This is a difficult question, because there’s no one answer. It’s a French term, with no direct English translation and, if you look it up online, you’ll notice that no one agrees on what it encompasses.
Jamie Goode, of Wine Anorak, captures the spirit of it very well by saying “… it can probably best be summed-up as the possession by a wine of a sense of place, or ‘somewhereness’. That is, a wine from a particular patch of ground expresses characteristics related to the physical environment in which the grapes are grown.”
Macro vs. micro
On a grand scale, you could say that terroir – differences in soil, topography and climate – is the reason that Cabernet Sauvignon from the Medoc doesn’t taste the same as Cabernet from Napa Valley. The Burgundians are well known for going by the meter when it comes to differences in terroir and this narrower situation is the more common application of the word. On our 9.5-acre site, here at the winery, we see differences in character from the Cabernet that’s harvested in front of the winery and the Cabernet that grows behind it, several yards away, and we attribute that to differences in the soil, which we have studied carefully. So, in Mr. Goode’s words, we’re experiencing “…site-specific differences in wines that are caused by factors such as soil types, drainage, local microclimate and sun exposure – some sort of link to geography.”
Purists say that terroir has only to do with the soil. That’s a pretty small group. Far more people believe that terroir takes in a combination of soil, climate, topography and exposure. And, a few go on to include the intervention of man – the vineyard manager’s choice of rootstock or decision to pull leaves or thin the crop.
Where does it come from?
We know that soil can’t directly flavor the grapes. If it could, as Dr. Mark Matthews of UC Davis explained to the New York Times, they’d “…taste like dirt. Any minerals from the solid rock that vine roots do absorb have to be dissolved first in the soil moisture. Most of them are essential nutrients, and they mainly affect how well the plant as a whole grows.” This can mean depth, richness, water-holding capacity, etc, and perhaps all of those factors alter the production of flavor compounds, as the grapes ripen, and have an indirect influence on the character of the finished wine.
Of course, all of this has nothing to do with winemaking, which is interesting because some of our most technically-astute enologists believe that we mistakenly identify sulfur compounds, which may be the result of fermentations with nutrient deficiencies, as “terroir” flavors or mineral characteristics.
Does marketing play a role?
The Europeans are very terroir oriented, in fact it’s the basis for the way their wines are classified. In most cases, instead of naming the wine for the variety that makes it, it’s named for the place it comes from and there are local regulations regarding which varieties may be grown for commercial purposes. Presumably, these are the varieties that have done well there, historically, and have come to represent the region. Could other varieties do well in the same region? Of course they could, but they’re looking for regional “typicity” in their wines.
We should add that there are those who believe the concept of terroir is just a marketing ruse because the term is so frequently abused as a marketing enticement. But, anyone who’s an experienced taster of wines from around the world is likely to say that terroir is real because it’s demonstrated in the aroma and flavor. The terroir imprints the fruit, and wine, with certain characteristics that can be identified by tasting, even if it doesn’t show up in the lab work.
We’ll never have “the” answer because it’s too complicated. There are so many variables involved in winemaking that are independent of the terroir, that it’s almost impossible to sort it all out. One thing we know for certain is that if a winemaker is blessed with exemplary fruit, he can still manage to produce plonk. And, if presented with average-quality grapes even a wine wunderkind, employing all his wizardry, can’t hope to make anything better than ordinary wine. So, great wine has always been the result of close collaboration between man and nature and the debate about the role of terroir will continue.