Swap Bourbon With Japanese Whisky For A More Complex Old Fashioned
The old fashioned is arguably the keystone of all cocktails. Its simplicity belies a deep understanding of the fundamentals of good mixology and provides a minimalist template bartenders can use to experiment on top of. A classic recipe will use whiskey as the base, a bit of simple syrup, and a few dashes of Angostura bitters. Stir it up over ice, garnish with a cherry, and pinch a slice of orange peel over the top to express the citrus oils over the drink.
Because of how small the ingredient list is, the choice of whiskey has an outsized impact on the overall flavor profile. Bourbon is a popular choice thanks to its inherent sweetness which produces a softer palate that goes down smoothly. But if you're already opting for an old fashioned, odds are that you enjoy a more spirit-forward drink and Japanese whisky is an excellent candidate for that pursuit.
While there are plenty of complex bourbons, Japanese whiskies are famously nuanced, balanced, and fruit-forward thanks to their distillation techniques and choice of wood for maturation such as mizunara oak barrels. There are several major Japanese whisky brands, each of which has worked hard to cultivate a particular style, so we are speaking generally on the topic. That said, there are a number of excellent Japanese whiskies that would fit perfectly into the old fashioned format.
Getting creative with the Japanese old fashioned
It's no secret that Japanese whisky makers are heavily inspired by the scotch whisky tradition. One way this manifests is in Japan's use of peated barley which is responsible for the iconic smokiness associated with scotch. Like scotch, not all Japanese whisky is peated but if you enjoy the earthy burn of peated whiskey then you can further mix up your next old fashioned by going for something smoky.
There are other ways you can amplify your Japanese old fashioned, though. The traditional method of crafting an old fashioned has you muddling a couple cherries and an orange slice before stirring the drink. This tastes great with any whiskey, but we think it goes really well with Japanese whisky's strong fruit notes.
As for the bitters, Angostura is essentially a non-negotiable so don't bother swapping it out for something different, but adding a few dashes of orange bitters as well isn't all that uncommon. If you have a small collection of cocktail bitters, feel free to experiment with what you have. This will be fairly dependent on which whisky you choose, so feel free to whip it up like normal, take a sip, think of what flavor you would like to pull out to the forefront, and select a type of bitters you think will do the job. Barrel-aged bitters could be fun but they may overpower the drink, but fruity bitters such as grapefruit or cherry would work well.