How to Build a Better Bourbon: The Science Behind Buffalo Trace and the Lessons of the Single Oak Project

What better industry could you hope to work in today than the bourbon business? America’s official spirit has never been in better shape. U.S. bourbon sales have risen from 118 million liters in 2000 to 174 million liters last year, and bourbon is increasingly beloved on the global stage. Plus: Free bourbon.

Across Kentucky, quite a few distilleries are taking full advantage of the boom times, doing away with “age statements” on bottles that promise the whiskey inside is, say, “8 years old.” This lets them squeeze out a little more hooch by releasing a younger and younger spirit. As long as the customers don’t revolt, anyway.

So far they haven’t. Prices are going up. Sales show no signs of stopping.

MarkBrownIt’s in this comfortable position that one curious man is finding himself increasingly in the spotlight. Mark Brown is the CEO of the Sazerac Company, a mammoth distilling operation that owns 250-some brands, all the way down to bottom-shelf rotgut like Kentucky Tavern and Crown Russe (slogan: “Finest Vodka Made”). It’s junk that pays the bills for Brown’s passion: Buffalo Trace, a beloved, high-end whiskey operation that produces some of the most noteworthy brands in the bourbon business, including the now feverishly demanded Pappy van Winkle.

Unlike most distillery bosses, Brown isn’t a seventh-generation southerner with a century of bourbon in his blood. He’s not even from America at all. Brown was born in 1957 in a tiny town south of London. After a stint behind the bar at his parents’ pub, he moved here in the ‘70s and worked his way up to the top of the 165-year-old Sazerac. He became Sazerac’s CEO in 1997 and a U.S. citizen in 2006.

The lanky, bespectacled, and wildly energetic CEO now oversees an empire of filled whiskey barrels patiently aging in Buffalo Trace’s many rickhouses in Frankfort, Kentucky (and wherever else it has been able to grab some land). Only four years ago, the company had an aging capacity of 350,000 barrels. Now it has space for nearly twice that – and growing – which has Buffalo Trace buying up land and building new, 50,000-barrel warehouses at a rate of one every five months.

harlan_wheatleyBrown should be coasting, but he’s using Buffalo Trace’s growing coffers not to pad his pockets but to launch one of the industry’s most ambitious scientific investigations into how whiskey should be made. About two years ago, Buffalo Trace formally opened Warehouse X, a tiny brick building with four climate-controlled chambers that the company is using to age whiskey in an environment where every imaginable variable is under the company’s control. Temperature, air flow, humidity, air pressure… everything is monitored by computer and controlled by Buffalo Trace’s master distiller, Harlan Wheatley, the man who convinced Brown to invest over a million dollars into what amounts to an insulated brick shack housing a grand science experiment. Even Brown seems like he’s still talking himself into it, invariably wringing his hands and visibly clenching his teeth when the cost of all this work mentioned (which is often). But he clearly has the bug, confessing to “a nagging doubt that if you aren’t continually improving, you risk someone catching up to you. You can’t rest on your laurels.”

The first experiment being undertaken here is an inquiry into whether light impacts the way whiskey ages in the barrel. Two of the Warehouse X chambers are in 24-hour darkness. One offers full sunlight. One is shaded to 50 percent brightness. (Control barrels sit in the “breezeway” and essentially mimic sitting outside.) It sounds silly. Can a little light shining on an opaque barrel seriously have an impact on the whiskey inside? Just eight months in, Wheatley says that differences between the chambers have already begun show up in the whiskeys – both the changing alcohol level inside and how the spirits taste. The light experiment will run for a total of two years. The results will impact the size of the windows Buffalo Trace builds into its future warehouses.

And that’s just step one. Brown and Wheatley have 20 years’ worth of experiments lined up for the space so far, designed to answer questions like whether a longer fermentation makes for better whiskey years down the road. Or whether staves cut from very old trees make for better barrels (and better bourbon). “I believe the perfect bourbon has not yet been made,” Brown says flatly.

One Bourbon to Rule Them All?

