Around the Barrel - Transcript: Ep031 Kevin Smith

 

Kevin Smith: You know, I've heard Jeff Arnett, our Master Distiller, say several times that we don't necessarily make whiskey the way Jack Daniel made it. We make it the way he would wish he could if he had the same knowledge that we do today.

 

Lucas Hendrickson: So many recognizable elements go into making Jack Daniel’s Old No. 7 Tennessee Whiskey unique: custom made barrels, cave springwater, piles of sugar maple charcoal, but there's one thing that sets Jack Daniel’s apart you wouldn't recognize even if you could see it – which you can't without a microscope. 

 

On this episode, we talk with Kevin Smith, chief biologist at the Jack Daniel Distillery, about the vital role yeast plays in creating the amazing character generations of whiskey fans have come to know and love. 

 

He gives us a crash course in the history of these tiny organisms and their importance in creating alcohol, and he gives us a peek at the next phase of the Tennessee Taster Series, a project he hopes continues the spirit of innovation found in and Around the Barrel. 

 

Welcome back to Around the Barrel, the official podcast from the makers of Jack Daniel’s. I'm your host, Lucas Hendrickson. The smallest things often make the biggest difference. That's definitely the case with the role yeast plays in making Jack Daniel’s Old No. 7 Tennessee Whiskey unique. 

 

Kevin Smith – no, not the filmmaker Kevin Smith – is the man tasked with making sure that the single celled organisms crucial to the alcohol production process are happy, healthy and able to perform at peak levels. It's an important component given not only the scale but also the consistency needed to produce one of the world's most popular spirits.

 

Kevin: Hi, I'm Kevin Smith. I'm the Jack Daniel’s distillery technical manager and microbiologist at the Jack Daniel Distillery. My responsibilities are maintaining the production of yeast and lactic bacterial cultures that are used to produce our fine Tennessee whiskey. 

 

I've been with Jack Daniel’s and Brown-Forman since 1995. I really originally started with the corporation, Brown-Forman corporation, in my hometown of Louisville, Kentucky and then transferred here to Lynchburg, Tennessee in 1997. 

 

I live just outside of Lynchburg in a small village called Lois. It's the area where the original Jack Daniel's distillery was before it moved into the heart of Lynchburg. So, that's who I am.

 

Lucas: Kevin Smith, welcome to Around the Barrel. We've talked a lot across this show about the things that make Jack Daniel's unique. 

 

Obviously the place, the water source, the barrels, the charcoal mellowing process, everything, but if you're around the spirits making or the alcohol production worlds at all, people learn very quickly that it's the yeast that really makes spirits, beer, whiskey, whatever, completely unique. 

 

Kevin: Absolutely.

 

Lucas: Tell us a little bit about the process of kind of maintaining that small microbiological entity that gives Jack Daniel’s so much character.

 

Kevin: Sure. Well, you think as the microbiologist that I would be very yeast focused and tell you that the yeast is the most important thing contributing to the whiskey flavor and character. 

 

But, you know, the truth is I recognize that although it provides a unique and distinctive character, it actually kind of – the character of the yeast sits a little bit behind the very important aspects of Tennessee whiskey, charcoal mellowing and our cooperage as well, the barrel maturation. 

 

But to allow that yeast to shine forward and consistently, we practice, you know, some very traditional means of culturing and propagating the yeast culture in the laboratory and then scaling it up on a weekly basis to send out to the distillery for weekly distillery production needs. 

 

You know, it's a pretty fascinating process, at least to me. I'm very focused on making happy, healthy yeast cells, and that begins with giving them all the things that they need to grow and multiply and be healthy and well conditioned in the process. 

 

So, we maintain a media that we make up and transfer the yeast several times a week. I even jokingly call it yeast calisthenics. We transfer the yeast several times a week and so the goal – and that's on an imbalanced cycle, on a one day in a six day cycle. 

 

And so that short cycle trains the yeast to grow up very quickly and then the long cycle trains it to endure in a longer fermentation and continue fermentation until the very end of a six or seven day fermentation.

 

Lucas: Okay. For the abject newcomer who's kind of looking at, you know, the history of spirits making, of alcohol production, what and where – if you can detail that for us or at least give us a hint – where did the discovery of yeast as such an important part of alcohol production come into play? What's the history of yeast as far as creating spirits?

 

Kevin: Well, you know, it goes back I think 9,000 years, the first written and archeological evidence of fermentation. But really the truth is almost for that full 9,000 years plus, it really has been a mystery. 

