Since people first started making bourbon, arguably the easiest part of the whole production process has been selecting the type of barrel used for aging the whiskey.
As decreed by the United States Congress in 1954, bourbon must be aged in a new, charred American oak container. Most distillers opt for the standard 53-gallon American white oak barrel, add their spirit to it and, after a few years, bottle the whiskey.
However, as Jefferson’s Bourbon founder Trey Zoeller discovered not long after launching the brand with his father in 1997, sticking only to this traditional aging method doesn’t allow for much innovation or excitement. His hope was to make whiskey that truly pushed the conventional boundaries of bourbon.
Around the time Zoeller began developing his globetrotting lead innovation bourbon Jefferson’s Ocean, he also became increasingly interested in how he could finish his whiskey in other types of barrels. This led him to visit the Independent Stave Company (ISC) in Lebanon, Missouri.
“I saw what they had learned over the last 100 years of being in business and the technologies that they were incorporating,” remembers Zoeller. He was particularly interested in the possibility of going beyond the standard options for charring the inside of a bourbon barrel. After the experience, “I thought, ‘Why are we so rudimentary in bourbon that we’re only using four levels of char?’”
That visit, and the many more to come, set Zoeller on a path to understanding how the type of wood and the different kinds of barrel treatments, from toasting and charring to texturizing, could be used to alter the flavor of bourbon. One of his favorite successes from these experiments was the Jefferson’s Reserve Twin Oak, a 10-year-old bourbon finished in barrels he developed alongside ISC coopers.
“These barrels, I extra seasoned outside in the cooperage yard for about 18 months, then we grooved them out so the inside of it looks like a ridged potato chip,” says Zoeller. “That gives you twice as much surface area to touch the liquid. We put a flash char on it to kind of open it up. Then we toasted at a certain time and temperature, which brings out mocha flavors.”
Following a visit to a winery in Missouri, the whiskey maker decided to push this idea even further. He wondered how the different wood treatments used by wineries would affect the bourbon. So he decided to test this out by finishing four-year-old bourbon in 13 different types of barrels for 32 months. He released the five best of these trials as a collection of mini-bottles called the Wood Experiments.
“I always say I’d never want to develop a product out of the boardroom,” says Zoeller. “I’ve been lucky enough to collaborate with a lot of people.”
When it comes to finishing his whiskies in used barrels, rather than using the relatively common sherry or Port casks, he’s found success collaborating with winemakers and distillers who make products he enjoys drinking.
“It’s flavors that I want to put together, that I like, that I think would come together—not what’s available or what’s been done traditionally,” says Zoeller. “I’m tasting what’s in there beforehand and then going to the wineries or to the distilleries and speaking to them and telling them, ‘Hey, I’d love to work together on this with you, would you all like to partner with us?’”
To that end, Zoeller has partnered with a handful of wineries working with big, bold Cabernets to showcase how their unique flavors can influence bourbon. That includes Napa Valley winery Pritchard Hill, as well as French wineries Château Pichon Baron and Château Suduiraut.
“Even though it’s the same Cabernet grape, the earthiness that comes out of those Bordeaux Cabs versus the Napa Cabs is tremendously different,” he says. “We’re picking in this case wines that have very distinct flavors that come through in the bourbon.”
He’s also collaborated with Malcolm Gosling, Jr. of Gosling’s Rum to create Jefferson’s Reserve Old Rum Cask Finish—but the process of discovering that partnership’s potential was a bit more unusual. One evening, while having a glass of rum with Gosling, he had an idea.
“I’m a bourbon guy and after one rum drink it’s too much,” says Zoeller. “So I poured a glass half full of his Family Reserve Old Rum and half of Jefferson Reserve and together I thought the flavors were out of this world. So, I ended up finishing some bourbon in those old rum casks, and I thought that’s absolutely delicious.”
Of course, not all of his barrel experiments turn out so well. Though Zoeller loves spicy foods, an experiment finishing bourbon in a used hot sauce barrel didn’t work out. “It would have blown your head off because the seeds were stuck in the staves.”
But Zoeller says that’s the fun—you never know exactly what combination of factors is going to produce the next exceptional bourbon or how long it will take to get there.
“It’s an evolution,” says Zoeller. “The exciting part of maturation for me is you don’t know exactly what it’s going to taste like. Some of the experiments that you don’t think are going to be the winners come out as the shining stars.”
Please sip responsibly