Scientific inquiry isn’t a new idea at Buffalo Trace. An even bigger experiment got its start over a decade ago in the form of the company’s Single Oak Project. At the time, the duo identified seven major variables that might impact how finished bourbon turns out. These range from whether the whiskey uses wheat or rye as a flavoring grain, whether newly-distilled white dog goes into the barrel at 105 or 125 proof, and even whether the wood used to make the barrel was crafted from the bottom half of a tree or the top half of a tree. Buffalo Trace laid down 192 barrels, each one unique, and it has been releasing the finished product to the public over the last four years.

Consumers were invited to weigh in on each bottle’s quality via a website. Over the years, Buffalo Trace amassed more than 5,000 consumer reviews, along with professional critics’ ratings. Last June, the company crunched the numbers – the most delightful big data project ever – and took the five highest-rated whiskeys (excluding bottles that didn’t get enough votes to be statistically valid) through a competitive tasting. A panel of 11 whiskey pros (including this writer) were almost unanimous on the winner. Barrel #80 will be recreated precisely to that barrel’s unique production specifications, then branded as it becomes part of Buffalo Trace’s permanent lineup. It will be ready for release in 2023.

In the meantime, Brown will have to occupy himself with his distillery’s continued, breakneck expansion, plus the mountain of data he’s collected about the SOP. I’ve done some of the work for him in the sections that follow, but Brown is already looking ahead at multivariable analysis of the data, how significant randomness is in an experiment like this, and the daunting concern over whether barrel #80 was a fluke. “I have to forecast eight years’ worth of sales of a new whiskey brand before one bottle is released. How much should I make in year one? 10,000 cases? 20,000 cases?” he asks, and not quite rhetorically.

Such questions don’t have easy answers, but Brown at least has plenty of lubricant to help grease the wheels of inquiry. 25 million gallons of it, actually, all sleeping quietly in his backyard.

What Difference Can (Half) a Tree Make?

Ready to dig into the data of how various production factors impacted consumer opinions about the finished whiskey eight years later? Get ready for some serious number-crunching…

1

Average ratings weren’t much impacted by tree cut – whether a barrel was made from the top of a tree or the bottom of the tree — but its impact can be seen at the edges of the chart. Good whiskeys were improved by being aged in barrels made from the bottom of the tree, while otherwise lesser whiskeys got worse. Brown hypothesizes that nutrients are more concentrated in the lower parts of trunks and thus have a bigger impact on the whiskey, for better or worse.

2

On the whole, the grain of the barrel wood had no real impact on the average score, but the trendline shows some interesting results for tight-grained barrels. Lower-scoring whiskeys saw a significant improvement from the tight wood grain, while higher-scoring whiskeys saw their ratings dampened.

The Best Little Warehouse in Kentucky

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Warehouse design is a hotly debated topic. Newer designs favor buildings largely made of concrete, which have better fire and spill containment features, but older wooden rickhouses – breezier and more susceptible to temperature swings – are still commonly used. While a few top barrels were aged in concrete warehouses (including the winner), by and large, the wooden rickhouses turned out better whiskeys – with an average 1.7% improvement in tasters’ scores. This was the largest single factor affecting average ratings in the entire experiment.

4

But it turns out even identical warehouses can turn out different spirits. Warehouses M and N are constructed identically, face the same direction, and are situated about 50 feet from each other. But whiskey ages differently in these two environments. After four years, barrels in Warehouse N average 127.9 proof, while those in Warehouse M hit just 124.8 proof. And this spread gets wider with each passing year. The company has yet to explain why this is happening. (This wasn’t a factor in the Single Oak Project, as all the barrels were aged in the same warehouse, but it remains a key issue when you’re dealing with tens of thousands of barrels that, by necessity, have to age in somewhat different places.)

5

It’s commonly said that higher floors of any warehouse – no matter the design – age whiskey faster than lower floors, thanks to those blazing hot Kentucky summers and the fact that heat rises. Most cult whiskeys, like George T. Stagg, are high-alcohol beasts that can spend over a decade at the tops of these warehouses. But it turns out this isn’t always a linear function. In its nine-floor Warehouse I, Buffalo Trace found that the highest rate of proof increase took place on the 6th floor, followed by the 4th. The company posits that increased air flow on those floors is the reason for the discrepancy. Floor number was not varied in the Single Oak Project. (The prior two graphics are courtesy of Buffalo Trace.)

