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 left a case of wine in my car for a day when the temperature was in the upper 80s F. The bottles were very warm when I removed them, and the tops looked like Champagne bottles. Did I kill them in the heat?
—Jeanne, Hudson, Fla.
I’m cringing as I type this, because it doesn’t sound good. When a wine gets hot, the liquid inside expands, and the only place it can go is out, placing pressure on the cork or seeping past it. And your wine likely got much hotter than the upper 80s: According the Centers for Disease Control, when it's more than 80° F outside, the temperature inside a car can easily reach more than 150° F. If your corks have pushed out—which is what I’m guessing you’re describing by saying they look like Champagne corks—your wine almost certainly got too hot. A sticky residue of wine on the outside of the cork is another sign of heat damage.
This is bad for two reasons. First, if a wine is exposed to that much heat, the flavors can become “cooked,” which is pretty much what it sounds like: The wine’s fresh fruit flavors are replaced by stewed or baked notes. There’s no formula for how long it takes for this to happen, but that long a time in that much heat is probably enough to do it. Second, if the cork expands and contracts, that process can let oxygen into the bottle, and that means the wines will start aging prematurely, taking on nutty and bruised apple notes.
There’s not much good news, except that it won’t make you ill to try the wines, and that sometimes a wine can still be drinkable or even enjoyable despite all of these signs. The only way to know for sure is to pop some corks and taste for yourself. Good luck!