The taste of Tennessee whiskey is distinct.
“There are different degrees of toast which elicit different flavors into the whiskey,” says John Munafo, standing in a Food Science lab at the University of Tennessee Institute of Agriculture. “This is considered a char, which is basically a light roast. Then we have more of a dark char, which is more burnt that elicits a more smokey type attribute and some vanilla like attributes, as well.”
The flavors created by the varying degrees of char seem to flow in Tennessee-created whiskey, and it’s what unlocks an unforgettable experience.
“For Tennessee whiskey, there’s a standard of identity,” says Muanfo, who is an assistant professor of flavor science and natural products chemistry at UT. “The mash bill has to be at least 51% corn.”
The corn-based beverage is big business, as Tennessee is not only one of the top whiskey producing states in the country, but whiskey is also one of Tennessee’s major exports. The taste of Tennessee whiskey is also backed by science.
“My current appointment is about 50% flavor science and 50% natural products chemistry,” says Munafo.
The appointment has turned him into a bit of a whiskey connoisseur, but one with a scientific mission.
“On the flavor science side, we try to understand the molecules that are responsible for flavor,” he explains. “On the natural product side, those are molecules that are from nature.”
Understanding the science behind this beloved drink didn’t happen by chance at the university.
“I had a student who was really interested in whiskey,” says Munafo. “He had asked him was he able to do his thesis on whiskey, and we wanted to focus on Tennessee whiskey.”
Searching for something unique, they found a process called “The Lincoln County process,” a key step in making Tennessee whiskey.
“In order to be labeled as Tennessee whiskey, the whiskey not only has to be made of at least 51% corn, it has to be made in the state of Tennessee and has to be aged in charred, unused oak barrels for two years after going through this process called the Lincoln County process.”
Munafo says the Lincoln County process is a charcoal filtration step, but it’s one unique to the state. It’s also a key step in helping to create the taste that’s led to growth of the state’s thriving industry.
“It’s believed that this process imparts a smoother flavor to whiskey,” he says. “However, there’s no scientific data to date on that.”
The science was unknown, as the process of making whiskey was more of an art.
“It’s a charcoal filtration process where a fresh distillate is passed through maple charcoal,” he says. “It’s believed to impart a smoother flavor to the whiskey. And the thing that’s really interesting about it is there’s no regulation on how it’s done: how much charcoal to use, how long it has to soak. So, all the distilleries have a different process, which is often shrouded in mystery.”
Munafo says the mystery was to understand the science behind the changes in flavor, all spurred by that one process.
“There’s a lot of different steps in the flavor formation chain, is what we call it, and they’re really unknown,” he says. “The recipe that’s used to ferment the grains, or the distillation process, which is the Lincoln County process, is not really very well understood.”
Munafo says by focusing on the science, not only are researchers peeling back the layers of mystery, but also allowing students to explore what creates the distinct taste found with Tennessee whiskey.
“We look at a lot of different aspects of aroma chemistry, as well as taste chemistry,” says Melissa Dean, a PhD student who works in the flavor science lab.
Dean and others are searching for answers to what makes Tennessee whiskey so tasty.
“My specific focus is on plant volatile,” she says. “So, I look at different compounds that plants produce to create aromas.”
The science isn’t simple, but it helps create an experience many have come to enjoy.
The aroma of whiskey is very complex,” says Dean. “It’s all produced throughout a lot of different stages of aging, which produce different aroma compounds.”
The complex cause is one even distillers are hungry to know.
“I got invited to talk with the Tennessee Distillers Guild, and it’s really interesting, because a lot of the distillers make fantastic whiskey, and it’s very consistent; however, there’s not a lot of science known,” says Munafo. “To help them to control their process better and create the targeted flavor profile they want, there’s a really big opportunity and that could really help the distillers along and the customers to get whiskey that they really enjoy.”
As researchers work to help Tennessee’s renowned industry continue to thrive, Tennessee-born whiskey can be found in every country around the world. That’s why the work at the University of Tennessee is rewarding research, helping support a flavorful Tennessee tradition.