What’s in a Grain?

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Bourbon is made primarily from corn, but rye and wheat are the two most common “flavoring grains,” used to give bourbon a unique personality. Rye is increasingly popular in the market, but some of the most popular bourbons, including Pappy van Winkle, are wheated. While the top whiskey in the Single Oak Project was made with rye, the trendline shows a surprising, general preference for wheat among consumers.

More Than a Sum of Its Parts

Now here’s an interesting conundrum. We know, for each of the seven categories tested, what the average rating for the various bourbons made using that specific production method was. For each variable, one factor outscored the other(s). For example, we know that wheated bourbons outscored rye bourbons by 0.67%. We know that 105 entry proof bourbons outscored 125 entry proof bourbons by 0.46%. In theory, we can take all of those aggregated, winning attributes and make a theoretically perfect bourbon, which would look like this (the level of improvement over the alternative is in parenthesis for each favor):

  • from a wheated recipe (0.67% higher rating)
  • aged on wooden ricks (1.67% higher rating)
  • stored in a barrel from the bottom of the tree (0.13% higher rating)
  • the barrel staves should have 12 months of seasoning (1.04% higher rating)
  • the wood should have average grain (0.03% higher rating vs. both tight and coarse grain)
  • the barrel should be a #4 char (0.14% higher rating)
  • 105 entry proof (0.46% higher rating)

This exact whiskey was in fact produced in the Single Oak Project: Barrel #124. Winner it was not. Its composite score was a 6.45 out of 10, which was the fourth-worst-rated whiskey in the entire experiment. That’s a key lesson to be drawn from the data: These variables may interact in ways far more complex than a few spreadsheets can describe.

In contrast, here’s what the winning barrel, Barrel #80, looked like:

  • from a rye recipe
  • aged on concrete ricks
  • stored in a barrel from the bottom of the tree
  • the barrel staves had 12 months of seasoning
  • the wood had average grain
  • the barrel had a #4 char
  • 125 entry proof

Of the seven “ideal” variables, Barrel #80 complied with just four of them.

The ultimate lesson from the Single Oak Project may very well be, just like the old moonshiners used to tell us, that whiskeymaking is more art than science after all.

Review: Canadian Club 100% Rye

canadian club 100 rye

I don’t remember the last time we saw something new from Canadian Club (turns out it was 2011), but with absolutely no warning or fanfare the blender has released a new whisky. As the name fairly freely suggests, it’s 100% rye, produced by the rye giants at Alberta Distillers Ltd.

As a reminder, “rye” whiskey need only be 51% rye (the remainder being comprised of corn and other grains), and rye as we know it tends to be all over the map, mashbill-wise. This bottling is, of course, unadulterated rye, and while there’s no age information offered, we do know it is blended from three different barrel types: new white oak, once-used bourbon barrels, and refill Canadian whisky barrels.

Despite the “100%” moniker, this is an entry-level rye. The nose kicks things off with fairly heavy granary notes, with some brown butter, heavy-char wood, and some darker floral elements. The aroma comes across as relatively immature, lacking in the spicier elements inherent in a great rye.

The palate shows modest improvement, tempering the grain — still considerable — with butterscotch, caramel corn, and notes of burlap. These notes all fade away quite quickly though, finishing the experience rapidly and cleanly. That grainy focus sticks with you however, though not in an oppressive or unsatisfying way. Rather, it serves as a gentle reminder that no matter what grain or grains you put in the mash, it’s the time in the barrel that really matters.

80 proof.

B / $20 / canadianclub.com

Review: Crown Royal Noble Collection Cornerstone Blend

crown royal cornerstone blend

Crown Royal is embarking on a new collection of whisky releases called the Noble Collection. This will be a series of annual, limited releases (no time horizon has been announced), each designed to “showcase Crown Royal’s team of talented distillers and blenders and named for the whisky brand’s noble roots.” (Crown Royal reminds us that the brand originated as a gift for King George VI when he visited Canada in 1939.)

