Roger C. Bohmrich, Master of Wine
December 2017

Terroir, not long ago a word spoken mostly by French vignerons, is now heard around the world of wine. This does not signify universal agreement as to its meaning or validity. Some believe terroir refers only to environmental factors which influence the grapevine, particularly soil, climate and topography. Others define terroir more broadly as a holistic concept embracing not simply the givens of the natural world, but also the contributions of wine growers and makers. Which of these interpretations makes the most sense? Or is the outright rejection of terroir as a meaningful and useful construct justified, as some skeptics maintain?

The notion of the importance of place – one synonym for terroir – has its origins in ancient times. Ancient Egyptians created hills in the flat Nile Delta to enhance exposure of their vines. The most celebrated wine of Rome, Falernum, was grown on Monte Massico in Campania and was classified by vineyard location: Caucinian, at the top, Faustian on the uppermost slopes, and Falernian on the lower hillside. This sort of differentiation according to specific topographic and climatic features is at the heart of terroir.

The word itself, according to French etymologists, is derived from the Latin territorium and the later terraire. The French word for earth, la terre, shares the same root, and many infer that terroir is essentially soil; unfortunately, this self-limiting interpretation is often put forward by wine growers themselves. Territorium meant simply the cultivable land attached to a community. At its origin, in other words, the conceptual basis of terroir was straightforward: a piece of ground suitable for a crop.

The stories of medieval monks in Burgundy attentively cultivating small vineyard plots – predecessors of today’s climats – and even tasting the soil have been repeated in countless accounts. Marion Foucher, an expert in Burgundy’s monastic orders at ARTéHis (Université de Bourgogne), dispels many of these fables. Not long after the Cistercians founded their abbey near the Côte d’Or (1098) and constructed the Clos de Vougeot (1160-1170), Foucher says, they turned the vineyard work over to hired laypeople. Moreover, the monks combined grapes from multiple parcels to make one Cistercian cuvee rather than single-site wines. It is really only in the modern era, perhaps beginning with the very first comprehensive vineyard atlas authored by André Jullien in 1816 (Topographie de tous les vignobles connus), that “terroir” has been vested with embellishments and nuances to explain (or speculate) why a certain site may yield wine with distinctive flavor characteristics, and why one vineyard is superior to another nearby.

There is general agreement that the physical environment and prevailing climate are cornerstones of the terroir concept. This is, after all, common sense rather than a complex empirical theory. Academics may debate how many angels can dance on the head of the terroir pin, but it should be self-evident that the natural milieu bears on the life cycle of the plant, the production of fruit, the chemical composition of the juice and, ultimately, at least some of the characteristics of the wine.

Climatic factors such as air temperature, precipitation and seasonal patterns are fundamental. Many theoreticians argue that climate plays a dominant role outweighing all other parameters. At the XIth International Terroir Congress, Cornelis Van Leeuwen, head of the viticulture and enology department at Bordeaux Sciences Agro, explained that ambient temperature has a determining effect on the potential to grow wine grapes, setting the global boundaries and determining which varieties will succeed in a particular location. In turn, a wine’s basic profile – what is commonly called a “cool” or “warm” style – is related to climatic drivers, as is the variation from one vintage to another. Soil temperature may affect the ripening timetable in any given season but is far less consequential than air temperatures.

Soil is host to the vine, supplying water to the roots as well as essential nutrients. Viticulturist Richard Smart maintains that, while climate drives wine style and quality, “terroir effects are far more frequently soil rather than climate effects.” There is a subtle distinction in this view. Smart and Gérard Seguin, the original decoder of terroir in Bordeaux, say soil physical properties are fundamental in regulating water supply to the vine. This is of particular relevance in temperate climates with adequate – or at times excessive – rainfall during the growing season. In these places, notably many celebrated European regions such as Bordeaux and Burgundy, the structure of the soil is central to the quality hierarchy of vineyards. The physical construction is far less influential in locales with negligible precipitation while the vine is in leaf; for example, Napa or Columbia Valley. These and many other arid New World regions are dependent on irrigation. In such environments, just the right amount of water can be delivered to the vine at just the right time, taking soil and other conditions into account. This all-important distinction goes a long way to explaining why many in the New World at first contested the importance of soil, and terroir more broadly, when the word entered the global lexicon in the 1970s.