 

The science of microbiology is pretty modern, I think going back to this gentleman Van Leeuwenhoek, who discovered or created a microscope that could see yeast, and Louis Pasteur, who proved that yeast causes fermentation and bacteria spoils fermentation. That was really just in the last 200 years. So, the science of microbiology is approximately 160 years old. 

 

And I tell people all the time when they come to visit the distillery and we're talking about the yeast, I say and I ask the question, “What else happened around here about 160 years ago?” And that's when Jack Daniel started producing Tennessee whiskey in the holler here.

 

I also note that that isn't necessarily because of the discovery of yeast, because people knew how to do fermentation for many years before that. So, it was really about that time when people were learning the role of yeast and how to better take care of and propagate the yeast to ensure a good and consistent fermentation and a nice unique spirit. 

 

So, that's a little bit about the history of yeast. Of course, we've obviously improved in our methods of maintaining and conditioning the yeast since Jack Daniel's days. 

 

Lucas: Right. 

 

Kevin: I think about the time that Jack Daniel was making whiskey, to start a fermentation, you would just take the yeast, the heel of one fermentation, and transfer it to the next fermenter to continue that process. 

 

And over the years, they would move the control of the yeast to a special room at the distillery called the yeast room. And it had special tanks called yeast tubs that were used to grow the yeast up and then send out to the fermenters. 

 

And then probably around 40 years ago, the control of the yeast was brought into the laboratory so that we could maintain it in a more pure form and also condition it better going out to the distillery for scale out purposes. 

 

So, that's a little bit about the history. Of course there's not a lot of documentation from the early days about the maintenance of the Jack Daniel's proprietary yeast strain. We understand that it goes back and has been maintained in this what we call serial subculturing, or just transferring from one batch to the next since his time. 

 

The documentation on especially the move into the laboratory and the preservation of the strain and the control of the strain has improved over those years.

 

Lucas: Yeah. And is that where the idea of a proprietary yeast comes into play as you've been able to kind of identify and isolate and propagate, you know, future generations of it? That's where proprietariness comes into play?

 

Kevin: Yeah, absolutely. And of course the proprietary – that term just means that we own it and we control it and it is of a particular character that we like to see in our Jack Daniel's whiskey. And so, you know, there is a move in the larger industry away from the use of an implant culture to use commercial yeast strains brought in from commercial use vendors. 

 

And, you know, it's certainly a lot easier. You don't need the technical resources. You don't need to have a microbiologist on staff to be able to run it that way.

 

Lucas: But it helps.

 

Kevin: It does. You can, you know, maintain and control your flavor. And there's many things that we do with our yeast strain building on the calisthenics for yeast to ensure that they produce the character, the flavor, the yield and the consistency that we want.

 

Lucas: Yeah. How much does the idea of Jack Daniel's being made in one place add to that consistency of the yeast? 

 

Because obviously you have local flora and fauna that can help change the, you know, nature of those yeasts as time goes on, but because you are in one place and every drop is made in Lynchburg, how does that add to that consistency as the decades go by?

 

Kevin: Well we certainly can control it over time. You know, one thing I didn't say earlier in terms of the history of the maintenance was we would use what we call a jug yeast to cover periods where we weren't producing. 

 

Maybe shut down once a year in the summer months. When it gets really hot, we would shut down the distillery to clean things out and do major maintenance. And so we would put the yeast culture into a metal jug that had a valve on the top. 

 

So, as the yeast would produce CO2, it would pressurize and go into what I call suspended animation. By refrigerating that, you could get that yeast to endure for many months in that way. 

 

But in that jug yeast, you could develop multiple yeast strains with slightly different character, but they all would go back to Jack Daniel's proprietary yeast strain.

 

So, what we would – what I did in one of my first tasks when I started with Jack Daniel's in 1997 was to go into that jug yeast and isolate many dozens of unique yeast strains with slightly different flavor but then all go back to the original Jack Daniel's strain. 

 

And so we have those stored in our laboratory and we can bring those out and revive those and characterize them. So, you know, an interesting point is we don't necessarily use that diversity of yeast strains to make different flavors and different characteristics in our whiskey. We actually use it to keep our whiskey consistent. 

 

So, other things change at the distillery. Grain quality can change from season to season. And so we can use that diversity of yeast strains to dial in the flavor profile and keep Jack Daniel's extremely consistent and to consumer expectation.

 

Lucas: Yeah. What are you most focused on these days when it comes to whiskey making and the interaction of all of these different processes into what becomes this now kind of wide diversity of products in the Jack Daniel's line?

 

Kevin: Yeah, so you know, I really kinda consider myself a fermentation specialist, and my goal is to of course ensure the flavor and consistency of Jack Daniel's, but I'm very focused on optimizing all the processes related to yeast and fermentation. 

