Flavour differences in whiskey can be discerned based solely on the environment in which the barley used to make the whiskey is grown, a new study suggests.
This is the first scientific study that found the environmental conditions, or terroir, of where the barley is grown impacts the flavour of whiskey, according to researcher Dustin Herb from the Oregon State University.
“Understanding terroir is something that involves a lot of research, a lot of time and a lot of dedication. Our research shows that environmental conditions in which the barley is grown have a significant impact,” Herb said.
Initially, the team focused on the contributions of barley to beer flavour. Their research found notable differences in the taste of beers malted from barley varieties reputed to have flavour qualities.
Then, the team attempted to answer the question of whether terroir exists in whiskey.
Herb designed a study, published in the journal Foods, that involved planting two common commercial varieties of barley in Ireland, Olympus and Laureate, in two distinct environments — Athy, Co. Kildare and Buncloudy, Co. Wexford in 2017 and 2018.
Athy is an inland site and Buncloudy is a coastal site. They were selected in part because they have different soil types and different temperature ranges and rainfall levels during the barley growing season.
The crops of each barley variety at each site in each year were harvested, stored, malted and distilled in a standardized way. Once distilled, the product is called “new make spirit.” (It isn’t called whiskey until it is matured in a wooden cask for at least three years.)
The researchers used gas chromatography mass spectrometry and the noses of a six-person trained sensory panel to determine which compounds in the barley most contributed to the aroma of the new make spirit.
That analysis, along with further mathematical and statistical analysis, found that the environment in which the barley was grown had a greater contribution to the aroma of the whiskey than the variety of the barley.
In Athy, it was more positively associated with sweet, cereal/grainy, feinty/earthy, oily finish, soapy, sour, stale and mouldy sensory attributes and in Bunclody it was more associated with dried fruit and solventy attributes.