It is important to note that, while soil structure is critical in rainy growing seasons, soil chemistry is comparatively insignificant. Wines of recognized quality are produced on nearly every soil type from acid to alkaline. Although many have studied soil chemical constituents in the hopes of discovering a “secret ingredient” to explain the organoleptic differences between, say, Musigny and Chambertin or Château Latour and Lafite, no one has established a cause-and-effect link between any single element and wine characteristics or quality. Of all the possibilities, nitrogen is fundamental, affecting the vine’s vigor and the composition of the grapes; but of course nitrogen is a universal nutrient that can be added if needed in the form of fertilizer.

Despite many claims to the contrary, there is no direct connection between geological minerals in soil and rocks and wine flavor, including fossils, even if they have romantic appeal. A very few minerals in wine may be perceived by suitably sensitive tasters as salty or perhaps bitter: potassium, sodium or calcium chloride. Even so, the concentration of these salts would have to be atypically high – sodium in wines from vineyards close to the sea, for example – to be detected by human palates. It is not a surprise, therefore, that recent sensory studies reveal “minerality” to be a surrogate for primary tastes, not a literal descriptor. The old French expression, goût de terroir, is often mistakenly translated as “taste of the soil.” Two noted scholars in Burgundy, Sylvain Pitiot and Pierre Poupon, explain that it was intended to convey any and all site-specific characteristics – and not minerals in particular.

As Van Leeuwen has observed, “terroir is pluri-disciplinary.” Taking up where Gérard Seguin left off, Van Leeuwen speaks of terroir as a “cultivated ecosystem.” He points out the historical dimension and the importance of human factors, because “terroir is managed.” This far-reaching view is in fact not new. The language of the legislation of France’s Appellation d’Origine Contrôlée refers to both place and people. An appellation is a geographic milieu whose quality or characteristics is determined by natural and human factors, as outlined by Pitiot and Poupon. It is clear from this that terroir, rightly seen as the foundation of controlled appellations, was long considered dependent on more than the environment alone. In reality, place and process – or, if you will, nature and nurture – are interwoven in a symbiotic relationship: wine as we know it would not exist without the purposeful intervention of human beings.

Van Leeuwen also believes science can serve not simply to explain terroir, but also to enhance its management. Environmental factors such as soil and climate, he says, need to be expressed in quantifiable terms; to wit, water, temperature and light. In recent years, tools have been devised to “measure and map terroir factors”: small-scale weather stations along with techniques to assess vine water and nitrogen status. Air temperature, a critical variable, can be studied at multiple levels: macro, meso and micro. Ultimately, the resulting data allow the expression of terroir to be optimized. Hence, while terroir is often seen as immutable, modern technology permits wine growers to amplify the particularities of a specific vineyard through the selection of vines or rootstocks as well as other management strategies. This signals that we have entered a new phase in our understanding of terroir.

Terroir has been largely embraced in its all-encompassing sense by wine growers around the world. There are still a few naysayers. Mark A. Matthews, a plant physiologist at University of California-Davis, makes his views obvious in the title of a recent book, Terroir and Other Myths of Winegrowing. Matthews presents lucid analysis of several truisms including the prevalent belief that high yield equals low quality. His critique of terroir is less compelling and seems to miss the fundamentals laid out by Van Leeuwen and others. He argues that “terroir and goût de terroir became a soil-based explanation for why some producers enjoy a reputation for the best, rather than the lowliest products.” He is right that terroir was and is used as a marketing device, but that ignores its larger meaning. Stripped of commercial motives, terroir is simply a conceptual model and is not automatically synonymous with high quality. Matthews also maintains “there is no consensus on terroir,” adding that “it conveys no useful information about the vineyard.” While this is an overstatement on both counts at the very least, he accurately portrays real-world disagreement about the word’s definition. At the same time, his narrow view seems out of date and fails to account for work by his academic peers, who are bringing scientific rigor to the comprehension of terroir.

Terroir, at its origin a rather simple idea of a plot of land suitable for farming, has become a tangled and often contentious topic. For several decades, scholars have been studying the roles of climate, soil and other natural features in shaping wine character. The analysis is complicated by the human component; that is, the cultivation of the vineyard and the production techniques. Fundamentally, we know terroir exists because educated tasters, working in “blind” conditions, can identify the origin of wines owing to distinctive signatures, both natural and cultural. Now, the entire discussion is moving forward thanks to new thinking and technology serving to confirm the value of terroir as a practical framework.