We can't really talk seriously about wine without bumping into the notion of terroir, that French concept of place reflected in the glass. I am more concerned about making sure we're all talking about the same thing when we use the word.
Actually tasting the effects of terroir in a wine can be problematic. This elusiveness makes cynics wave off the idea as nothing but a marketing ploy by French vintners looking for an edge. Although that does happen, I do believe terroir applies not just in France but anywhere in the world serious efforts go into the wine.
We often can't agree on what the word means, however. For some of us, myself included, it comprises all the physical elements of a place that can affect the character of wine made from it. To others it's a specific character, or a cluster of characteristics, they expect to find in the wine at hand, even if introduced by the winemaker.
In other words, is terroir about the basic material, or how it expresses itself in the wine?
For me, terroir covers the sum total of a site's constants, including soil composition, latitude, elevation, contour, sun exposure and climate (but not vintage, as that changes every year). It does not include vine training, irrigation, leaf pulling or anything else that humans might do, especially anything that happens after the grapes are picked. It's important to separate what Mother Nature gives us from how we transform it into wine.
Is grape variety part of terroir? I say no, but certain grape types will certainly express a specific terroir better than others. In Burgundy, Pinot Noir does this much better than Gamay, and better in Burgundy than it would in the warm vastness of Provence. Yes, terroir can apply to a village or a region, not just a single vineyard. Most of us certainly can cite the different characteristics we expect from a comparison of, say, Chambolle-Musigny with Nuits-St.-Georges, or Burgundy with Russian River Valley.
Winemaking? Not part of terroir, although a winemaker's every choice affects its expression in the finished wine. How and when to crush and press the grapes. How much to press. Ferment in stainless steel, concrete, wood or something else? Temperature and length of time in contact with the skins. Punch-downs or pump-overs? Barrels or larger containers for aging? New barrels or old? How long to age before bottling? Those are just a few options that will significantly affect the character of the finished wine. Within a region, most winemakers might favor certain of these choices over other options. In some European appellations, these questions are precisely defined by law.
If it's common for people to do things a certain way in a village or region, that can become what seems to be a constant characteristic of the wines from there. Some want to include "the work of man" in their definition of terroir. But that's regional style, not an expression of terroir.
We use terroir too loosely. We refer to a specific vineyard as "a terroir," although the French correctly employ a different word, climat. We say a wine has goût de terroir, a French term for tastes we expect to find in a wine made from a specific place. Too often it's misused as a synonym for earthy notes. But it can be anything—fruitiness, spice, savory notes, tannin qualities, to name a few.
Every wine reflects terroir. Some do it by amplifying specific characteristics possible from a single vineyard. Others make interesting wines by blending several vineyards within a larger area, playing the strengths of one against others' weaknesses, hoping for a more compelling wine that still reflects the region. Some wines may be missing something on their own, but blended with others can make a lovely wine when their assets and deficits combine to best advantage. This is an example of a winemaker using terroir subtlely.
Books that address terroir seldom make the connection between site and what characteristics it produces in wine. They go on and on about the soil, and the slope, and exposure, but don't always relate it to what's in the glass. That's probably because it's so difficult to tease out these elements from all the rest, as we struggle to describe a wine.
Terroir is a useful and meaningful idea. Let's just try to be clear about what we intend to say when we wield it.