Science is something of a dirty word in the whiskey business. Consider the life and work of Aeneas Coffey. After risking life and limb as a gauger, he applied all he knew about distilling (and a lot of what Scots inventor Robert Stein knew) to a new type of still. It was cleaner and more efficient, and was rejected wholesale by the distillers here. The Scots, however, were more receptive to his more efficient and cost-effective invention, and the rest is history.

In Ireland, Coffey’s still was seen as an affront to whiskey, making silent spirit that had no tongue to speak from whence it came – or, to put it another way, it was so pure that you supposedly had no idea what was in it.

To this day, the spirit produced by the Coffey still is seen by whiskey drinkers as the child of a lesser god, rather than the result of a brilliant invention. Of course, its purity does give it a lighter flavour profile in comparison to single malt or the spicy mixed mash of pot still whiskey, but it’s still an example of how the scientific advancement of distilling is not always welcome.

Modern ‘advancements’ haven’t helped the average whiskey drinker change their quasi-Luddite minds – accelerated aging techniques, which range from spirit mixed with wood pellets, to ultrasound used on barrels, to the oldschool sherry hack of paxarette, are really just ways of cheating time. And time, as any human being will tell you, cannot be cheated.

But what is it that makes a whiskey great, beyond any subjective preferences, beyond any labels or marketing? What is the secret to a great whiskey? 

If you wanted to ask someone, Dave Quinn is a good person to start with. He was part of that first generation of distillers who focussed on the idea of whiskey as a molecular event that needed to be explored – people who saw distilling as a science as much as an art.

From Longford, he went to college in Galway where he studied biochemistry and then biotechnology. Moving to Cork he started working with Irish Distillers in the 1980s, before transferring to Bushmills – then owned by IDL – in 1996, before transferring back to Midleton in 2002, where he is now their Master Of Science. But what exactly is the science of whiskey?

“Science is just a way of saying we are trying to find a better way of understanding what’s happening right down at the molecular level – understanding the link between what we describe as flavour and taste, and what are the congeners, what are the flavour compounds that actually contribute to that, to what you perceive as taste, flavour, aroma, and we have a certain level of understanding of that but not a complete one by any manner or means,” he says.

Of course, making whiskey isn’t a one step affair – and parts of the process are easier to understand than others, particularly those at the front end.

“It’s easier to understand the biochemistry of brewing and yeast fermentation, what happens to the yeast, the compounds it produces. Where things start to get a bit more tricky is when we get into wood maturation. We have an understanding of some of the wood compounds that contribute but there is a lot of other wood compounds that we don’t fully understand or know about.”

But long before the spirit comes into contact with wood, Quinn and his colleague Dr Dagmara Dabrowska have a way of studying distilling. Squirrelled away within the Midleton campus is a pilot plant – effectively a fully functioning scale model of the distillery, in the style of Derek Zoolander’s school for ants. Initially created as part of their proposed energy saving programme, it began life as a 1/2000th version of the grain columns, and it is here that much of their work takes place.

“We have a pilot plant up there, where we have small pot stills and a column still so we can work on them there without even coming down here to the microdistillery. The pilot plant is very much more … automated isn’t the right word, but with more places where we can take samples and monitor a lot of the variables like temperature and pressure. With the energy saving programme we did a lot of that work in the pilot plant.”

The energy saving was one of the most impressive feats of an already impressive operation in Midleton. The pilot plant was commissioned to conduct R&D into the proposals, which saw them shave 20% off their energy use. Dr Dabrowska is credited with much of the success of that project. As Head of Analytical and Technical Development, she helped find new ways to transfer energy between the columns – a piece of equipment that, Aeneas Coffey would be delighted to know, produces more spirit than any other part of Midleton distillery. Their colossal grain output was finally celebrated with the recent release of both the 31-year-old and 11-year-old single grain bottlings, the distillery’s first under their own name (the Irish Whiskey Society released a Midleton grain bottling two years ago).

Launched under the Method & Madness incubator brand – a space for IDL to experiment with their output – the grain whiskeys were a striking departure from the heritage pot-still brands like Redbreast and Yellow Spot to a more modern aesthetic and an embracing of science. But whiskey is all science, despite what the marketing department might tell you. The modern distillery tries to site itself in a romantic pastoral dreamscape, where the distiller hand operates all aspects and divines the perfect cut using only his senses. The truth is rather different. Modern distilleries have more in common with pharma plants than the sort of thatched-cottage scenes on their labels. Distillers are – and always have been – scientists. But it is in the collision between the quantifiable perfection of science and the beautiful chaos of human nature that some of the most interesting interactions take place, as Quinn points out.

