Laboratory Verdict: Bourbon vs. Single Malt!


Very exciting times! We have added the iStill Laboratory Services to our already impressive portfolio of products and services. Why? To help empower craft distillers all around the world. How? By providing them with scientific feedback on the drinks they produce. Feedback and advise on how to improve product quality. More and better information helps make better decisions. A better informed craft distiller is an empowered distiller.

Today we present the laboratory findings of a comparison of a Bourbon (Jim Beam) to a Scottish single malt whisky (MacAllan 12 year old). Not your cup of tea? We disagree. The analysis and advise we share underneath is as applicable to your whisky as it is to Jim Beam’s and MacAllan’s. If you want to beat them, all you need is a steeper learning curve. So stay with us … and stay focused … and learn. It will be worth your time.

What are we looking for? What do we expect to find? Well, in a very concise way, the very first thing we want to find out is how a regular Bourbon and single malt compare. But on a deeper level, much more is at stake. What? Well, how about Odin’s Holy Trinity of Distillation? What does this theory say about Bourbon and single malt whisky? And does the model survive scientific and laboratory scrutiny?

So, first, let’s dive into the Holy Trinity of Distillation a bit. Some understanding of how the model works is needed. Secondly, if we apply Odin’s theory, how do we expect Jim Beam and MacAllan to perform? We need to find out what the model predicts. Thirdly, we’ll present the laboratorium results. Let’s confront the lab results of the Bourbon and the single malt, and evaluate if the Holy Trinity of Distillation’s predictions were adequate.

Jim Beam Bourbon …

Odin’s Holy Trinity of Distillation

A summary. Less heads and tails smearing results in a lighter product, that highlights the flavors associated with the hearts cut. The flavors that are associated with the hearts cut are the base substrate. In a rum it is where you taste the molasses. In a whisky or Bourbon it is where you taste the grains the product is made from. The flavors hit you in the middle of your mouth. Above the tongue. From seconds 2 till 6 or 7 after taking a sip, wetting your entire mouth with it, and then swallowing the drink. Longer fermentation times and on the grain fermentation and distillation add to a more flavorful hearts section,

The heads smearing can be tasted in the front of ones mouth. Lips, point of tongue, and gum. The heads-associated flavors are fruity in nature and can be experienced in the very first second after taking a sip, wetting your entire mouth with it, and then swallowing it. More heads smearing leads to more fruity flavors in a drink. Less heads smearing, via a bigger heads cut, results in lower front of mouth flavor intensity.

The tails smearing is tasted at the back of your mouth and gradually transitions towards your throat. The tails-associated flavors hit you from seconds 7 till 15 or 20 or even 25. More tails smearing results in a higher and longer lasting back-end flavor.

As 30% of flavor associates with heads and 50% with tails, heads and tails smearing are tremendously important for a drink. More smearing equals more flavor, but also means more aging is needed to mellow all those flavors out.

How a student of the iStill University put it …

Applying Odin’s theory on Bourbon and single malt

A single malt whisky is a three-dimensional product, that has a front, a middle, and a back-end. As the MacAllan has seen a much longer maturation time than the Jim Beam, we expect the whisky to have more heads and tails smearing. The bigger amount of smearing allows the MacAllan to take advantage of 12 years of barrel aging. More flavor equals more time to develop those flavors into something coherent and enjoyable.

Bourbon, in general, is a two-dimensional drink. It has a front and a middle, but not much (if any at all) of a back-end. This is the result of the applied distillation technology, that uses bubble-cap trays in the (continuous) columns. Bubble-cap trays are invented to effectively prevent tails smearing in fruit brandies. It is an 1870 innovation that gained wide traction in American whiskey distillation, because it allows for multiple distillation cycles to be performed in one go. The gained efficiency comes at the loss of the third dimension, to the extend that this absence now is an inherent characteristic of almost all Bourbons.

So, we expect the Bourbon to be relatively fruitier, as the front-end flavors make up more of the total flavor profile. Heads smearing attributes 30% of flavor, hearts just 20%, and tails as much as 50%. An expected absence of tails makes the Bourbon the lighter, sweeter, and fruitier product. The MacAllan is made on a traditional potstill. An old technology that is great at smearing heads and tails into the hearts cut. So, again, we expect the MacAllan to have a bigger first and third dimension than the Jim Beam.