 

And there's a very good reason for that. We have this major challenge in fermentation of having the yeast outcompete any bacteria that comes in the system. And so I tell people it's really an amazing number. With every gram of grain that comes in, there are hundred thousand plus bacteria naturally associated with that grain. 

 

And so our goal is to get the yeast healthy enough that it outcompetes those and control the sanitary conditions, the cleanliness of the plants, so that the yeast does what it needs to do and the bacteria are suppressed. And so that's really a lot of what I focus on a day to day basis.

 

That's important for several reasons. In the end, this is the largest whiskey distillery, American whiskey distillery, in the world, and we produce a lot of whiskey. And so our goal is to take that grain that we receive and to make a good, consistent whiskey. And as much of it as that grain will allow us. 

 

And that's not just a bottom line decision. If we want to get as much alcohol out of each gram of grain as we bring in here, or a pound of grain or bushel, it's important for flavor as well. So, if we completely ferment out the sugars that are in the grains, all that sugar is depleted. You have to remember that after we ferment, we take this beer and run it through a hot distillation process. 

 

And if there are residual sugars in there, those will char and lead to off flavors and aromas in the whiskey. And so by achieving the best fermentations with the best yield, we also get the best and most consistent distillate to come out of there too. So, in a nutshell, that sums up where I focus my daily efforts and activities.

 

Lucas: Gotcha. Now, in this moment where the distillery is also producing, you know, high grain spirits to be then moved over into other companies that are using it to create hand sanitizer and other products, where has your interaction with that process been over the last couple of months?

 

Kevin: Yeah, so that's been actually a lot of fun. You know, very much like the Tennessee Tasters and the different line extensions that we've been doing, every time we change things up a little bit, it creates new challenges that I'm typically involved in. 

 

The high corn high proof ethanol for hand sanitizer to help serve the public during this COVID pandemic – I mean, it's been interesting. 

 

Obviously it's not something that we do typically, but it's allowed me to, you know, exercise some of the knowledge and background that I've had to produce a higher proof spirit and to push our throughput capacities to be able to produce as much as possible. 

 

A lot of technical jargon, but switching over from these other strains, the rye and the malt, to a predominantly corn fermentation means that you have to do some different things with the yeast and the enzymes to break all those starches down to sugars to feed the yeast and to make as much alcohol as you can.

 

We're not so concerned with flavor with the hand sanitizer. And so it opens up some opportunities for us in terms of the conversion and fermentation. And that kind of brings us back to a point about, “What is traditional about Jack Daniel's and the things that we do?”

 

I think, you know, I've heard Jeff Arnett, our Master Distiller, say several times that we don't necessarily make whiskey the way Jack Daniel's made it. We make it the way he would wish he could if he had the same knowledge that we do today. 

 

With that knowledge and new capabilities and new technology come opportunities, but there also come threats to the whiskey space as well. Just because there's a tool available doesn't mean you want to apply it to a very traditional process such as the making of Tennessee whiskey. 

 

Lucas: Right.

 

Kevin: And so I've done a lot of work and given many, many presentations recently to folks coming, visitors to the distillery talking about those traditional processes and defining those. We often hear the term craft distilleries and so on. That's typically associated with size, but we think that Jack Daniel's is the best practitioner in the art and craft of whiskey making. 

 

And that includes the processes of maintaining our own yeast culture, continuing to use our natural malt enzymes to break down the sugars and the starch in those grains and to feed the yeast. It's the continued use of the lactic bacteria soured yeast mash in the process. 

 

So, there are many aspects of it. You know, obviously our goal, our responsibility is to educate consumers on these processes and how Jack Daniel's best maintains and preserves those traditional processes. 

 

Lucas: Right. And the phrase sour mash gets used a lot in the spirits world. 

 

Kevin: It does. Yeah.

 

Lucas: Delineate that for us. What is a sour mash? How do you use it in the process? How do you control such a natural process?

 

Kevin: Yeah so sour mash – the term souring really just refers to lowering the pH of an environment. I mean, not everybody knows what a pH is. It's kind of a simple measure of basic or acidity, but in the case of our sour mash, there are really two aspects of the sour mash process. 

 

The first is, I think, pretty well known to most folks. And that is how, the process by which, we take some of the mash, the thin stillage that comes off the bottom of the distillation columns, and then we recycle that back into our mash cookers. 

 

There's several reasons we do that. There are some organic acids in there that lower the pH of the mash that helps the malt enzymes work better in the next cycle. There's lots of dead yeast in that thin stillage as well, that backset, and that feeds the yeast in the next cycle as well.

