Pat Heist is a total geek, but you might not know it at first. A long beard, leather jacket, and Kentucky drawl make him seem like he’s about to ask you to hold his beer so he can deliver a wailing guitar solo or ride a flaming motorcycle over a big jump. But it doesn’t take long before any conversation with Heist pivots from whiskey and rock ’n’ roll to topics like the deacidification of tannins or the small but critical difference between glucose and galactose — a distinction it’s clear he could expound on at length and with conviction.
Born and raised in Kentucky, Heist began his career as a university extension plant pathologist, where he could put his doctorate in microbiology to good use. After a stint working as a medical school professor of pathology, he got interested in moonshining. Before long, he realized his expertise in bacteria could be applied directly to making booze, and he made the professional leap. Today, he’s at the helm of Wilderness Trail Distillery in Danville, Kentucky. Much like Heist himself, the distillery is devoted simultaneously to the heritage of Kentucky distilling — and the possibilities unveiled by serious science.
From Consulting to Campari
Heist’s first — and by all counts, successful — venture in the distilling industry was as a principal of Ferm Solutions, a consulting company he founded in 2006 with his former bandmate and business partner Shane Baker specializing in the technical aspects of distillation. Before long, Heist’s skills were in such demand that he hit the road nearly full-time, visiting distilleries in technical distress around the world.
It was quite an education — one he decided to leverage in 2012, when he and Baker co-founded Wilderness Trail Distillery. Initially launched as an educational tool for clients, the business had relatively humble beginnings, producing about a half barrel a day on their 200-gallon pot still. But with the whiskey boom picking up steam, Baker and Heist started getting contract production inquiries from their Ferm Solutions clients. That cash flow helped capitalize their initial expansion to an 18” column still in 2016. “We still felt overstretched,” recalls Heist, “even with great staff.” While figuring out how to recapitalize, they developed a relationship with Campari, which acquired a 70% stake in Wilderness Trail in 2022 and fueled a major expansion.
Today, Wilderness Trail sprawls across a 168-acre property in Danville where 250,000 barrels are quietly slumbering in an ever-growing number of warehouses. A new one pops up about every three months. “I can’t believe it every time I drive down the road and see the rickhouses,” says Heist. Ferm Solutions is still firing on all cylinders — Heist estimates they’re working with about 150 distilleries that are yet to open — and he’s feeling optimistic about a future of better whiskey through science.
Balancing Tradition with Innovation
In many ways, Wilderness Trail is a hyper-traditional Kentucky distillery. Wheated bourbon and rye are its twin stars. Whiskeys are distilled on a Vendome column still, then aged in flat black rickhouses spaced evenly across rolling green hills. There’s a tasting room packed with merch, workshops on how to make smoked cocktails, and an annual barbecue festival that snarls traffic for miles around.
But Heist, Baker, and their team aren’t afraid to diverge from tradition when science points in another direction. Take their cookhouse, for instance. Bourbon tradition calls for cooking the mash at near-boiling temperatures. But at Wilderness Trail, the hottest the mash ever gets is 185°F, the temperature at which starch gelatinizes, or is able to dissolve in the water. “Why does everyone cook at 211 or 212?” muses Heist. “It’s just something that’s always been done. Maybe grandpa didn’t have a glass thermometer with him in the woods, and then we go to write his recipe down: ‘You boil the water.’ And that just perpetuates over time.”
The lower temperature has a number of benefits. Most obviously, it reduces energy use. But it also has an important impact on production. Near-boiling temperatures not only release starch from the grains, but also denature some of the proteins within the grain. Those free amino acids can be used by the yeast, which then produce a range of congeners including arginine, a precursor to ethyl carbamate, as well as others with off-flavors. “We’re cooking more gently to not break apart all those proteins and get congeners we don’t want,” Heist explains. “And also we’re saving boatloads of money.”
