How do I know if a wine is "corked"? And what recourse is available if it is?

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,
I hear a lot about what are called “corky” wines. What are “corky” wines like? What can you do if you have one?
—Patranun L., Bangkok, Thailand
Dear Patranun,
When someone describes a wine as “corky” or “corked,” that means the wine is suffering from the musty, dank-smelling compound known as TCA, or 2,4,6-trichloroanisole. It’s caused by the interaction of mold, chlorine and phenols (organic compounds found in all plants). It can develop in corks themselves, which is why TCA is linked to corks, hence the “corky” or “corked” term, but it can originate in other places, like cardboard cases or wooden pallets.
I usually find it easy to pick out TCA odors in a wine, because they are so distinctive, just like the smell of old books or wet cement. Sometimes it becomes more apparent when the wine has a chance to breathe. When I’ve (mistakenly!) tasted a wine with TCA, that musty quality overwhelms the flavor of the wine, and it often leaves a gritty, aspirinlike taste in my mouth.
What can you do if you have a corky wine? The ritual of tasting a wine at a restaurant before being served a bottle is there for this purpose—if you think you have a corky wine, speak up. If it’s from a bottle of wine you purchased at retail or from a producer, you can try to return it, but you’ll probably need a copy of your receipt, and they might ask you to return the opened bottle as well.
—Dr. Vinny