The first installment of the Noble Collection, Cornerstone Blend, is a blend of three whiskies, and Crown Royal has taken the interesting step of actually telling us a little bit about all three of them: a traditional Canadian rye, a rye made using Crown’s Coffey still, and a “bourbon-style Canadian whisky” that is matured in American oak. There’s no additional data on the three whiskies or their proportion in the blend, but that’s a nice start.

I take that back: It’s even better than that, because Crown Royal sent individual samples of all three of the component whiskies for us to check out as well as a sample of the finished blend. Before we move on to the review of the finished product, let’s take a quick look at the trio on their own to see what ingredients we’re working with. (Note: All three samples are cask strength, while the finished blend was brought down to 40.3% abv.)

The Cornerstone rye (111.4 proof) is quite gorgeous, a spicy, toffee-heavy whisky with a long finish of cloves and toasted wood. The Cornerstone Coffey rye (122.8 proof) has some similar characteristics, but is less polished and has a duller profile on the whole, with a heavy grainy character and some flabbiness on its finish. A lot of the character of the finished product clearly comes from this component, which is the least engaging of the trio. Finally, the Cornerstone “bourbon-style” whisky (136.4 proof) is engaging but is almost overloaded with sweetness, featuring butterscotch, cocoa powder, and ample barrel char.

Putting everything together, it’s a bit less than the sum of its parts. Crown Royal Cornerstone Blend is a bit of an odd whisky, punctuating a heavy barrel char character on the nose with briny notes, camphor, and some green olive notes. Sweetness is elusive at first, but shows its face on the restrained palate, which shows off notes of blonde wood, furniture polish, some raisins, and some rye-driven baking spices, including cloves and ginger. The finish is mild and short, in keeping with the greater experience: On the whole Cornerstone is dialed back, way back, a very model of restraint so effective that it’s difficult to get a proper handle on its essence. It’s not a bad whisky, but it comes across as a bit plain, almost to the point of boredom.

80.6 proof.

B- / $50 / crownroyal.com

Review: Diageo Orphan Barrel Project Rhetoric Bourbon 22 Years Old

rhetoric 22 years old

Diageo’s Orphan Barrel project has an ambitious goal with the Rhetoric brand. First released as a 20 year old in 2014, it was further aged and reissued as a 21 year old last year, and as a 22 year old this month. 23, 24, and 25 year olds will be forthcoming through the remainder of the decade.

We have had the good fortune to taste the new release alongside both the 20 and 21… a practice we hope to keep running over the course of the six whiskey releases (supplies in our stock permitting).

Here’s how Rhetoric 22 (still 86% corn, 8% barley, 6% rye, distilled at Bernheim in the early 1990s) shapes up against its forebears.

At age 22, Rhetoric is showing ample wood — one might say it’s become the primary focus of the bourbon at this point in its life — though the nose backs that up with some aromas of Port wine and a touch of orange peel. On the palate, barrel char and lumberyard hit first, followed by soothing vanilla and toffee notes. Secondary notes run to red fruits, namely raspberries, plus heavy notes of cloves and mint chocolate. This is a quite complex whiskey, with a lengthy finish. There’s ample heat here, which is surprising given that the whiskey is barely 45% abv, but a couple of drops of water help it open up.

Looking back, I like the 21 a bit less now than I did upon last year. It is now showing a bit heavy on winey notes up front, though the lovely brown sugar character that cascades on the lightly woody finish are still working well. The 20 year old is still showing well, with stronger menthol notes and sizable wood character on the finish.

90.4 proof.

A- / $110 / diageo.com

Review: Booker’s Rye “Big Time Batch” 2016

Booker's Rye Bottle + Box Lifestyle Shot

It is easily the most notorious whiskey release of the year, but Booker Noe — otherwise known exclusively for bourbon — couldn’t have predicted such when he decided to lay down some rye barrels in 2003. (Noe died in 2004, but his name has lived on in his namesake bourbon.) Apparently he took the mashbill information on this whiskey — believed to be about 70% rye — with him.

