Andrew Faulkner Issue 13

Leopold Bros. goes analog

Todd Leopold

Rescuing a lost style of whiskey from the confines of history

Written by Andrew Faulkener

Todd Leopold has done the distilling equivalent of going back to vinyl; putting away the MP4s and earbuds, replacing the CD player with a turntable, ditching solid state for a tube amplifier and cranking up the vintage JBLs. 

For the devoted followers of this Colorado craft distillery, the release this spring of Leopold Bros Three Chamber Rye Whiskey is truly a whiskey geek’s dram come true. 

Leopold has turned back the clock 123 years, to 1898, when rye whiskey was thick in its heyday. That was the year when the US Internal Revenue Service commissioned researchers CA Crampton and LM Tolman with the enviable task of determining what actually defines whiskey as whiskey. Published in 1907, the Crampton and Tolman Paper serves as a blueprint for reverse engineering whiskey styles of the late 19th and early 20th centuries.

Todd Leopold at work in the distillery

“They looked at what the grist bills were,” said Leopold. “They looked at what kind of stills they used. They looked at the entry proof. They looked at, ‘Was the warehouse heated?’ They looked at all of these different contributing things.”

In 31 distilleries studied by Crampton and Tolman, every plant that made Bourbon used a column still. And facilities that made rye used a three-chamber still, sometimes called a charge still. Even Hiram Walker and Company, the largest distiller on the continent at the time, used both types of stills. Leopold asked why companies that already had column stills – the most efficient way of making whiskey – would use the much more labor-intensive charge still? And the answer is flavor.

“Every single one of the rye producers, except for one, used the three-chamber still,” said Leopold. “So, this wasn’t just some gimmick or contraption, it was actually the tool of choice.” 

From that different style of still came a different style of whiskey that, in the day, was referred to as heavy bodied. More importantly, the type of still used to make rye whiskey seemed to have gone extinct. But the still is not the only factor influencing the flavor in Leopold’s whiskey, and on the way to bringing back this style of distillation, he reverse engineered other common practices that had gone out of style in making whiskey. 

“Everything we do here is with intent,” said Leopold. “We don’t just make stuff and throw it against the wall and hope people like it.”

Flavor begins in the ground, with the grain that Leopold contracts local farmers to grow: barley and Abruzzi rye, which is the strain of rye that was most commonly grown in Maryland in the late 19th century. The mash bill for the Three Chamber Whiskey is 80 per cent Abruzzi rye and 20 per cent house-malted barley. 

Abruzzi rye is lower in starch and higher in flavor-producing compounds than modern commodity rye. The high starch content yields more alcohol but, because starch is essentially flavorless, it delivers less flavor. 

“I have to add 30 per cent more of the Abruzzi rye into my mash tun to get that 5%-alcohol beer that I’m going to distill into whiskey,” said Leopold. “Right out of the gate, I am making a whiskey that has more rye flavor because I’m putting more rye in for the same amount of alcohol. So that’s a big, big departure when we’re talking about the differences between the way whiskey was back then [and] the way it is now.”

A solids from a secondary fermentation forms cap over an open fermentation tank at Leopold Bros. The secondary fermentation creates acetic acid, which imparts fruity esters on resultant whiskey. Photo © Andrew Faulkner

Two particular flavor-producing compounds in the Abruzzi that Leopold focuses on are linalool and ferulic acid. Higher concentration of linalool adds floral notes of lavender, elderflower, or chamomile. The right yeast converts ferulic acid, which is abundant in both rye and wheat, into 4-vinyl guaiacol, a compound which gives a clove-like spice note to hefeweizen beer and rye whiskey. 

Leopold studied brewing at Chicago’s Siebel Institute and Doemens Academy in Germany, before working at several German breweries. In fact, when Leopold Bros was founded in 1999, it was a brewpub in Ann Arbor, Michigan. Leopold began distilling in 2001, after attending the Alltech Brewing and Distilling Academy in Lexington, Kentucky. In 2008, the brothers moved the company to Colorado, where they had grown up.