Control Freaks
Departures from tradition continue through to fermentation. All of Wilderness Trail’s whiskeys are made using a sweet mash technique. “We’re not trying to say sweet mash is better than sour, just that it’s different,” says Heist. That means Wilderness Trail doesn’t add backset to the fermenting mash to control the pH, instead relying on close monitoring of each batch to manage fermentation.
“Microbiology is all about control,” says Heist. But controlled doesn’t necessarily mean pristine. Wilderness Trail’s wash ferments in open fermenters, which means some batches inevitably get some sort of bacterial contamination. That’s intentional. Heist believes that bacterial cultures are key to flavor innovations, because the organic acids that bacteria produce are important precursors for later ester formation. Heist even hypothesizes that certain bacterial cultures that arise during fermentation are responsible for exceptional barrels or batches of bourbon. “Maybe microbiology [for whiskey] is kind of like the vintage of a wine,” says Heist.
The problem with bacterial cultures is that they compete with yeast for nutrients. That means robust bacterial cultures can reduce ethanol yield, cutting into production volume. So far, distillers have had to make compromises. But Heist imagines a future where better monitoring, records, and techniques will make it possible for distillers to get the flavor contributions of bacteria without sacrificing profitability — and the path to that future is microbiology.
Heist maintains a library of around 18,000 bacterial cultures drawn from Ferm Solutions clients as well as Wilderness Trail ferments, each one tied to a finished product or a spirit still in barrel. The goal is to be able to identify exactly which bacterial cultures were present in the ferments of spirits that turn out to be exceptionally delicious in the years or decades to come and then replicate that delicate balance for future batches. “We have some distilleries where we have bacteria going back 20 years,” says Heist.
Getting the benefits of bacteria isn’t necessarily as simple as tossing some in the fermenter and hoping for the best. “You sometimes have to go through some really delicate rearing procedures,” Heist explains. To avoid the reductions in yield that bacterial contaminations can create, Heist proposes a different approach: Grow up a batch of the specific culture that was present all those years ago, then steam kill the bacteria before adding their dead cells back to the larger ferment. Even without the activity of live bacteria, the amino acids in their cell structure contribute much the same character to the final product, resulting in flavor without loss of yield or unpredictability.
“This is where cooperation between distilleries matters,” says Heist. “We’re lucky because, through Ferm Solutions, we had access to the inside scoop of a lot of distilleries. We’re keeping their information confidential, but [the microbe library] is not really going to benefit any one distillery. The entire industry really needs to have this type of information. People need to know it.”
No Shit
Another innovation with potentially industry-wide implications at Wilderness Trail has to do with wastewater management. While working with a dairy through Ferm Solutions, Heist encountered an ultrafiltration system used to dewater cow manure. The water it produced was clean enough to require no additional processing. “If you can pull clean water out of cow manure, immediately stillage came to our mind,” says Heist.
About three years ago, they installed the equipment at Wilderness Trail. The technology isn’t new — it was invented in the middle of the 20th century — but using it at a distillery is, and it’s been a process of trial and error. “We’ve reengineered this thing multiple times to get it where it’s at now,” says Heist. But he still thinks it has the potential to radically alter wastewater management in distilling. “We generate about 100,000 gallons of stillage each and every day,” explains Heist. “When it’s working right, we pull about 40,000 to 60,000 gallons of water out of that with our system.” The output water can be used for the distillery’s boiler system, or, after passing it through a reverse osmosis system, it can be drinking-quality clean.
Despite Wilderness Trail’s commitment to innovation, it’s clear that tradition still looms large for Heist. “I am bona fide the biggest whiskey fan in the world,” he says. Heist marvels that Kentucky bourbon luminaries like Lincoln Henderson of Brown-Forman and Angel’s Envy, Dave Scheurich of Woodford Reserve, and Steve Thompson of Kentucky Artisan Distillery have all come to visit Wilderness Trail. He smiles when he describes walking into his first Kentucky Distillers’ Association meeting and seeing Jimmy Russell. “I thought, hell yes, I’ve died and gone to heaven, I’m allowed in the room with the masters.”