Now, 13 years (and 1 month and 12 days) later — roughly double the time that Booker’s Bourbon spends in cask — Beam Suntory has turned out those barrels and bottled them at cask strength. It is the first and so far only rye whiskey released under the Booker’s name, a very well-aged, one-off release that is turning heads mainly because of one thing: A $300 price tag.

Rye is red hot right now, but this release now has observers wondering whether we’ve hit “Peak Rye.” Even cult-level rye bottlings like WhistlePig’s rare bottlings don’t command that kind of coin. You have to look at the tiny number of Sazerac 18 Year Old bottles out there if you want to find any competition in the price range.

Ah well, let’s see what’s inside these ritzy bottles, shall we?

The nose is intense, one of the richest and most powerful I’ve encountered in an American whiskey in a long time. Huge aromas of toffee, barrel char, and licorice are backed by notes of orange marmalade, ginger, and torched brown sugar. The nose just goes and goes — it’s one of those rare whiskeys that is intensely enjoyable without ever taking a sip.

And yet, sip we must, and said sip is glorious. At 68% alcohol, Booker’s Rye ought to be a blazer, but it’s surprisingly gentle and easily approachable even at full strength. The body is complex and soaked through with notes of molasses-dark caramel, flambeed banana, tons of cloves, and Port wine. While it isn’t required, water doesn’t hurt, coaxing out more up-front sweetness to endure on the finish. All told, it’s a dramatic, powerful, and beautiful whiskey, perfectly aged and well worth sampling should you manage to encounter one of the few bottles that were produced.

Have we arrived at Peak Rye? You better believe it. Does it matter? As long as the whiskey turns out this amazingly: No.

136.2 proof.

A / $300 / bookersbourbon.com

Review: Ol’ Major Bacon Flavored Bourbon

Ol' Major with Bacon

Another whiskey from Branded Spirits… this one with a major (and obvious) spin.

To start with the basics: This is real whiskey flavored with real bacon. The bourbon is an 88% corn mash made by Terressentia, the bacon if from an Oklahoma pork producer. The flavoring and bottling operation takes place in Nashville; this involves taking nitrous aerosolized bacon, injecting it into the bourbon, and then filtering it heavily to remove the solids.

Hands down this is the best bacon-flavored spirit I’ve encountered to date. Slightly meaty, slightly salty, the pure bacon essence grows stronger as it evolves in the glass. On the palate a maple syrup character is prominent, with those classic bacon notes building on the lingering, slightly smoky finish.

Consider me pleasantly surprised. While it sips surprisingly well, it’s definitely made for mixing — try it in an Old Fashioned or a Bloody Mary.

70 proof.

A- / $25 / brandedspiritsusa.com

Review: Michter’s US-1 Barrel Strength Straight Rye 2016

Michter's Barrel Strength Rye

Michter’s is back with its second barrel strength rye, which is a higher-proof rendition of its US-1 Single Barrel Rye. The interesting thing about this rye: It goes into barrel at just 103 proof. 125 entry proof is standard; 105 proof is used sometimes, but 103 is quite on the low side.

Hot on the nose, the whiskey kicks off with a bold grain profile and layers and layers of spice — both the sweet baked goods variety as well as some cayenne. Some nutty and honeycomb notes emerge given time in the glass, along with some oxidized wine aromas.

On the palate, the whiskey pushes its grain base heavily, again backing a heavy cereal character with ample spice. Rather oily, it layers on notes of rhubarb, currants, and some sour cherry, finishing on a surprisingly tart note.

Altogether it’s quite a different whiskey than Michter’s standard-issue US-1 Rye (and a somewhat better one), it doesn’t quite find the balance it needs to really raise the bar. That can be a challenge with rye, particularly relatively young expressions, as this one appears to be, but it’s at least a solid effort through and through that grows on you the more time you spend with it.

Note: These are single barrel releases and proof will reportedly vary between about 110.2 proof and 114.8 proof. As reviewed: Barrel #16D432, 111.8 proof.

B+ / $75 / michters.com