Wine Basics 102
© by John Juergens
Astringency actually is a tactile sensation as opposed to a taste or smell. The best way to describe astringency is a dry, puckery sensation on the surfaces of the tongue and lining of the mouth. If you have ever cracked open a pecan or a walnut and accidentally got a piece of the hull in with the meat of the nut, you know what I mean by dry and puckery. The same group of chemicals in both nuts and grapes cause this effect, that is, the tannins.
Tannins are a group of compounds found in all sorts of plant material. In grapes tannins can be found in the stems, seeds and skins. Depending on how the grapes are handled during the wine making process determines how much of these tannins are transferred to the final product. One of the few near absolutes in wine making is that you do not want much tannin in white wines and you need to have a fair amount in red wines in order to have a well-balanced wine. The reason for this is that tannins can impart a harsh bitter quality to white wines, and red wines need a certain amount of tannin to balance other components that tend to make red wines very soft. It is similar to the effect you get with too little acid; the wine becomes soft and flabby. Wine makers describe tannins as providing a certain structure or "backbone" in red wines.
The other main wine characteristic is body. These days everyone seems to be searching for great body, even in their wines. Body is the way the wine feels in your mouth. As with astringency, this is another tactile sensation. The best way I can describe this is to think about the difference in how plain water and whole milk feel in your mouth. Water is kind of just there. Milk, on the other hand, has a certain weight to it and it coats the surfaces of the tongue and mouth. Unless you are drinking deuterium, we donít think of water as having any particular weight to it. However, wine has a lot of stuff dissolved in it that contributes to the weight or body: sugars, flavanoids, alcohol, etc. In fact, over 400 different compounds have been identified in red wine, and we are still counting.
So how do you turn this new knowledge to practical use when you are in the wine shop? White wines first. Right off the bat, you can forget about tannins and astringency since almost all white wines have tannin levels too low to detect by sensory means. That leaves you with sugar, acid, and body to figure out. As I mentioned in my Basics 101 article, you simply have to memorize or keep a list of the major characteristics associated with the various types of wine.
Fortunately, there are a couple of other clues you can look for on the label. For example, we know that a Sauvignon Blanc wine most likely with be fairly dry (i.e. not sweet) and it probably has a fair amount of acidity or crispness. To help divine the body, check the alcohol content. Lighter bodied wines frequently have a lower alcohol content, that is, below 12%. You can also check the color of the wine if it is in a clear bottle. As a rule of thumb, for dry white wines the lighter the color, the lighter the wine.
You can get another clue from the country of origin. Generally, wines from Europe tend to be lighter and seem a bit leaner than wines from the New World countries such as the U.S., South American, and Australia, which can seem robust and almost chewy by comparison. European style wines, however, also tend to be more delicate and possess more complexity in the flavors and aromas.
The final clue for deducing body is price. There is no mystery here. The best fruit produces the best wine with the best body. Lower quality fruit usually produces a wine with less body (unless it has been manipulated in some manner). Good fruit costs more than fruit of lesser quality. Itís that simple.
When we are talking about red wine all of the above applies, but now we have to throw in another dimension. The tannins contribute significantly to the mouth feel of a wine. The bad news is that at present there is almost no way to know with a high degree of certainty how much tannin is contained in any particular wine. However, there are some rules of thumb to go by here as well, but there are significant variations to the rule.
In general, the lighter in color a wine, the less tannin it will have. The reason for this is that color pigments are contained in the skins of the grape along with tannins. All wines start out as clear or "white" juice. The longer the skins remain in contact with the grape juice, the darker the wine and the more astringent it can become due to extracted tannins. See? Itís all connected!
But, wait. We also have to consider that different types of grapes contain different amounts of tannins in their skins and seeds. Therefore, it is possible to have a wine that is somewhat light in color, but higher in tannins, and vice versa.
The perfect example of this is the difference between Cabernet Sauvignon and Merlot grapes. Both grapes produce dark, inky wines, but, while the Cabernet can have enough tannin to cure animal hides, the Merlot usually is soft and mellow due to low tannins. This is the primary reason for the huge popularity of Merlot. In fact, in most parts of the world Merlot traditionally has been used as a blending grape to soften up the rough edges of the Cabernet grape, which consistently produces a far better wine than Merlot.
There is one final consideration. I mentioned above that red wines with low levels of tannins can result in a soft, flabby wine as you get with too little acid. The point I want to make is that it is easy to confuse the effects of acid and the tannins since they have somewhat overlapping sensations. In the drinkable range, tannins produce a purely tactile sensation, and acid can produce both a tactile effect and a taste sensation. In almost every case when you get a puckery sensation from a white wine, it will be due to the acid. But with red wines sorting out the effects of acid and tannins can be a lot more difficult.
Hereís a practical exercise to train yourself how to recognize the difference between acidity and astringency. Get out your trusty lemon again, suck out some of the juice, and let it coat the inside of your mouth and then swallow it. Notice that you get the puckery sensation and an astringent-like feeling on the sides of your mouth. It is important to notice where these sensations occur on your tongue. It should be on the sides and maybe toward the front. Also notice that the lemon juice causes you to salivate, just like those torturously sour candies kids are eating today.
After you completely recover from that acidic jolt, take some kind of nut that has a thin hull, such as a pecan, Spanish peanuts, or a seed from a table grape. Chew it up thoroughly and let the moosh come in contact with your tongue and sides of your mouth before you swallow it. Donít worry about swallowing the grape seed. Itís supposed to be good for you. Now notice the nature and location of the dry, puckery sensation. It will tend to be on the sides of your mouth and around your gums and on the back of your tongue. Notice also that the tannins donít cause increase salivation and your first reaction is to get something to wash that stuff out of your mouth. Now try it with a red and white wine to see if you can detect the same effects. Remember, you have to practice, practice, practice.
My wine picks of the week are: red Ė Cline Red Zinfandel; white Ė B&G Vouvray