Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.
Dear Dr. Vinny,
Why do most wines seem to be about 14 percent alcohol?
—Rob, Lexington, Ky.
I took a look through our records, and the wines we taste can range from as low as 5 percent alcohol (some wonderful Hungarian Tokaji dessert wines) to as high as 22 percent (for fortified wines like Sherry).
You’re correct that the vast majority of wines check in (at least on their wine labels, which allow for a variance) at around 12 to 14 percent. The biggest factor that determines the alcohol percentage in a wine is the sugar in the grapes, which is converted to alcohol during fermentation. Grapes, like all fruits, can only get so ripe before they spoil. The type of grape, climate and weather, harvest decisions, yeasts and fermentation processes can all influence the level of alcohol in the finished product, but it’s still a relatively small window.
One way a wine can end up with a higher alcohol is if it's fortified by the addition of brandy or another neutral spirit. The spirit can be added at or near the beginning of fermentation (as in France’s vin doux naturel), during fermentation (as in Port) or after fermentation (as in Sherry).