Last time we looked at how a wine can turn brown and take on a nutty sherry-like flavor. That’s oxidation which is just one of several ways in which a wine can go bad.

There are several other common wine flaws. So, let’s take a quick look at each.

TCA — This is a powerful chemical that even in tiny amounts can cause musty aromas and flavors in wines. TCA (2,4,6-trichloroanisole) most frequently comes from natural corks and gets into wine in the bottle. It can also come from barrels, pallets, and cardboard boxes. Although TCA taint will not harm you, it can ruin a wine. When TCA levels get high in a wine bottle it can make the wine smell moldy or musty, like cardboard, damp cement or wet newspapers.

Sulfur — Sulfur has the unmistakable scent of rotten eggs. Sulfur (not to be confused with sulfites) is commonly used in winemaking, in small amounts. But, again, when the levels become higher through over use it causes hydrogen sulfide to form resulting in stinky wine.

Vinegar Taint — It’s a common phrase used when wine goes bad — “It’s turned to vinegar.” Well, what actually happens is that Acetic acid builds up in wine when there’s too much exposure to oxygen during winemaking and is usually caused by acetobacter which is indeed used in the vinegar-making process. You’ll immediately notice the sharp vinegar smell that’s also been described as being like nail polish remover.

Brett — This is another common fault that’s attributed to yeast spoilage. “Brett” is short for Brettanomyces. And, again, your nose will immediately let you know of this spoilage that’s been described as smelling like a barnyard, a stable, a cow pie or a sweaty horse blanket. For those city folks who haven’t had the barnyard experience, Brett has also been described as oddly metallic or like the aroma of a Band-Aid.

The above wine faults are attributable to problems that are introduced at the winery. The next two are handling faults that happen anywhere between the winery and your wine glass.

Heat Damage — A sealed bottle of wine can be damaged or destroyed by getting too hot. In wine country, wineries warn you not to leave your purchases in the car and welcome you bringing wine that you’ve purchased elsewhere into their tasting room to keep it cool. But, heat damage can occur during shipping, on a store’s shelf, during a delivery that sits on your hot front porch, or simply after you purchase a bottle. Never leave bottles of wine out at room temperature for a prolonged period. A home refrigerator (typically in the low 30s F is too cold but better than nothing. In round numbers, white wines should be stored in the 40 to 50 degrees F range while reds should be stored in the 50 to 60 F range.

Light Damage — This is another problem that can just as easily happen in the store as in your home. When wine is exposed to prolong sun light, or simply just near a window, it can rapidly go bad. Here again you can get strong odors (wet wool) that will immediately let you know the wine has gone bad.

So, let your eyes and nose help you detect wine faults. And, ensure you properly handle and store your wine bottles once they are in your possession. Cheers!