Trevor Bowles was walking the grounds of the Maker’s Mark Distillery one day in the spring of 2019. He had just been hired as what the brand calls a “bourbon diplomat,” essentially a brand ambassador for the near-70-year-old whiskey company. And that’s why he was wandering the Loretto, Ky., campus, familiarizing himself with everything that makes up the National Historic Landmark — its limestone cellars, the double-barrel copper stills, the hand-operated Chandler & Price printing press dating back to 1935, and all its charming Victorian-style buildings painted black with red shutters.

Across the way from Star Hill Provisions, the distillery’s restaurant and bar, Bowles stumbled upon a small garden. There, things like pumpkin, squash, corn, okra, watermelon, and tomatoes are grown to be used in the restaurant’s farm-to-table dishes and as infusions and garnishes for its house cocktails. But he quickly keyed in on a plant that seemed a bit out of place, though one he was more than aware of from a lifetime lived in the craft beer mecca of San Diego.

“Are those hops?!” he asked.

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Never Questioned

When Denny Potter first joined Maker’s Mark as a quality manager in 2003, he immediately noticed that retiring master distiller Steve Nally seemed to have every part of the esoteric production process stored in his brain, and nowhere else.

“The first thing I thought was, ‘We got fucking nothing written down,’” says Potter, who often speaks in a colorful tongue.

Poised to one day take over distilling operations — he actually became master distiller in 2018 — Potter wanted to more formalize the distillery’s production guidelines, or at least put things down in a simple Word document. So he asked Nally to take him through each process several times, especially when it came to propagating yeast — the first step, and arguably the most vital, for creating their signature bourbon.

Yeast is needed to ferment anything that will one day become alcoholic. Many distilleries buy commercial yeast, often sold in a dry, powdered form, but some, like Maker’s Mark, continually propagate their own house yeast; in other words, intentionally increasing the volume of yeast as needed so that the same, initial strain never dies. Potter followed along with Nally’s steps, which, toward the end of the process, included adding hops.

“I question a lot of things, but I’ve never questioned that,” says Potter. In fact, he claims our interview is actually the first time he’s ever been asked about it in his entire career. “I knew why [Nally] used them — why somebody would have even known to use them. Because hops acts as an antimicrobial,” he explains.

If today hops are mainly seen by the layman as what provide the incredible bright, fruity, and sometimes piney and dank aroma and flavor present in beers, and especially IPAs, they’ve long had a dual purpose as a preservative. The high concentration of what are known as iso-acids present in hops prevent bacterial contaminations that could radically change the flavor profile, if not ruin a beer — or whiskey.

“It’s been known for a long time that the addition of hops will control the growth of bacteria in beer,” Matt McCarroll, professor of chemistry and biochemistry and director of the Fermentation Science Institute at Southern Illinois University, told Porch Drinking last year.

While these antibacterial qualities aren’t necessarily needed at a modern distillery with an emphasis on cleanliness, why take the chance? Potter claims that cluster hops from Washington State — which are 7.5 percent alpha acid — are deployed in pellet form during the initial phase of propagation, when trying to disinfect the yeast.

“I don’t have to order them a whole lot, because we don’t use a ton,” says Potter, though it’s enough to fill the room with the distinct aroma of hops every time it’s added. Potter claims he orders a pallet of these hops maybe twice a year. (To be clear, Potter says that though the distillery garden may grow fresh hops, those plants aren’t typically used for their yeast propagation these days.)

“I don’t know of anybody else in distilled spirits who uses hops,” he says.

Who Knows?

Was this true? Why had I never heard about this before? Why had no one written about it before? Was it possible that hops, and not Maker’s Mark’s unique wheated mash bill, was the secret to its iconic flavor profile?

If you know bourbon brands, they love to tout the familial, historical, and sui generis nature of their house yeasts, but it can be tough to separate fact from puffery. On Maker’s Mark’s website they claim “an heirloom yeast strain that’s more than 150 years old” and has been used to create every single bottle the brand has ever produced. Potter has no idea if that is actually true, but he confirms that it’s been there at least as long as he has.

