by Dwight Furrow
Few terms in the wine world are more controversial than “terroir”, the French word meaning “of the soil”. “Terroir” refers to the influence of soil and climate on the wine in your glass. But the meaning of “terroir” is not restricted to a technical discussion of soil structure or the influence of climate. Part of the romance of wine is that it (allegedly) expresses the particular character of a region and perhaps its people as well.
According to some “terroirists”, when we drink wine that expresses terroir, we feel connected to a particular plot of land and its unique characteristics, and by extension, its inhabitants, their struggles, achievements, and sensibility. Can't you just feel their spirit coursing through your veins on a wild alcohol ride? The most extreme terroirists claim that the influence of soil and climate can be quite literally tasted in the wine. If this strikes you as a bit of, well, the digested plant food of bovines to put it politely, you are not alone. Many in the wine business are skeptical about the existence of terroir claiming that winemakers should make the best wine they can without trying to preserve some mystical connection with the soil. But the issue is an important one because the reputation of entire wine regions rests on the alleged unique characteristics of their terroir, not to mention the fact that the skill and discernment of wine tasters often involves recognizing these characteristics.
There is confusion, however, regarding what this concept of terroir conveys. Some uses of the term simply imply that wine grapes are influenced by climate and soil so that wines from a region with broadly similar soil types and macroclimates have common characteristics discernable in the wine. This is obviously true and unobjectionable. Factors such as the ability of soil to drain or absorb water, the presence of stones that radiate heat into the vineyard, and the effects of nutrients on plant metabolism are among the important known effects of soil on vineyards. The soil and climate in Bordeaux differs from the soil and climate in Burgundy and thus they grow different grapes and make wines of quite contrasting styles that are apparent in the glass.
But the vociferous defenders of terroir have something more controversial in mind. They claim that the distinctive character of the soil is directly transferred to the glass. As Matt Kramer writes in his book Making Sense of Wine, some wines “… allow us to eavesdrop on the murmurings of the earth.” One chardonnay is described as exhibiting “a powerful flavor of the soil: the limestone speaks.” This is a much more controversial claim because Kramer and others seem to be suggesting that there is some discernable likeness between the taste of the wine and the taste of the soil. If this strikes you as disgusting, you are not alone, especially when a wine is reputed to exhibit barnyard notes. They ought to be honest and label their wines Domaine de Poop. In fact, it is usually flavors of chalk, flint, or slate that is reputed to be in the wine, and the view that such a flavor likeness exists is widely held especially in France, Italy, and Germany.
Science has weighed in on the controversy, and the science seems to be on the side of the anti-terroirists. Science writer and wine expert Jamie Goode in a series of articles on this topic writes:
“But I'd exclude from my definition of terroir the concept that soils can directly influence the character of a wine, for instance, by flavour compounds in the soil being directly translocated to the grapes. This sort of mechanism is not impossible, but it does seem to be hugely implausible. I'm not a root physiologist, but I do have a PhD in plant biology, and I've yet to hear a convincing explanation for how soil components can directly alter the flavour of grapes and hence the finished wine… Suffice to say, stony, earthy or mineral flavours in a wine are not necessarily 'terroir' notes. If a wine grown on chalky soil tastes chalky, it's an unjustified leap of faith to say that this is the 'terroir' speaking. The minerals in the soil may be fortuitously imparting chalky notes to the wine indirectly by altering the vine's metabolism, but you'd only be able to tell this by comparing this wine with one made from the same grapes grown on different soils and vinified in a similar way.”
Food scientist Harold McGee, writing, with Daniel Patterson, in the New York Times agrees:
“What about the flavors of soil and granite and limestone that wine experts describe as minerality – a term oddly missing from most formal treatises on wine flavor? Do they really go straight from the earth to the wine to the discerning palate?
Consider the grapevine growing in the earth. It takes in elemental, inert materials from the planet – air and water and minerals – and, using energy captured from sunlight, turns them into a living, growing organism. It doesn't just accumulate the earth's materials. It transforms them into the sugars, acids, aromas, tannins, pigments and dozens of other molecules that make grapes and wine delicious.”
The science suggests that minerals are dissolved in soil moisture which is absorbed by the plant and influences the development of the grape vines. The minerals have no direct influence on flavor.
But here is where this debate gets muddled. Nothing in these referenced articles on the science of terroir deny that the unique characteristics of a region's soil can, with the proper vinification, influence the taste of the wine. In fact they repeatedly assert the plausibility of an indirect connection between soil and flavor, although the mechanisms have not yet been discovered. As McGee and Patterson write:
“It's possible, then, that soil minerals may affect wine flavor indirectly, by reacting with other grape and yeast substances that produce flavor and tactile sensations, or by altering the production of flavor compounds as the grape matures on the vine.
It seems to me this concedes everything the terroirists want. If the soil uniquely alters the grapes' metabolism in a way that influences flavor in the glass, then the flavor is a result of the soil, and the wine is an expression of those unique properties. The upshot of the science is that flavors in the wine are not copies or imitations, or likenesses of the way these minerals taste in the ground. But why anyone should care about that is beyond me. (I have yet to talk to anyone who makes a habit of tasting rocks. But if you are so inclined let me know the results.) What should matter to terroirists are the causal influences of unique factors in the soil of particular vineyards on the discernable flavors of wines from those vineyards. If such a connection exists, regardless of how direct it is, their claims to the uniqueness and special value of place-“somewhereness” as Matt Kramer puts it-will have been vindicated. Furthermore, the vindication suffers no loss of romance. For it is still true that centuries of careful husbandry and the matching of grapes and soil by dedicated viticulturalists have produced unique wines of extraordinary beauty that cannot be replicated elsewhere.
On the other hand, why should skeptics deny the possibility of such an indirect connection? Since we are talking about the causal influence of soil constituents on the metabolism of grapes, there is nothing mystical here. The terroirists seems to want more than they need and the skeptics (at least those whose skepticism is grounded in science) deny more than they must. There is plenty of room for agreement here with no compromise of basic principles.
So I will unilaterally declare a truce in the “terroir wars”. Who says philosophy has no influence on worldly events?
For more ruminations on the philosophy of food and wine visit Edible Arts.