But how about hearts? Hearts flavors contribute about 20% to the overall flavor profile, but who will win here? We expect the Jim Beam to outperform the MacAllan. Why? Because Jim Beam ferments on the grain and does the first distillation run also on the grain. More substrate contact during fermentation and distillation results in a tastier, fuller-bodied middle-flavor profile. MacAllan ferments and distills off the grain, so Odin’s Holy Trinity of Distillation predicts a lower flavor-count for the Scottish whisky’s middle.

MacAllan 12 year old single malt whisky …

Laboratorium results

As predicted by the model, the MacAllan has a more flavorful first dimension. Jim Beam hits the market after four years of barrel maturation. They make a tighter hearts cut with less heads smearing, simply because there isn’t enough time for a bigger heads smearing to mellow out. The MacAllan hits the market after over a decade. There is much more time for the bigger amount of heads smearing to mellow out over time. Put differently: MacAllan takes advantage of its prolonged maturation time via the incorporation of more heads, resulting in a bigger overall flavor profile, at least at the front. Jim Beam applies a similar flavor maximization strategy: given the limited amount of maturation time of four instead of 12 years, they still achieve an impressive result of about 60% of front-end, fruity flavors of the MacAllan.

As predicted by the Holy Trinity of Distillation, the Jim Beam has more substrate-related flavors. The fact that Jim Beam ferments and distills on the grain results in a 15% more flavorful second dimension than MacAllan has to offer. MacAllan lags behind on substrate flavors, because of the off the grain and short fermentation and distillation protocols.

Wow! The Bourbon basically has no back-end flavors. It is a two-dimensional product indeed. The MacAllan has a back-end and therefore a third flavor dimension. The outcomes depicted above are exactly as predicted by the Holy Trinity of Distillation.

Overall, we see that the front-end, sweet, and fruity flavors are more important in the overall flavor profile of the Jim Beam Bourbon. At the same time, we can learn that this generic Bourbon characteristic is more the result of the absence of those dominant back-end flavors than that it stems from a lot of heads smearing.

Advise to Jim Beam and MacAllan

What advise could we give to Jim Beam and MacAllan? In order to improve their whiskies? Not part of the lab results that we presented above, but the MacAllan is a fully matured product. Longer aging does not add anything. As MacAllan bases all of their whiskies on one and the same New Make, we expect that older varieties, like their 15, 20 and 25 year old products, primarily differ via specific cask finishes. The aging itself, above 12 years, seems to be more of a marketing or financial decision than that it is the result of the base drink needing further aging. Again, the spirit itself does not need more aging. Put differently: longer aging does not add anything, but might risk older MacAllan whiskies to loose their front-end due to oxidation.

Could we improve on the MacAllan? Yes we could. And – even though it is never going to happen – so could MacAllan. Where they can improve? Well, the middle of mouth flavors lack body. If MacAllan was an iStill customer, and if they weren’t all caught up in tradition, but open to innovation, we’d advise them to consider on the grain fermentation and distillation. It would put the flavor intensity of their second dimension above Jim Beam, and would bring grain flavors up, thus creating a better balance between the impressive front and the sorta adequate back-end.

Since Scottish single malt is usually fermented and distilled off the grain, there is another solution MacAllan could apply in order to strengthen the weak second dimension while staying true to tradition. MacAllen could return to a 5-day fermentation schedule, instead of the 3-day they have been using for some time. The longer fermentation would probably push the substrate flavors to about 2,000. Of course, it would come at the cost of an overall production output loss of around 40%. As single malts keep on being highly sought after, we do not see that happen any time soon. But be aware: this does open up a window of opportunity for craft distillers that now can quite easily outcompete Big Alcohol single malt production on flavor!

For the rest, we’d advise MacAllan to differentiate their New Makes and allow for more tails smearing in those New Makes that will become their 15, 20 and 25 year old products. More tails smearing will create a more interesting flavor profile that better distinguishes the more expensive and older whiskies from their 12 year old offering. Even the 12 year old might actually benefit from a little bit of additional tails smearing …

The Jim Beam that we tested was well-matured but not fully-matured. Our laboratory estimates that an additional 3 to 6 months would create a slightly smoother taste experience. We’d advise Jim Beam, if they were our customer, to take advantage of the little bit of additional, and thus far unlocked, potential of its Bourbon whiskey by giving it a few more months of rest. But on the other hand, we understand that commercially it is probably not worth it, to wait longer or to even have the labels changed to stating that they now age for 4 1/2 years instead of just 4.

