Have you ever pulled an anticipated bottle up from the cellar only to encounter that telltale whiff of vinegar or nail-polish remover that indicates volatile acidity run rampant? Did you have more bottles? And if so, did you find them just as tart?
Volatile acidity, commonly referred to as "VA," is a catch-all term for all of the acids present in wine and how we perceive them, but the key offender is acetic acid, which is the product of a bacteria known as Acetobacter aceti. With the help of oxygen, acetobacter converts sugar and alcohol into acetic acid, which is why it's the most important component of a mother of vinegar, but not necessarily something you want in your wine.
In small measures—most wines have less than 400 mg/L of acetic acid; the human threshold for detecting it is about 600 to 900 mg/L—volatile acidity imparts a racy, balsamic edge to a wine. It's also likely to be present anytime you see "high-toned" fruit flavors in a tasting note. It can offer a tangy edge that works well with dishes that could use a little oomph, say pastas with red sauces. It stretches the flavors, and some vintners encourage a touch of VA to do just that.
But I hate to open up one of my wines and find elevated levels of VA: It's a flaw for me. And I would expect other bottles of the same wine to have the same character, and more time in the bottle will typically only exacerbate the problem.
When I come across a wine that's lifted, I'll decant it in hopes that the sharp aromas will blow off. If I'm hosting a dinner party, I share the wine anyway, but I'll always mention what I consider the wine's strengths and weaknesses, and when it comes to VA, that's a flaw, regardless of how many pick up on it.