning even rum Old Fashioneds, pisco Old Fashioneds etc. are all worth a try. In essence, think of the Old Fashioned cocktail not as a singular whiskey drink, but instead as the old fashioned way of making cocktails.