Alcohol in wine

Alcohol in wine is as important an element in the final product as the grape itself. It doesn’t just effect how you feel after drinking it. It effects the taste, texture, and structure of the wine itself.
Alcoholic strength is the ethanol (the main product of fermentation) in wine. It is measured in percentage as opposed to proof, which is how alcohol is measured in hard liquor. In the U.S., if the wine is designated as a “Table Wine” on the label, it must have less than 14% alcohol by volume. The law also permits a 1.5% leeway. If a label says 12.5% alcohol by volume, it can actually be as high as 14% or as low at 11%. In the U.S., if a label simply says “Table Wine” then the alcohol content is between 11% and 14%. In Europe the variance is between 8.5% and 14%.

These numbers were arrived at because most grapes after fermentation come in somewhere between 8% in alcohol by volume on the low end, and 14% on the high end. But, that was some time ago. Today wines can come in much higher, especially in hot climates like Australia. And, with new viticulture techniques, and greater controls in the winemaking process, it is not unusual to see wine over 15% in alcohol. There are some Zinfandels and Syrahs, the heavy hitter grapes, that can go up to 16.5 in alcohol by volume, which is huge. Obviously, the “Table Wine” designation is not on their label.

The breakdown, approximately is:
Table wine: 8 – 14%
Sparkling wine: 8 – 12%
Fortified wine: 17 – 22%

Fortified wine is wine that has been strengthened with the addition of alcohol. Wines that fall into that category are dessert wines, Sherry or Port. Alcohol has a huge effect on how a wine tastes and feels in the mouth. In table wine, i.e. wine that has gotten its alcohol content from the fermentation of grapes alone, alcohol contributes a sweetness.
It can also be perceived as bitter, especially in a white wine with little flavor and high alcohol. In the mouth, it has a warm feeling. Too much alcohol, and it can have a hot feeling. It adds thickness to the wine. When someone refers to the “legs” in a glass of wine, which is the residue of wine running back into the body of wine after tilting the glass, this is partially determined by the alcohol content of the wine. Swirl some wine in a glass and watch it settle. Look at its legs. Legs are a desirable thing in wine.
And last but not least, the alcohol content in wine can greatly affect the drinker. Having a glass of wine at lunch can greatly affect the rest of your day. Try a wine with 11% alcohol content one day. The next day try one with 14% and feel the difference. In Europe the quaffing of bottles of Chianti or Vin de pays at lunch is not generally of the 14% variety, but of the 11% and lighter variety, which is why they can go back to work after lunch…sometimes.