In the first series of my articles on Tasting Terms, I discussed the meaning of the words we use to describe how wines smell and taste. Here in Wine Structure and Texture I, we get into structure and texture, which is something of a different game.

When we talk about structure and texture in wine, we move our descriptions of the stuff into somewhat more creative territory. Where flavor and appearance are concerned, there is more or less general agreement as to what a raspberry tastes like or what a ruby looks like, but when a writer says that a wine is tight or expansive on the palate, he’s asking for a little imaginative input from the reader. And it’s here that things can sometimes get a little confusing, because we’ve moved from descriptions of tastes like and looks like to descriptions of how something feels, which is even more subjective.

A good beginning point to getting a grip (pun intended, as you’ll see later) on structure, is to remember that a typical wine is made up of 80-85% water. If we consider water to be basically neutral where our tactile impressions of wine are concerned, then we’ve just made our jobs slightly easier, since we only have to look at what remains of the wine’s composition. That remaining 15-20% is where we find the alcohol, tannin, acid, sugars, and so forth. It’s these components that give wine structure and texture, and it’s the way they make our mouths feel that we attempt to describe.

##The Components## Before launching into the structure/texture lingo, let’s look at those specific components:

Alcohol– The most basic product of fermentation. Although the specific gravity of alcohol is lower than that of water, alcohol has a somewhat viscous texture and contributes greatly to a wine’s body. As a result, wines with high alcohol content will generally feel fuller bodied than those with low alcohol.

Tannin– Tannins are bitter tasting, complex compounds that are extracted from grape skins, seeds and stems during and following fermentation. The most notable tactile effect of tannins is that they are very astringent, and tannic wines tend to leave a somewhat fuzzy feeling on your teeth. Some tannins are also pigments, so it’s sometimes, but not always, the case that very dark wines are also tannic. Tannins also contribute significantly to the ageability of wine (along with alcohol, sugar and acidity), and it’s for this reason that red wine generally lasts longer than white wine: whites have very little, and sometimes no, tannin. Because of the astringency of tannins, they generally lend delineation to a wine’s structure, balancing the viscous effects of alcohol and other compounds.

Acidity– The component that lends tartness to wine. In the mouth, acidity is usually felt first in the cheeks, and a good way to feel the difference between tannin and acidity is to note where in the mouth you notice their effects: tannins give you fuzzy teeth, acidity gives you squeaky cheeks. Like tannin, acidity gives wine delineation, balancing alcohol and sugar. Acidity also cuts through fats and oils in the mouth (which we’ll get to when we discuss food-friendliness) and tends to result in wines with very clean finishes (which we’ll get to later, as well).

Sweetness– Sugar has a similar effect to alcohol on a wine’s body, giving the wine a somewhat more viscous feel in the mouth. In good sweet wines, the sugar is usually balanced by acidity and/or tannin. Sweetness is a fairly obvious characteristic of wines, but it’s really not as easily detected as many drinkers think; many popular wines that are thought to be dry actually contain a fair amount of residual sugar, which is masked by acidity, tannin, or other components.