The term terroir is common in wine. Many consumers understand that the flavors and aromas of wine can reflect the grapes, soil and other terrain aspects from the vineyards.

So if whiskey is made from grains grown similarly on a farm — with purpose and attention in where and how cultivation occurs— then why would terroir not also apply to distilled spirits?

Yet the word is not typical with whiskey, or at least not nearly as common as in describing wine.

Does terroir matter in whiskey?

This question is at the center of recent work by Rob Arnold, master distiller at the Fort Worth-based Firestone & Robertson Distillery, which is behind the fast-growing TX brand of whiskeys. With a master’s in biochemistry, and pursuing a PhD, Arnold has led research into the subject. He helped publish a research article on the subject last summer, and has a new book set to release towards the end of 2020, entitled The Terroir of Whiskey.

“‘Terroir is at a minimum synonymous for the growing environment, and more accurately for how a specific grain variety expresses flavor through its environment,” he says. “A scientist would phrase this as the interaction of a variety’s genes and the environment in which it grows.”

In the study from the article, Arnold and a team of researchers analyzed three different corn varieties across a number of Texas farms. They explored whether differences in grain and location (or terroir) would measurably affect the end-result flavor compounds of whiskey.

The research suggests: yes.

“A lot of the flavor compounds important for the flavor in whiskey showed a meaningful variation due to the terroir,” Arnold says. “After all, we are feeding these grains to the yeast as food in the mash. The chemical variation in corn does impact the flavor compounds that are the byproduct of yeast.”

After all, different types of corn, barley or other grains obviously produce different-tasting whiskeys. (Hence the recent rise in distillery’s using unusual mash bills.) So why wouldn’t changes in the varieties and growing environment of those grains also affect what ends up in the bottle?

For counterpoint: What exactly is left over in that bottle? Those original grains went through significant changes during the course of an extensive production process, argues Robin Robinson, longtime whiskey writer, consultant and former brand ambassador for Compass Box Whisky Company. Robinson recently published on this subject as well, as part of his new book, The Complete Whiskey Course.

“The word that properly describes what distillers are doing is not ‘terroir’, which means ‘of the earth, but provenance, which means ‘of the origin’,” Robinson says. “Think about it. You’re putting ‘of the earth’ into a fermented stew, which is then heated with catalytic effect in a pressurized, closed environment made of metal copper, and then distilled and taken apart in cuts and finally put into a barrel. I don’t see how there can be any ‘of the earth’ left. As soon as you light the fire under the pot, that’s the end of terroir.”

Whereas with wine, he argues, more “of the earth” remains in that final bottle because of the less-intensive production process. “Wine production can occur naturally whether we’re there or not,” Robinson points out. “Whiskey is a manufactured product, and there’s not a terroir thing about a manufactured product.”

Robinson believes that “terroir” in whiskey is a marketing technique. “Craft distillers are all over this term because they’re looking for differentiation.”

Presented with the findings of Arnold’s research, Robinson counters that “with scientific papers, if you know where you want to end up, you can find evidence for it.”

An outspoken personality within the whiskey community, Robinson made waves on this subject during a series of panels late last year on American single malt whiskey. A longer counterargument from Robinson can be heard in a November podcast from one of these panels, recorded on WhiskyCast by fellow media veteran Mark Gillespie.

Other distillers spoke up during these panels in defense of whiskey terroir.

“Westland fundamentally believes that . . . there is a sense of terroir in grain,” says Chris Riesbeck, commercial director at Westland Distillery, during one panel. Westland is among the leading producers in America in terms of reflecting region in whiskey. “The fact that there is an argument to this is surprising, because, quite frankly, everything that grows grain is located in that place. That sense of place is what terroir is all about.”

“Over the next few years we’ll be making releases that are highly specified to the regions where the grain comes from, that we, in just early sampling from cask, can recognize significant differences in the quality of the grain coming through,” Riesbeck adds. “If you grow a potato in Connecticut, if you grow a potato in Maine, if you grow a potato in Idaho, they all taste different. Why shouldn’t that extend past that?”

But what about after you run those grains through the full production process? Does that destroy the original sense of terroir?

“You can’t destroy matter,” says Arnold of Firestone & Robertson. “You can’t destroy the chemical compounds through the production process. The chemical building blocks of flavor start with the grain.”

Like Riesbeck of Westland, Arnold is surprised that there is even such an argument over whiskey terroir. “This is an established scientific phenomenon,” he says. “Nutrient compositions of grain change because of where and what the grain came from.”

Part of the problem with further establishing terroir in whiskey, Arnold believes, is because most distilleries buy grain in bulk commodity, meaning their grains come from many varieties and farms, mixed together. That mass mixing negates terroir. In comparison, Firestone & Robertson works with only one farm, located an hour south from Fort Worth, giving the distillery significantly greater control over grain cultivation.

“The most important part in the terroir argument today, I think, is the idea that distilleries have to choose whether or not to follow it,” Arnold says. “I believe that the pursuit of terroir is the next big thing in our industry.”

Which would require more research into flavor compounds, and how they are affected by the environment and whiskey production process.  

“Does terroir impact flavor? Yes,” Arnold says. “But how much? That’s hard to quantify, no matter what we’re talking about.”

Kyle Swartz is editor of Beverage Dynamics magazine.