Temperature and yield are two of the many controls distillers have for altering flavor. Cold fermentations and low-yield washes are consistent with whiskey production methods in the Crampton and Tolman paper. Fermenting at a lower temperature delivers flavor precursors that Leopold finds desirable while reducing stress on the yeast.

“When you stress yeast out, you get fusel alcohols,” said Leopold. “You get ethyl acetate, and it totally changes the nature of the Bourbon or rye.” Those are compounds often producing heat in whiskey. Leopold said laboratory tests indicate Three Chamber Rye Whiskey has approximately half the fusels in a typical rye whiskey.

“What we do is: we pitch our yeast. We ferment very, very cold. We ferment in the 60s and we allow for a secondary bacterial fermentation to occur,” said Leopold. “Our open fermenters are set out next to windows. We’ve got peach trees, crab apple trees, lavender, and roses outside the window.”

Todd Leopold

Leopold Bros designed the building so that air would be pulled in the windows and circulate over the fermentation tanks. The secondary fermentation creates a thick, brittle crust on top of the wash, and more importantly, compounds that will be the building blocks for flavor.

Leopold is inviting the right microbes – wild yeast, lactobacillus, certain bacteria – to colonize and create an ambient population, which will in turn produce a “micro-terroir” (if you will) inside the distillery. These wild yeasts, along with lactobacillus from the house-malted barley, produce acetic acid, which is commonly associated with vinegar and sour beers. Acetic acid is a desired compound for Leopold because over time in the barrel it combines with wood extracts to make an ester called octyl acetate. 

“All of this stuff we’re doing is trying to get a house note – and we’ve been here about five or six years,” said Leopold. “You’re going to taste the octyl acetate in our whiskey… It actually tastes like orange marmalade. So, we have a house note in all of our whiskey. Yeah, it’s delicious.”

So, we’ve got the turntable, and the needle is on the vinyl. Now let’s talk about the amplifier. Since stills concentrate and “amplify” flavor, it is only appropriate. No charge stills were known to exist. The still of choice for rye whiskey from the heyday of rye whiskey was thought extinct. 

Leopold began to piece together plans for a three-chamber still from the scant few drawings, diagrams and descriptions he could find. After resettling in Colorado, he created Leopold Bros Maryland Style Rye Whiskey as a homage to an old production method. When it was released in 2011, there were no craft distillers in Maryland making rye. Ironically at the time, most Maryland farmers grew rye in rotation as a cover crop but it was mostly plowed under or burned off. The grain cost more to harvest and bring to market than it could be sold for. Leopold named his rye Maryland-style to give consumers a breaking point from other ryes, which had different expected flavor profiles. He called it more fruity and less spicy, a descriptor that still sticks with the category. 

The chamber still was one of many creative projects sitting on the back burner in 2013, when a story about charge stills by cocktail historian David Wondrich sparked a number of posts on Chuck Cowdery’s blog, Cowdery’s followers added research and more research about this “extinct” still, creating a lot of chatter. The Leopold brothers knew they had to act on their plan. They quickly commissioned Louisville-based Vendome Copper & Brass Works to build a working model, standing 20 ft high and 5 ft in diameter.

Leopold fired up the three-chamber still in 2015; it was thought to be the only one of its kind, though there was one gathering dust in a Barbados distillery. The other was built by a company named Vulcan in the late 1800s and moved to the Caribbean after Prohibition. 

The Leopold brothers knew they had to act on their plan

Both stills operate very differently from other kinds. This is not the kind of still that an operator can monitor or control from an iPad, from the office down the hallway, or the café down the block. It needs to be babysat. This still is analog.

“I absolutely love running it. It’s so much fun,” said Leopold. “It’s very visceral, and who runs this still matters. You know, the amount of steam that you’re adding is a manual thing, based upon what I’m seeing and what I’m touching… It’s an awful lot of fun for me that I’m 25 years into my career now and I get to run a still.”

