In our previous blog posts we’ve talked about copper, the still and also barrels, the importance of coopers, and the origin of the wood itself but today we’ll be moving onto Single Malt Whisky’s namesake ingredient: malted barley.

But it’s the cask that matters, everyone says that…

The barrel is responsible for 60%-80% of a whisky’s flavour – a phrase most anyone whose ever taken a distillery tour has heard.  A phrase that sound like it was first espoused by a 16th century travelling monk perched on the hill of Leith under the ever present aura of Edinburgh castle while sipping Uisge Betha from his quaich.  In reality the first appearance of the phrase or any similar statement that we could find was in a press release from Glenmorangie from the mid 90’s discussing the then controversial use of finishing casks (I actually lied, after a very unfruitful search we found this tidbit in a blog post from Waterford Distillery in 2017 who also discuss the misnomer that whisky is all about the cask to the exclusion of other very important factors).

This seemingly quite believable piece of whisky marketing jargon has become ubiquitous to the extent that when discussing single malt whisky people often jump straight to the barrels, the oak, the charring, the years of maturation and discuss usually only those factors.  But the production of whisky and the development of flavour is holistic and is shaped by every stage of the whisky production process.  Meaning long before spirit touches the inside of a cask, its character and soul is already being shaped in the field as young barley corn grows.

Barley as a Flavour Vector

At Deviant Distillery, we believe in optimising every step of the whisky making process, and that means starting with the most important ingredient of all: malted barley.  It’s easy to think of barley as just a sugar source, something for the yeast to digest during fermentation.  But malt barley is much more than that, it’s a biochemical powerhouse and a key driver of flavour that too often gets overlooked.  It is what separates whisky from rum or brandy whose production is ostensively identical after the starting materials have been processed into liquids.

The barley used in single malt whisky is malted, meaning it has been tricked into germinating to develop the enzymes needed to convert starches into fermentable sugars then kilned to stop any further growth and dry out the malt.  That enzymatic activity is critical for brewing, but it’s not the only thing barley brings to the table, it contributes proteins, lipids, minerals, and a raft of flavour compounds that survive the rigours of fermentation and distillation.  The way the barley is kilned also contributes significantly to its impact on whisky flavour.  Think of the spectrum of character between pale ale, amber ale, and a stout, those are the characteristics that can be derived from modifying the kilning process.  Controlling these factors and working with different levels and types of kilning produce distinct sensory differences in the final spirit. Grassy, fruity, biscuity, creamy, even chocolate and earthy characteristics, these aren’t just the result of yeast strain or cask type, they’re derived from the malt itself.

Terroir in Whisky? 

Wine has long embraced the concept of terroir—the idea that a product is a direct reflection of the land where it was grown.  Whisky is starting to catch on and catch up.  Barley grown in one part of Australia will have a different mineral profile, protein content, and moisture level than barley grown in another part of the country.  These variations may seem minor, but during fermentation and distillation, they cascade into different congeners, esters, and phenols being contributed.  These in turn shape everything from aroma to mouthfeel.

It’s not just where the barley is grown either, but what kind of barley is used.  Over the past few decades, the broader whisky industry has gravitated toward high-yielding, fermentation-friendly barley varieties. But those choices often prioritise efficiency over flavour.  Heritage and experimental barley varieties, like those incorporated into both our peated and unpeated whiskies courtesy of Australia’s own Voyager Craft Malts show that genetics matter.  At the cost of lower yield, these oft overlooked varieties contribute distinctly and uniquely to flavour profile in whisky new make spirit.  While one variety may lean toward nutty or oily characteristics; another may be light, floral, or citrus-forward all of which can be used in symphony to create a multidimensional product.

What This Means for Our Whisky

At Deviant Distillery, we’re obsessed with fermentation science, and barley is central to that obsession.  Malt barley is not just as a source of sugar, but a genuine and integral source of character and complexity, more than that it’s the soul of Single Malt Whisky.  As more distillers and drinkers start to appreciate the nuances of grain origin, variety, and kilning, we’re excited to be part of that conversation.  More importantly though were dedicated to keeping malt as not just the namesake component of single malt whisky but an equally important contributor to character and providence of all the whiskies we produce.