Jim Beam’s market entry delivers where a Bourbon needs to deliver: in the first and second flavor dimensions. We expect their older varieties, like the Jim Beam Signature Craft, which is aged for 12 years, to contain a little more heads and even some additional tails smearing, but haven’t tested that yet. More heads and tails smearing would easily stand up to the robust middle flavors, that Jim Beam already delivers on, and make for a more interesting product, with a longer lasting taste sensation.

Some conclusions for you, the craft distiller

Since you, the readers of this iStill Blog post, probably aren’t the owners of, or distillers at, Jim Beam or MacAllan, what is your take-away? How does this information help you? Well, first of all, you now know scientifically what distinguishes a Bourbon from a Scottish single malt whisky. Secondly, we challenge you to buy a few bottles and start training your taste buds according to Odin’s model. Compare the Jim Beam to the MacAllan yourself, and taste the science we have presented here first hand. After that? Maybe buy a Pappy van Winkle and see how you’d score that on each of the three dimensions.

But there is more. All of you that studied at the iStill University now know that the models we trained you in are more than an amazing toolkit for the craft distiller to work with. Our models and theories are the only toolkit for the craft distiller to work with, since they are now proven scientifically. And that is not an opinion, but a fact.

What this means to you and to the craft distilling industry at large? That we have taken the guessing out of distilling. Finally and definitely and overwhelmingly so! Put slightly differently, it means the following: if you want to become a craft distiller, your future starts with taking the courses the iStill University offers. Interested? You should be. Please reach out to for more information. Why? If that is still a question on your mind, let’s summarize …

iStill – and nobody else! – trains you so that you can make better products. And not in the sense of “I think this is better” or “I actually enjoy this drink”, but with scientific proof that factually confirms that it is better and why it is better. Not an opinion. Not science fiction. Simply science fact.

iStill – and nobody else! – helps you design spirits that are better than anything other companies or consultants can deliver. That is no longer an opinion, but now a scientific fact. We are the only ones to apply science to improve your spirits in a manner that is objectively measurable and verifiable.

iStill technology – and nobody else’s! – makes the best spirits. That is not just an opinion, but now a scientifically proven fact.

Hold on … what? Wasn’t this iStill Blog post about scientifically and chemically comparing and evaluating a Bourbon and a single malt whisky? Yes, it was. But hold on to your seats as well as your pants: we also tested whisky made on an iStill. We’ll publish the results next week, but allow us to break the news to you here: iStill-made whisky blows anything else out of the water!

Do you want to test your whisky? Do you want our scientific advise on how to further improve it? Do you want to implement our recommendations and scientifically proof to your customers that your drinks are better than those of Big Alcohol? Under secrecy, yes, of course. Then please reach out to and order the iStill Laboratory Services.

9 thoughts on “Laboratory Verdict: Bourbon vs. Single Malt!

      • If this is scientific evidence what are you measuring in the graphs you published and what are the units?
        I am genuinely intrigued.

      • Hi Michael, we are measuring molecules that associate with hearts flavors, as well as heads and tails smearing. Measurement is in PPM.

      • Thank you for a speedy reply, I am keen to understand which “molecules” you are measuring and how, as a chemist/biochemist (retired) and occasional amateur distiller ( as well as brewer and winemaker) I find this topic fascinating and worthy of further study
        PS I am not trying to engage you in a lengthy response just honestly find your studies intriguing

      • Yes, I understand your fascination, Michael, we have the same over here. Hope you understand that we cannot disclose that information on an open forum. People that order our lab services of course get full insight. πŸ™‚

      • Understood and thanks for taking the time to reply. If money were no object I would definitely be a customer of yours, regrettably it is but I do enjoy your insights

  1. Odin, great news and great science!! Would it be possible to predict these characteristics from the grain alcohol right after distilling and before aging? I understand that aging itself will help enhance certain flavor profiles, but the flavors are already there, are they not? My question is directed as to save money in aging for products that may not have the characteristics in them already for a great aged product. It would be great to predict so as to experiment with different cuts but not having to wait the aging process to find out what happened. Thank you

    • Yes, for whisky and rum and brandies we can do that. We’ll use science to evaluate a new make and we can predict pretty well what you’ll get and when.

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