Balance is perhaps the most sought after quality in a wine. When you ask winemakers what they are trying to do, the common answer might best be paraphrased as “to express the vineyard in a balanced wine.” But what is balance? Somewhat like pornography, you know it when you see it, but it’s awfully hard to define.
The most common occurrence in which you hear balance evoked as a descriptor is in the context of alcohol. Complaints about high alcohol are usually met with the rejoinder, “but the wine is balanced, so why is it a problem?” This is and isn’t true.
I would say that alcohol was balanced in a wine when it is not noticeable. Lack of balance most often takes the form of a perceptible feeling of heat on the finish. While this occurs most often in wines with high alcohol, I’ve had wines with alcohol over 14% where it was not evident and I’ve had wines at 12.5% where alcohol was obtrusive. I have been puzzling over what it is that confers balance.
I think the most common mistake that producers make is to believe that because a wine is balanced with regards to alcohol, acidity, tannins, all the obvious factors, that’s the end of the argument. But isn’t it true that a wine with 12.5% alcohol needs a different balance overall than a wine with 14% alcohol? If you added 1.5% alcohol to a 12.5% alcohol wine, the effect would be pretty noticeable. The limit of chaptalization to 2% potential alcohol (now reduced to 1.5%) in the northern areas of Europe was intended to stop the wines coming out of balance.
Different grape varieties accumulate sugar at different rates, and certainly the varieties grown in warm climates have always reached high sugar levels at ripeness. High alcohol has always been part of the character of wines such as Chateauneuf du Pape or Barolo or Rioja. But with varieties originating in cooler climates, take for example Cabernet Sauvignon in Bordeaux or even Napa, or Pinot Noir from Burgundy, the alcohol has shot up in the past two decades. The reason is that the grapes have been picked at much higher levels of ripeness. Yes, the wines are balanced, but the balance is different: overall it is richer, more extracted, there is more (but riper) tannin; you need all this to balance the alcohol. (Of course, I’m referring specifically to dry table wines here: fortified wines such as Sherry or Port are another kettle of fish, to mix a metaphor.)
The change in extraction is surely just as responsible as alcohol for the change in the character of Bordeaux and Burgundy over the past two decades: people talk about the alcohol levels, which have increased about 1.0-1.5%, but the richness has increased more than that because some of the alcohol in the older wines came from addition of sugar before fermentation. The change in style over the past three decades is equivalent roughly to a 3% increase in potential alcohol. In North America, as typified by Napa, the increase as been around 2% in potential alcohol (here sometimes hidden by the use of alcohol reduction techniques).
Come to think of it, perhaps there are more similarities than just the difficulty of description between questions of balance and pornography. Wines that have high alcohol, even when balanced, tend to have a titillating effect on the palate: after a small taste that fills the senses, you try for more. But the wine rapidly becomes fatiguing. I suspect that the issue may be the level of dry extract. A wine with 14% alcohol is more powerful not just because of the alcohol but because of the total level of extraction, and I think this is what makes the wines so attractive at first blush, but fatiguing afterwards. They show well at tastings, but I like to perform a reality check by having a bottle for dinner: my measure of a great bottle is that when it’s finished I would in principle like to have another; but when it’s delicious to begin with but I tire of it half way through, I have to concede I was fooled at the tasting. That’s my real measure of balance.
This make so much sense in that many wines from poor years are chaptalized and have undeveloped tannins and fruit, as they drop the tannins and the alcohol starts to show and unbalances the wine. Balance is a personal thing, I look at the acid to tannins then fruit and as you noted alcohol is only out of balance if it is obviously too high or low.