Whiskey lovers tend to be particularly territorial about their spirit of choice. Here in America, these allegiances are especially present in whiskey culture.
All the different types of whiskey made in America have their unique pulls. Rye whiskey junkies will croon about its spiciness and burn, while bourbon aficionados will pore over the drink's smoothness and its vanilla and caramel notes.
Despite whiskey’s popularity, few studies have examined what exactly differentiates these spirits. A new report in the journal Food Chemistry focuses on the nonvolatile compounds that differentiate bourbon, rye, Tennessee whiskey, and American blended whiskey.
Authored by University of California, Davis chemist Thomas Collins, this study used samples of 63 different whiskeys to establish what exactly separates one type from another.
Within the U.S. and abroad, whiskey is a hot commodity. As a result, it’s inspired many counterfeits and imitations. One of the focuses of Collins’ study was to find markers for each type of whiskey that could potentially be used for authentication down the line.
During the course of this research, Collins and his team found almost 4,000 distinct compounds. For a complex spirit made from grains that are roasted, fermented, distilled, then aged, the number of compounds isn’t very surprising.
In the study, the team was able to narrow the field down to around 40 that were critical to the differences in taste among the spirits. “They weren’t necessarily the most important compounds, but they were important in differentiating the types of whiskey,” says Collins. “To really understand their impact requires some sensory input and then correlating the panelists’ findings with the chemical components.”
Out of the four, the American whiskey was easiest to separate. Since it’s usually aged for shorter periods of time, it’s not surprising that this type had few wood-related compounds. Tennessee whiskey, on the other hand, was somewhat separable from bourbons and ryes, but not by as much. It’s possible that this difference stems from the charcoal filtration process that most Tennessee whiskeys undergo after aging.
The differentiation between bourbon and rye is a bit harder. Though ryes from rye-focused distilleries were somewhat more distinct, “the ryes from major bourbon distillers tended to be more similar to the bourbons they produced,” says Collins.
Much of the similarity among these whiskeys may be due to the similarities of their mash bills (the makeup of grains used to make whiskey). By law, the mash bill of both bourbon and Tennessee whiskey must be at least 51% corn. Though rye’s must be 51% rye, the other 49% is often filled out with corn, making it very similar to the others.
Proof in the barrel
If the starting materials aren’t the cause of the differences in taste, what is? Chances are, it’s the whiskey’s time in the barrel. Therefore, it’s not surprising that ryes and bourbons from the same producer tend to be similar – the distillery is probably using the same types of barrels for the different types of whiskeys. According to Collins, scientists can compare whiskey that’s just been distilled with its aged components to figure out these differences.
Hit the Lab
To truly experience whiskey, it’s best to sip it neat or with one cube. However, a lot of classic and modern whiskey-forward cocktails can showcase the spirit without overwhelming it. One such cocktail is the Old Fashioned.
Though the gorgeously fruity concoctions showcased on Mad Men have re-popularized this drink, the Old Fashioned originally evolved out of the 19th century’s Whiskey Cocktail. At first, this drink (also called the Old-Fashioned, Old-Fashion or Old Fashion) was a simple tipple made up of sugar, bitters, and whiskey poured to the customer’s taste over one large ice cube.
Over time, this libation morphed into a class of cocktail rather than being a drink with a prescribed set of ingredients. An entire (and beautiful) book has even been written about this drink. Making your Old Fashioned to your own taste is more important than following an historical standard. Play around with whiskeys, sugars, bitters and garnishes, and once you formulate the perfect one for your tastes, you’ve got your own house Old Fashioned!
1 dash orange bitters
2 dashes Angostura bitters
1 tsp (or to taste) brown sugar syrup
2 oz bourbon
Combine all ingredients in a mixing glass. Add ice and stir until chilled. Strain into an Old Fashioned glass and garnish with an orange peel.
Read more about the difference between Scotch, Whiskey and Bourbon.