Terroir, that French concept of a combination of characteristics (soil, climate and human interaction) that express the soul of a place, is often used to define the individuality of a wine. In Burgundy, where monks began studying the soil as early as the 7th century to identify where to plant their vines, the concept of terroir is high art. It’s uniquely Bourguignon to talk about “Climats,” plots of land with precisely defined limits that take into account geography, history, archeology, grape variety, traditions, geology, expertise, landscapes, towns, genealogy, reason, passion, ancestral acts, customs, meteorology, oenology, culture, viticulture, toponymy and biodiversity.
They’re very serious in Burgundy about terroir. If you need proof, just consider that they have over 1,200 Climats across the region, and that all of them have names. Some are for geographical characteristics (Le Montrachet, for example, which means “Bald Mountain”). Others are named for manmade creations (such as Derrière le four, which indicates the presence of ancient coal ovens—four is French for “oven”). One of the best known is La Romanée, named for its proximity to an ancient Roman road.
Les Climats de Bourgogne had even received 50,000 signatures for its UNESCO World Heritage listing application in 2013, before being removed (along with the Caves de Champagne) this spring by the French Ministries for Ecology and Culture. Promoting wine in France always involves an element of suspicion from health authorities, so the government evidently felt safer choosing two alcohol-free contenders, the Grotte Chauvet with its prehistoric cave paintings in the Ardèche region and the volcanoes of Auvergne.
It would surprise many in France to learn that the wine region just behind Burgundy in knowing its soil so well is not Bordeaux. It’s actually probably the Mediterranean island of Corsica. I learned this last fall when I visited the CRVI de Corse (the Centre de Recherche Viticole or, in English, the Vineyard Research Center of Corsica) in the small village of San Giuliano on the island’s east coast.
The six-member CRVI staff supports the island’s wine industry with applied research in vineyard management, winemaking (oenology and microbiology), and native grape varieties and yeast. Agricultural engineer Gilles Salva is responsible for providing the island’s winemakers with vineyard management advice and research on 17 local grapevine varieties being grown at the center.
Natalie Uscidda, a microbiologist who studied at Montpellier’s school of œnology, works on wine fermentation and microbiology. Her research helped to develop the two, principal winemaking yeasts used on the island.
I also met with Lionel Le Duc, a soil engineer who has been studying Corsican terroir for the past 12 years (he also is responsible for the center’s œnology laboratory), to discuss the findings of his research, presented in July 2012 at the IXème Congrès International Des Terroirs Vitivinicoles.
Le Duc is passionate about geology. In fact his small office is filled with rocks and cloth sacks stuffed with soil marked with names like “Ajaccio” and “Cap Corse,” the areas where he collected the soil. His father-in-law, he says, sculpted architectural elements (grave markers, garden pieces, fountains, benches, etc.) in the largest marble quarry in Corsica. This got him interested in stone (he also sculpts, he says), and provided him access to stone samples from all over the island.
Complementing this artistic bent is his university studies in geology, biology and agriculture. Following a one-year internship at INRA (the Institut National de la Recherche Agronomique— France’s national agricultural institute), he did his one-year mandatory French military service in Toulon, where he was responsible for an analytical laboratory.
He began working at the CRVI in San Giuliano in 1998. Several years later he discovered a gold mine of information that at first glance might not have been evident to the average person. It seems that a geologist working with the BRGM (Bureau de Recherches Géologiques et Minières) in Corsica had spent the better part of his career making holes all around the island. This dedicated digger had made, in fact, over 10,000, 1.2m-square holes throughout the island’s 90,000ha of agricultural land. Using the data from these holes, along with others Le Duc made in selected vineyards using criteria developed by INRA that looks at soil mineral type, the soil density and its depth, the drainage potential, and other criteria (providing, as Le Duc puts it, “A basic unit of terroir”), allowed him to then use an INRA-developed 3D visualization software to create an interactive cartographical map of the soil structure in the island’s AOC wine appellations.
And since 2002, with money from the island’s regional development fund and the French government, he has set up a protocol to use this 3D map to examine the potential of the island’s three indigenous grape varieties—Vermentinu, Nielluciu and Sciaccarellu. This protocol consists of selecting parcels of vines within a vineyard that represent a desired standard (soil type, exposition, grape variety, etc.). Each parcel consists of approximately 100 vines of the same age, plantation density, clone and rootstock. The soil cultivation must be the same, as well as the vine management (pruning, shoot training, canopy management, etc.). To ensure consistency, the parcel is taped off from the other vines and Le Duc (or a CRVI technician) is responsible (other than for disease management, which is left up to the winemaker) for the soil and vine management within the parcel, including harvesting the ripened grapes.
Micro-vinification of the grapes harvested from each parcel produces approximately 30 bottles of wine. This wine is then analyzed in three ways. First, it is evaluated by a trained jury of tasters. A laboratory analysis is then done to determine its physical and chemical components. And, finally, the wine’s aromatic components are analyzed. Bottles in the CRVI cellar date back to the early 1980s, allowing the aging potential of the wine to be evaluated.
Most of the initial studies concentrated on the Balagne region that makes up the AOP Calvi appellation in northwestern Corsica. A total of 22 parcels have been studied over the past decade. But other study-parcels are located, or will be placed, in the island’s other eight appellations.
The real value of such a long-term study, he explains, is helping winemakers to increase the value of their grapes. A winemaker, he says, can then determine the best time to harvest the grapes to create different styles of wine (with more or less fruity flavors, with more or less color, with more or less aging capability, etc.). Such long-term studies can also show how different soil and vine cultivation techniques, different rootstock and clones, and different soil types affect wine quality.
As an example of the precision that is possible with such methodology, he cites the example of the Clos Culombu vineyard in the Calvi appellation. Winemaker Etienne Suzzoni has divided an already existing six-ha parcel into seven different micro-parcels with three different Vermentinu clones. Through micro-vinification of these smaller parcels he’s developed different Vermentinu cuvées that offer consumers different white-wine styles. Data from the parcels are also helping to produce Sciaccarellu grapes with increased color density, something that this variety often lacks in finished wines.
Digging a bunch of holes may never replace a millennium of observations by monks, but it is helping Corsica to understand its terroir better and to make better wine.