 

I think the general public understands and knows about that aspect of sour mashing, but what they typically don't know much about is what I call the second aspect of sour mashing. And that's the use of lactic bacteria in the souring of our special yeast mash. 

 

So, we make a separate yeast mash to grow and propagate and feed the yeast, but before we use it to grow the yeast, we actually intentionally inoculate it with lactic bacteria. So, these are similar bacteria to that which is used to make yogurt, and it produces lots of lactic acid that lowers the pH of that environment and also creates some flavor to the whiskey as well. 

 

So, if you do all this right, you create optimal environmental conditions for the yeast to grow and to perform very well in the fermentor. 

 

Lucas: Right. You mentioned just a little bit ago the Tennessee Tasters series. And you were involved heavily in the creation of what's called Barrel Reunion #2, which was the second of the Barrel Reunion series, this one working with an area craft beer producer that used Jack Daniel's barrels to age an oatmeal stout. 

 

And then those barrels went back to Lynchburg to finish aging the special version of Old No. 7 done in reunited barrels. Tell us a little bit about your involvement in that and kind of detail for us, for those who haven't had it because it's just available in Tennessee, what the flavor profile on that particular whiskey is.

 

Kevin: Yeah. So, as you would expect with the the reunion, the beer Barrel Reunion, especially coming out of a oatmeal stout barrel – you know, that's a bold style of beer and it's gonna have a lot of heavy malt, almost kind of molasses-y type flavors that would be in that beer. 

 

And so we knew that it would leave lots of residual flavors and again, bold, strong flavors in the barrel. And we felt like that was necessary to compliment the bold flavor characteristics of Jack Daniel's Tennessee whiskey as well. 

 

And so the goal was to use this oatmeal stout barrel. You know, I think there is a lot of enthusiasm lately for these finish aging processes, especially using wine barrels. A lot of – you've seen that across the broader whiskey industry, use of wine finishes. 

 

And not many people are doing the beer barrel finishing and so we thought that was an opportunity to create something unique. Personally, I do a lot of home brewing and so, you know, that's always kind of close to my heart as well. 

 

So, I was bugging Jeff Arnett endlessly about the idea of doing a beer barrel finish before. And of course the relationship with the local brewery that we partnered with or collaborated with on this – there's some local connections to our management as well. 

 

And so it made it a natural partner, and they produce a good quality beer for sure. And in fact, the product that came out of that brewery – they call it the Baroness, the 2020 release I think. It was just a beautiful brew. 

 

Really nice coming out of the Jack Daniel's barrels as well. So, bringing those barrels back to Jack Daniel's then to finish aging there in those barrels was a great opportunity.

 

And, you know, the challenge in finish aging is when you already have a 4 year plus mature whiskey product going into those barrels, the question is, “How much flavor can and will it pick up?” 

 

And so that was a bit of a mystery, you know, and we were very pleased. They weren't dominating notes. They were just kind of balanced nice. You know, you could pick it out and get that essence of the oatmeal stout that resided in the barrels for a few months prior to our finish aging. 

 

Lucas: Yeah. Well, and I have not had Barrel Reunion #2, but I did have the #1, which was with a local winery. And so those red wine notes certainly carried through onto that whiskey. I'm fascinated to try, hopefully very soon, the more multi kind of things that will come off of a traditional oatmeal stout. 

 

Well, Kevin, thank you for your time. Thanks for your work with one of the world's most favorite Tennessee whiskey brands, and we look forward to seeing the other things that are coming down the pike from you there in Lynchburg.

 

Kevin: Well, I appreciate you inviting me to speak with you today and look forward to more conversations in the future. Take care.

 

Lucas: Absolutely. Thanks for joining us Around the Barrel.

 

Around the Barrel is the official podcast of the Jack Daniel Distillery. Follow the podcast on the web at jackdaniels.com/podcast. 

 

If you like what you hear, please subscribe, rate and review at Apple Podcasts, Google Podcasts, Spotify, or wherever you gather your on-demand audio. Always remember, with great podcasts and great whiskey, please enjoy responsibly. Join us next time for more conversations Around the Barrel.

 

Your friends at Jack Daniel’s remind you to drink responsibly. Jack Daniel’s and Old No. 7 are registered trademarks, Copyright 2020 Jack Daniel’s. Tennessee whiskey, 40% alcohol by volume, 80 proof, distilled and bottled by Jack Daniel Distillery, Lynchburg, Tennessee. Around the Barrel is intended for listeners 21 years of age and older.