The idea of whisky (and indeed whiskey) having a provenance in the same way wine does has long been a contentious issue. Is it possible for a distilled spirit to take on the flavours of the barley used to make it?
It’s a question that was instrumental in the founding of the Waterford Distillery by Mark Reynier and a newly released study suggests that he could be right, that indeed what goes in affects what comes out.
The peer-reviewed study has found a link between flavours of new-make Irish spirit and the origin of the barley used to produce it. Within the barley production, the influence of soil, microclimate and topography were all shown to have an impact on the final flavour of the whisky.
The concept of terroir has long been accepted in other drinks categories such as wine and cognac, but has polarised whisky experts for years.
The paper, published on 17th February in scientific journal Foods, spearheaded by Waterford Distillery, proves that terroir can also be found in barley, and significantly, the single malt whisky spirit distilled from it.
The first paper from The Whisky Terroir Project examined two barley varieties grown on two farms with separate environments in 2017 and 2018: Athy, Co Kildare, and Bunclody, Co Wexford.
Each sample of barley was micro-malted and micro-distilled in laboratory conditions to produce 32 different whisky distillate samples. These were then tested by whisky lab analysts and using the analytical methods of Gas chromatography–mass spectrometry–olfactometry (GC/MS-O), as well as sensory experts.
Key findings include more than 42 different flavour compounds, half of which were directly influenced by the barley’s terroir.
The sheltered inland Athy site had predominantly higher pH levels with increased amounts of Calcium (Ca), Magnesium (Mg) and Molybdenum (Mo) in its limestone based soil. It had consistent, higher temperatures and lower rainfall. Whisky new make spirit made from this barley was characterised by toasted almond notes, and a malty, biscuity, oily finish.
The more exposed Bunclody site had lower pH levels with increased amounts of Iron (Fe), Copper (Cu) and Manganese (Mn) in its soil, which is based on a shale or slate bedrock. The farmland is closer to the coast and was typically subject to more volatile weather. Whisky new make spirit made from this barley was lighter and floral, with a flavour of fresh fruitiness.
The findings of the study are significant for the whisky industry as the presence of terroir within the spirit distilled from barley creates the possibility of producing regionally specific whiskies in the same vein as wines, potentially an Appellation Controlée system of provenance.
Mark Reynier, Founder and CEO of Waterford, said: “Barley is what makes single malt whisky the most flavoursome spirit in the world. This study proves that barley’s flavours are influenced by where it is grown, meaning – like wine and cognac – whisky’s taste is terroir-driven.”
“Critics claimed any terroir effect would be destroyed by the whisky-making process, saying there is no scientific evidence to prove that terroir even exists. Well, there is now.”
Dr Dustin Herb, Lead Researcher and Post-doctoral research at Oregon State University, said: “This interdisciplinary study investigated the basis of terroir by examining the genetic, physiological, and metabolic mechanisms of barley contributing to whisky flavour. Using standardised malting and distillation protocols, we preserved distinct flavours associated with the testing environments and observed year-to-year variations, indicating that terroir is a significant contributor to whisky flavour.”
Professor Kieran Kilcawley, Principal Research Officer at Teagasc, said: “We utilised gas chromatography olfactometry which enabled us to discern the most important volatile aroma compounds that impacted sensory perception of the new make spirit. This research not only highlights the importance of terrior, but also enhances our knowledge of key aroma compounds in whisky.”
This first step of the project explores the terroir impact via a laboratory malted and distilled spirit for complete production uniformity. The next stage – which will be published in 2022 – further explores the same role of terroir in whisky, this time using analysis based on Waterford Distillery’s own commercial spirit and matured whisky.