Terroir in whiskey ‘does exist’, distillery study finds

The preliminary results of a study exploring the influence of terroir on barley derived Irish whiskey has concluded that “environmental differences in whisk(e)y flavour are present”.

A study entitled the Whisk(e)y Terroir Project, which is a joint venture between Waterford Distillery and Enterprise Ireland alongside Dr Kieran Kilcawley of Teagasc; Dr Dustin Herb of Oregon State University; and independent whisky analysts Tatlock & Thomson, has completed its first year of research.

Defining terroir as “the 3D influence between microclimate, soil and place on a plant”, the study aims to understand the influence of the environment on whiskey produced from barley.

The project has used barley grown in two distinct sites in southeastern Ireland – Athy and Bunclody. While weather patterns at both sites “were comparable” to each other, their soil compositions differed, with Athy having higher levels of calcium (852 ppm higher), phosphorus (5.7 ppm higher), magnesium (30.8 pm higher), zinc (698 ppm higher), and an alkaline pH of 7.8 compared to Bunclody’s slightly acidic 6.6.

Two barley varieties – Olympus and Laureate – were sown at both sites and were subsequently analysed for 16 micro-nutrients.

The report findings noted that the grain compositions between environments diverged, with grain samples from Athy having increased levels of selenium, chromium, and tin, while Bunclody’s samples had increased concentrations of barium cadmium, zinc, copper, and aluminium.

The grain was then stored before being sent to be micro-malted “using a standardised base malt protocol to limit the confounding effect of the malting process”. The malt then went through a small-scale brewing and distillation process to standardised industry specifications. Sensory assessments were then made on the new make spirit with data collected both from panellist evaluation and gas chromatography.

Dr Dustin Herb and Waterford Distillery CEO Mark Reynier

The preliminary panelist sensory analysis found that new make spirit produced from grain grown in Athy had a higher level of fruit and malt flavours compared to Bunclody, which had stronger sulphur and grassy notes. However, the analysts did not report any significant differences in the two varieties for the flavour attributes that were tested.

The gas chromatography analysis indicated “significant effects” detected for eight metabolomic compounds. Among the findings, new make spirit from Athy was highest in furfural which gives notes of baked bread and almond with a sweet, bready, caramel and woody taste. Bunclody, meanwhile, was highest in n-propanol which delivers musty, fruity, apple, pear and autolytic aromas with earthy, nutty, fruity and bubble gum flavours.

According to Dr Herb, who wrote the initial report, “preliminary results of the first year’s data indicate that environmental differences in whisky flavour are indeed present, however more data is needed to fully understand the role in which environment and variety play in the flavour and terroir of whisky.”

However, the experiment was conducted on new make spirit rather than ‘whisk(e)y’ which must undergo a maturation period of three years in oak in order to be labelled as such. Therefore, it will be interesting to see if the differences are as notable once the spirit has been matured.

Waterford Distillery CEO, Mark Reynier, added: “In the fine wine world, terroir is a fundamental tenet, a principal that is understood and accepted both by markets and buyers as by growers and legislators. Yet oddly enough no one appears to have proven the concept scientifically. That is what we have set out to do here. And what is more, to show that terroir can apply as much to barley and single malt whisky as it does to the vine and fine burgundy.”

The next phase of the project will analyse gas chromatography findings from Dr Kieran Kilcawley, with the full results scheduled for publication in Autumn 2019. The project is also expected to go beyond the initial scope and continue until 2020.

Describing itself as “terroir-focused”, in November last year Ireland’s Waterford Distillery proved it was just that by hiring a ‘terroir agronomist’, a position designed to boost its understanding of the differences in flavour in distillates produced from barley grown in different areas.

Grace O’Reilly, who took up the position last year, will help to oversee and manage the distillery’s relationships with its barley growers. In addition, she will continue the company’s research into flavour differences observed in whiskies produced from barley grown in different regions, using data obtained from 71 different farms.