4 Ways to Tell if a Wine Has Gone Bad

One of the most common questions we get on our Tuscan wine tours is about how to tell when a wine has gone bad. Suppose you’re looking forward to a nice glass of wine, but something about it tastes off.  Does this mean you have to pour it down the drain?

Fortunately, this doesn’t happen very often with unopened bottles of wine.  But once you pop the cork, it can go downhill fairly quickly.

Either way, here’s how you can determine if a wine has gone bad.

How to tell if a wine has gone bad:

Inspect the cork

A wine is said to be “corked” if, at some point, the cork had mold growing on it.  This leaves a chemical known as TCA in the cork and a bad flavor in the wine.  Although you’ll also want to check the wine, if you notice that the cork smells like a wet dog or dank basement, this is a sign of cork taint.

Take a look at the cork before opening the bottle. If the cork is pushing up past the rim of the bottle, the wine may have been overheated at some point, making it taste duller than it should.

Check the wine’s color

The main reason a wine goes bad is that you didn’t drink it fast enough.  This isn’t usually a problem with flavorful Tuscan wines!

Once a wine is opened and exposed to oxygen, chemical changes start to occur.  A wine will start to brown like an apple does when you cut it open.  Since some wines are tawny-colored to start with, the main thing to look for is a change in the color.  For example, the Sangiovese grapes that are used to make Chianti wines typically give them a ruby red color.  If the color looks dull and brownish, your wine may have been open too long.

Smell the wine for signs it’s gone bad

If a wine has been exposed to the air too long, the fruity aromas disappear and it will begin to have a sharp smell.  A strong vinegar smell means the wine is past its prime.

You’ll also notice the wet dog smell in a wine that has been corked.  If it smells more like a wet horse or band-aids, those are signs of a bacteria caused by spoiled yeast.

Taste the wine

Finally, you can confirm that a wine is bad by tasting it.  This won’t hurt you, although you won’t want to drink very much.  A wine that has been open too long will not only smell like vinegar, you’ll notice it in the taste. It may even cause a tingle in your nasal passages like horseradish does.

How can you avoid this?  They key is to minimize exposure to oxygen once you open the wine.  There are many gadgets for this or you can decant the wine into a smaller container. Of course, the best solution is to drink the whole bottle.  Salute!

Want to learn more about wine when you visit Tuscany (and taste some too)?  Sign up for one of our Florence wine tours or for a class at the Florence wine school.