“For example, somebody is doing a sensory evaluation trying to use normal everyday words to describe the flavour that they are seeing or feeling, to try and take that –  say somebody saying I get a nice hint of floral note, a bit of rose petal and a bit of leather, and cigar tobacco in the background – there is no way that you could say well that is due to ABCD or E, as different people will have different terminology and different language to describe what they perceive as flavour.

“So one of the things we do in our sensory science lab is to try and standardise the language a little bit so that if somebody does say leather or cereal notes or whatever, we try and ensure that everyone uses the same language to describe that particular attribute in the whiskey. And then we might try and see if we can determine what is causing or what is contributing to that.”

But while the pilot plant and sensory science lab may be akin to the Large Hadron Collider, there is no one illusive God Particle that can create a particular flavour.

“Invariably it is not just a single congener – it could be the effect of multiple congeners coming together to give you a single sensory effect. You have some compounds that on their own … – you find a single compound and put it into neutral alcohol and increase its concentration so you get to a point where you could actually perceive it as an aroma , and then if you go below that minimum level and you don’t get it then that is deemed the flavour threshold – in other words, you have some compounds that have very high flavour threshold, in other words you need a lot of them for you to perceive it.

“But then some are very low flavour thresholds, levels that you can barely measure, but you can still pick it up on the nose. And it is those compounds that are the key ones in terms of bridging that gap between identifying the sensory act of compounds and identifying them and relating them to a particular character.

“What can happen is that you can get small individual compounds that might be below the flavour threshold; in other words, theoretically you should not be able to pick them up. But there’s a few of them that are sometimes present together that can almost act synergistically so that individually you wouldn’t be able to detect them but when they are combined together they give you a flavour and perception. And then you are getting into an area that can be very difficult to fully explore.”

That ‘area’ is us. Our perceptions are based on a combination of nature – the senses we are born with – and nurture – the tastes we develop as we grow, which are impacted on by the culture and environment around us.

“Different people will have different preferences, different likes, even different sensitivities to flavors so there will  be some elements of flavour that some people will pick up readily and other people cannot perceive them at all.”

Quinn’s work with Irish Distillers is less about stripping the soul from whiskey than it is about understanding how to make the best whiskey possible. It may seem like a eugenics programme, where error and, thus, personality, are eliminated under the jackbooted march of lab technicians in white coats, ruthlessly striving for a dystopian purity. In reality, it is what science always aims to be – about doing better.

“We are trying to understand distilling at a molecular level. The key is – the more you can understand, the more you can make informed decisions about what influences the taste or the character of whiskey. But it is also about what aspects don’t affect it. If you don’t have some level of understanding then you can’t really go and do the same distillation with confidence. You can only do this if you have a good understanding of the technical, science element of what you’re doing, because if you’re just relying on old wives tales and superstitions about not changing anything in the distillery, then you will never be able to develop something unique and interesting.”

Quinn knows a thing or two about doing unique things, given that, along with Peter Morehead, he was one of the chief drivers of the runaway success that is Jameson Caskmates, inspired by a spirit of innovation, experimentation and adventure.

But while the Method & Madness brand has the space for more mad-scientist style experimentation with wood and distillate styles, in both the main distillery and micro distillery, part of Quinn’s work is to ensure that as the Irish whiskey category explodes worldwide, a consistent standard is maintained, not just of quality but also of flavour profile. Distillers used to be full of superstition, where any change to the process – even the cleaning of cobwebs in the stillhouse – was deemed to be bad luck in case it affected the spirit, a culture of what a scientist might refer to as ‘poppycock’.

“You can keep doing the same thing over and over again but if you have a better understanding of what the fundamentals are then you have a much better opportunity of directing your research and your experiments in a path you know will change the spirits, and you can say ‘let’s try it’ and know more or less what the outcome is going to be. You go from a chancing-your-arm, needle-in-a-haystack approach to having a far more focussed approach.”

The distillery in Midleton is one of the most impressive, modern facilities in the world, and it has shown that you can be the biggest and also be the best. While the public facing side may be one of heritage and tradition, scientists like Dave Quinn, Dagmara Dabrowska and the rest of the Masters and their apprentices have shown that they are getting ever closer to unlocking the secrets of a perfect dram and entering a brave new world of truly great whiskeys.

• Footnote: There is an excellent interview with Master Distiller Brian Nation in the Engineering Journal, which you can read here. It goes into some depth on the energy saving programme. There is also a recent presentation by Dr Dabrowska which you can read here, which goes into her work on the column stills.