Distiller’s beer, or wash, enters into a holding tank at the top of the still, which serves to both preheat the next batch and the pre-condenser, creating reflux. Distillation occurs in the three chambers, which are stacked below the preheater/pre-condenser. The vapors collected into new make spirit steam from the top chamber, spiralling in a worm-coil pipe through the preheater.

The freshest charge is at the top chamber, which is the coolest of the three, and the most-spent wash is in the bottom, which is also the hottest chamber, almost to boiling. When the wash in the top chamber starts delivering tails, the batches are changed. The bottom chamber is emptied and each successive chamber is drained into the one below it, until the top chamber receives the preheated wash and the preheater/pre-condenser is charged with fresh distiller’s beer. A 400-gallon charge spends 20-30 minutes in each chamber, so the total cook time from entry until it exits as pig feed is about 90 minutes, versus 90 seconds in a column still.

In column stills and pot stills, on which almost all American whiskey is made, the spirit travels two ways. Lighter, more volatile vapors pass up through the plates, while heavier compounds condense and drip down, or reflux. In the chamber still, vapors travel only one way, bubbling up into the next chamber through inverted, J-shaped pipes. Liquids do not reflux down. Since the liquid in the bottom chamber is spent of lighter compounds, the majority of what gets pushed up is heavier alcohols. Working like a perfume still, it supercharges wash in the top chamber with heavy alcohols and oils. This results in new make that is rich in viscous congeners. 

“The whole still is designed to extract oils, and those oils are going to completely change the mouthfeel and the finish,” Leopold said.

The charge still produces about four barrels of whiskey a day, which Leopold lays down at 100 proof, common practice 123 years ago. 

A lower barrel-entry proof “is going to change the whiskey, full stop. For good, for bad: That’s a matter of opinion,” said Leopold. “Obviously, you can make world-class whiskey at that higher proof. But without question it is going to make different whiskey.”

The strong flavors were difficult to decipher during the first two years in barrel. Leopold described the first year as a train wreck. “The aroma just really jumps out of the glass. And, boy, is there a lot going on,” said Leopold. “The third year [was] ‘Oh, boy! We’re really starting to get somewhere.’ And then the fourth year, it was very much a ‘Hooray!’”

Leopold Bros store the #4 char barrels of whiskey, dunnage-style, in an earthen floor warehouse. Drip irrigation, for the landscaping around the perimeter of the building, adds 20-25 per cent relative humidity inside of the warehouse. Leopold said the proof inside the barrel remains exactly the same throughout maturation, allowing the distillery to bottle in bond, at cask strength, without adjusting ABV. 

Three Chamber Rye Whiskey joins approximately 20 spirits in Leopold Bros’ ever-changing portfolio. The Maryland Style Rye Whiskey, which has a different grain bill than the Three Chamber, is temporarily off market. With its proof being bumped up from 86 to 100 and a little more aging, the Maryland Style will return later this year as a bottled-in-bond whiskey.

While we can assemble a vintage stereo hi-fi the way it was in the 1960s and hear “Surrealistic Pillow” as it was meant to be heard, unfortunately we can’t say the same for the rye whiskey of its heyday. Though pre-Prohibition bottles of rye whiskey surface for auction occasionally, there is little known about how these were stored, if the corks went bad, how the flavors may have migrated over a century, or even if they are counterfeit. Nobody alive really knows what rye whiskey tasted like 123 years ago. Leopold Bros Three Chamber Rye Whiskey brings us one step closer to that experience. 

Tasting Note

Leopold Bros.
Three Chamber Rye Whiskey

The nose is big, complex and constantly evolving, with impressions of chocolate and orange that morph through honey, leather, vanilla and hazelnut. Soft on entry, this thick, viscous whiskey expands on the palate with flavors of cocoa powder, toasted nuts, citrus and hay, finishing long, lingering and warm with a faint piney note. It leaves the impression of a whiskey that is more mature than its five years would indicate.

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