Can Scientific Rigor Describe Wine Terroir?

As researchers discover more about vineyards, they're urged to provide science for the concept of place

by Peter Mitham
scandanavia u.s. wine sales
Wine critic David Schildknecht speaking at the XI International Terroir Congress.

McMinnville, Ore.—What does terroir mean in an age of big data and social media, a world awash in information yet still unable to agree on the distinguishing role of place in winemaking?

When scientists from a variety of disciplines gathered in Oregon last month for the XI International Terroir Congress, the question was a hot topic. Between dozens of papers that reported results from projects around the globe that seek a better understanding of the conditions under which grapes grow and wines are made, several papers dug into the thorny issue of what we talk about when we talk about terroir. “It’s been so abused as a marketing tool,” wine critic David Schildknecht told the assembled scientists in a no-holds barred presentation. “Unless it walls something in and walls something out, it’s not going to be useful to discuss anything, scientifically.”

It’s a simple case of good fences making good neighbors, to quote Robert Frost: with fields of data available to researchers, there’s got to be some way to organize and bring meaning to what might otherwise be an embarrassment of riches.

A wealth of data
And the riches are piled high: Joaquín Cámara of the Technical University of Madrid, for example, has compiled data on 80,892 vineyard blocks in the Douro region of Portugal using the Balanced Entropy Index (BEI) to better understand the characteristics of vineyards; in North America, Andy Reynolds of Brock University’s Cool Climate Oenology and Viticulture Institute has flown drones over vineyards to develop a database of Normalized Difference Vegetation Index (NDVI) readings to better map vineyard variability.

But data can’t obscure the vines, said Kees van Leeuwen, a viticulture professor at Bordeaux Sciences Agro, part of Institut des Sciences de la Vigne et du Vin in Bordeaux. “We must put the vines in the middle of the terroir,” he said. “Terroir is all about the interaction of the vine and the natural environment.”

While mapping can provide important knowledge about the environment, and monitoring of vine water status and nitrogen levels provide insights on the well-being of the vine, terroir is the result of the equation the two sets of variables form. If good, measureable data is going in, then the result should also be measureable.

This is where prohibitions on practices such as irrigation, which France had for vineyards producing Protected Designation of Origin (PDO) wines until 2006, may influence the expression of terroir while being independent of terroir itself.

Cécile Coulon-Leroy, a viticulture and enology researcher at Ecole Supérieure d'Agricultures in Angers, explained that many producers see irrigation as important for canopy management, and helpful in complementing rainfall in dry years.

The wealth of information now available about the many variables affecting vine development has led many experts to believe the genetic composition of a vine is far more significant an influence on terroir than management practices. As a result, irrigation is seen as a way of supporting the vine’s expression of its location.

Moreover, a survey of 492 consumers found that younger consumers are more likely than older drinkers to accept irrigation as a specific management practice that supports rather than interferes with the expression terroir.

Think of the consumers’ perception
The openness underscores a point that Ulrich Fischer of Germany’s Institute for Viticulture and Oenology at DLR Rheinpfalz in Neustadt made regarding the abstract nature of terroir for most people without some measureable difference. “Terroir differences without sensory significance is an academic concept with little impact on the market,” he said, arguing that growers and winemakers need to understand where consumers start to notice and recognize terroir, and start making decisions based on their experience of a wine. “I think sensory diversity is a new synonym for wine quality. … And terroir is an important part of that diversity.”

Scientists can perform all the research they like to define terroir, and winemakers can try to explain it to them, but if consumers don’t experience it then it simply isn’t real for them. This is where Schildknecht, a wine reviewer for The Wine Advocate newsletter, first developed his own appreciation of terroir as something that distinguished wine from different regions and locations within those regions.

Geology might be a beautiful thing he said, but how does it influence wine? Sipping samples of Oregon wine in soil pits dug for the congress participants helped scientists draw a connection between site and their sensory experience of wines made from adjacent fruit, but Schildknecht warned against anyone mentioning the idea of minerality. “What sizzles to sell wine is exactly the wrong thing if you want a clean concept,” he told scientists. “If we want to embrace scientific rigor, we have to do it in a constructive way.”

That means greater investment in basic research that can puts facts behind the differences people try to pin on terroir. It also means fighting for the funding to make it happen.

While funding has been tough to get in recent years, and many projects win funding by promising to focus on understanding popular and pressing concerns such as a climate variability, Schildknecht said cleaning up the idea of terroir and applying the idea correctly would help ensure research results were understood correctly. “Having a clean concept, at least as a tool, is a start,” he said. 

Posted on 08.26.2016 - 10:10:00 PST
I strongly believe arbuscular mycorrhizal fungus is the prime transformer of local mineral passed on to the vines, in this symbiotic work the vine is supplied with needed minerals and the fungus with carbohydrate nutrients, the result is storage of a "chemical equation" stored in the skin and it become the job of the oenologue to capture that particular taste through maceration extraction to obtain the terroir taste attributed to the soil on location of the vines. For that reason i am of the opinion : you can not compare wines let say a Pinot Noir from Burgundy against other regions, but contemplate each wine for what a particular terroir has to offer.
I firmly believe it does apply to all varieties.

Posted on 08.26.2016 - 12:42:38 PST
I think Mr. Fitoussi has given us a lot of “something” to answer David Schildknecht’s proposition: “Unless it walls something in and walls something out, it’s not going to be useful to discuss anything, scientifically.” It looks very similar to me, to positions of politicians and scientists on “Climate Change.” Joaquin G. Zoque