“There’s a lot of truth in these old stories,” he explains. “In my experience, [our yeast] is three generations old at a minimum. Did they get it from ‘Pappy’ [Julian Van Winkle, III, who also made a wheated bourbon], did they borrow it from Beam? Who knows?”

I finally tracked down Steve Nally, Potter’s aforementioned mentor and now a septuagenarian, who started at Maker’s Mark as a night watchman in 1972. The distillery was already using hops by then, he recalls. Nally claims they would get “bales” of fresh hops from Washington State; the hop cones were ground weekly, then used at the beginning of the propagation process. Just a small amount was added to the dona jug where the mother yeast was stored.

“The aroma from that was wonderful, kinda like ground coffee, when you first grind it, though the hops were 10 times more [aromatic] than that,” Nally recalls. “I was so new to the process, to the industry, that I didn’t question it. Sam Cecil was the plant GM, he was a chemist, and such a smart guy that anything he did I really thought was just industry standard.”

In fact, Nally believes Maker’s Mark has used hops since day one of 1953 when it was founded, attributing the origins of the practice to either Cecil or the Samuels family that started Maker’s Mark. Though, admittedly, other distilleries of the era employed the practice as well.

“[It was] not ubiquitous but common, even more common in the yeast mashes ‘practical’ distillers used to catch wild yeast,” explains Chuck Cowdery, a bourbon historian and author.

You Shouldn’t Need It

Whatever the case, it’s not a technique that is still prevalent today, whatsoever.

Upon coming out of retirement to work for craft upstart Wyoming Whiskey in 2007, Nally didn’t continue the practice, instead utilizing commercial yeast. Nor does he deploy hops today as master distiller of the Bardstown Bourbon Company. He just doesn’t think it’s necessary.

“An older facility like Maker’s has so many cracks and crevices in and around the building, so much wood for bacteria to grow in. It can be tough to keep clean,” says Nally, comparing it to the pristine Bardstown Bourbon that is mostly made of stainless steel and concrete.

But, as Potter notes, Maker’s Mark today has such high-tech laboratories that there is little fear of accidental bacteria problems. Dr. Pat Heist, a fermentation expert, agrees that the use of hops is a relic from the past that is just no longer needed.

“Most distilleries, outside of fuel ethanol plants, dry pitch yeast (add active dried yeast directly to the fermenter), so they don’t have propagation tanks,” explains Heist, co-owner of Wilderness Trail Distillery and FermSolutions, which supplies yeast strains and fermentation products to breweries and distilleries. Among the hundreds of distillery clients he deals with, he knows of none that add hops. “Maker’s and Beam are exceptions,” he says. “If you keep your tanks clean, you shouldn’t need any antimicrobials, including hops.”

Yes, as Heist hints at, Jim Beam also uses hops in the propagation of its yeast. A fact all the more curious when you consider that Maker’s Mark has also been owned by Beam Suntory since 2005 (after being owned by Hiram Walker & Sons from 1981 until 1987 and Allied Domecq from 1987 until 2005).

“This process has been documented as far back as 1935 and we’ve been using the same yeast strain since,” claims Freddie Noe, the distillery’s eighth-generation master distiller. Other than those two, however, I really wasn’t able to find any other whiskey distilleries currently using hops, even if they propagate their own yeast like, say, Wild Turkey.

Still, Nally doesn’t ever see Maker’s Mark scrapping the practice. No one I spoke to, including Nally, felt that the hops influence the flavor profile of Maker’s Mark. But he also doesn’t think anyone wants to actually find out for certain.

“I think, for whatever minute influence the hops might have on the product, it’s something that you don’t want to change because it might affect it,” he says. “It’s been done since they started and even with all the different companies that have bought Maker’s out, no one has said, ‘Let’s cut out the hops.’”

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