What is “dry” wine? Aren’t all wines wet …?

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,
What is “dry” wine? Aren’t all wines wet …?
—Bob, Port Orchard, Wash.
Dear Bob,
I don’t mean to blow your mind but … all wines are wet, but many of them are also “dry.”
“Dry” can be a confusing term in wine because it has two meanings (neither of which are a reference to whether or not the wine is in liquid form). The first is a bit of a technical term, and here the opposite of dry is not wet, but sweet. Fermentation is the process that converts sugar into alcohol, in this case, the sugar in the juice of ripe grapes. When all the perceptible sugar in a wine is converted to alcohol, it is considered “dry.”
Most people don’t carry around hydrometers to measure the technical sugar level of a wine, but most table wines are “dry.” When someone says they like or don’t like “dry” wines, I usually don’t assume it necessarily has anything to do with the amount of residual sugar, but more about the way it tastes. Dry wines won’t necessarily dry out your mouth—they’re just not sweet (another oft-misused term that some people confuse with “fruity”).
This is where the other use of “dry” comes in: It’s about the perception of dryness, or how a wine feels in your mouth. Even though wine is a liquid, it also contains tannins, which can elicit a drying sensation in your cheeks and palate if they’re out of balance with the wine’s alcohol, acidity and residual sugar. Some dry wines can indeed give you cottonmouth, or a more subtle tugging sensation in your cheeks similar to that of a strong cup of coffee or tea (both of which also contain tannins).
When describing wines, it’s helpful to not just describe the flavors and aromas, but also the textures, the structure and how the wine feels in your mouth. Is it velvety, juicy or chewy? A technically dry wine can show in all of these ways, and more.
“Dry” is not a negative descriptor, and dry wines aren’t the opposite of fruity wines. A firm, structured wine can still have plenty of ripe, fresh fruit flavors. And don’t get tripped up by sweet-smelling aromas that might be a result of a wine aging in new oak barrels: Just because a wine might smell like caramel, vanilla or cream soda doesn’t mean that the wine is “sweet.”
—Dr. Vinny