Researchers Use Geographic Information Systems to Quantify Impact of Place on French Wine

That is, the difference that soil, weather and location make in the taste of a vintage. The French refer to it as “terroir,” and the researchers' goal is to scientifically identify and map terroir categories that will benefit the producers who make wines and the connoisseurs who enjoy drinking them.

Shawn Hutchinson, a K-State associate professor of geography on sabbatical in France, is working with Michael Gay, a professor at the University of Toulouse-Ecole d'Ingenieurs de Purpan. They are using geographic information systems — known as GIS — to quantify the impact of place on the quality of grapes and the wine that is produced.

“Few wine enthusiasts would confuse a wine originating from Bordeaux with one from the Languedoc region of France, even though they might have been produced from the same species of grapes,” Hutchinson said. “While the traditional wine making processes employed in those areas certainly contribute to differences, of equal importance is where and how the grapes were grown, including differences in weather, soils and topographical orientation.”

Hutchinson said it is widely known that how and where grapes are grown and enological practices have significant impact on wine quality. However, he said few have established a quantitative link between place and quality.

To establish this link, Hutchinson and Gay are looking at the following data from the study area in southwest France: elevation, topographic slope, surface curvature, hours of sunlight and solar radiation during the growing season, and the topographic wetness index, which measures how moist soils may become during a precipitation event.

Then, the researchers are classifying the data to map where the data are similar. In their preliminary results, Hutchinson and Gay have found 10 distinct terroir classes in the Saint Mont region of southwestern France. Next, they will determine whether the vineyards in these terroir classes produce grapes — and ultimately wine — of differing quality. They will measure quality based on chemical analyses performed after the 2008 harvest, looking at elements like acidity and alcohol content.

“What we want to do is provide a scientifically valid but market-oriented name to each of the 10 terroir classes, assuming, as our early statistical analyses show, that they are directly correlated to wine quality,” Hutchinson said. “Many wine enthusiasts, but especially the French, are very interested in knowing how and where their foods have been grown. The ability of a wine cooperative to include a terroir class in the label information will be well received by French consumers, as it helps meet this informational need.”