Common wine faults and how to spot them

Wine contains a near infinite spectrum of amazing flavors… but wine faults are a part of the story, too.

Dirty diaper, wet dog, cardboard, nail polish and barnyard are not on the list. Once in a while you’ll get a wine that’s just not right. Sadly there are more than a few ways in which your wine can be damaged.

Volatile Acidity

What it is: acetic acid and ethyl acetate

How to detect it:  If you catch a whiff of nail polish remover or vinegar.

All wines have a minuscule presence of acetic acid, which is created by the common yeast strain in wine. At small levels in wine it’s undetectable. Once the levels rise it starts to give off a balsamic note. If you see “high toned” in the flavor description that’s a hint there might be higher levels of VA. Among the casual wine drinker this is probably the least offensive fault, often going completely undetected. However it’s still consider a flaw in higher concentrations.

Most countries have legal restrictions on how much VA can be present in a wine. It’s more common in wild fermentations and natural wines. The risk of VA increases if too many broken, rotted, or damaged clusters make their way into the fermentation tank. Also, wines that see long fermentation times, like Amarone or Barolo, or that spend longer times in barrel (Rioja Reserva) risk higher levels because they are exposed to more oxygen.

Cork Taint

What it is: A compound sometimes found in corks known formally as 2,4,6-trichloroanisole or TCA for short, that essentially strips wine of its flavor.

How to detect it: If your wine smells a bit funky, like moldy basement, wet dog, or wet cardboard and seems to lack any coherent fruit, flavors chances are it’s corked.

Cork taint was a much bigger problem years ago. It’s still a murky area though. In 2005 the Wine Enthusiast office blind tested 2500 bottles and found a whopping 7% contained TCA. However the cork suppliers themselves claim the figure is generally less than 1%. Corked wine isn’t dangerous to drink. It just doesn’t taste good.


What it is: A yeast strain made of 4-ethyl phenol and 4-ethyl guiacol.

How to detect it: Smells like bandaid, wet leather, or barnyard

Brett is another trait that in small amounts may be desirable to some, but the average consumer probably finds it fairly nasty.

After all, you don’t expect to get a whiff of band-aid and sweat in most modern wines. Old World wines had a lot of this going on, and it’s still common in more rustic winemaking environments. The typical modern winemaking environment is much cleaner so there’s less chance of brett spreading.


What it is: Over exposure to oxygen.

How to detect it: Smells like cooked fruit, nuts, sherry or burnt marshmallow. Visually, young red wines show premature browning on the edge and whites will become a tawny yellow or brown shade.

In older wines, oxidation is expected. In a sense it’s the most common fault. A 10 year old Chardonnay should have a bit of oxidation. A five year old one? Not so much. Think of what happens to an apple after you bite it and leave it out. It gets brown. Same goes for wine. Over time any wine will become oxidized. But sometimes it happens much faster. Premox has been a more common problem with white wines from Burgundy, Alsace, Bordeaux especially. Some people speculate the cork quality has reduced, pointing out wines with wax seals have less incidence of premox.

Heat damage

What it is: Pretty self explanatory. When a wine gets too hot it becomes “cooked” and loses much of its character.

How to detect it: Fruit flavors taste stewed, or cooked. Imagine the difference between fresh raspberries and ones reduced into a thick jam on the stove and then toasted in the oven. Most often, if the cork is pushed out of the bottle slightly, that’s a pretty good sign of heat damage.

We often hold shipments in the summer, especially to places like Texas and Florida. Just a few hours on a hot truck might be all it takes to damage a wine. The ideal storage temperature is 55 degrees. Inside a delivery truck it might hit 140+.