Right on the Nose: Finding Wine Faults with a Sniff

A bottle of wine is meant to have fragrant aromatics and a wonderful harmony of flavors. But when someone opens the bottle and you’re greeted by the scent of burning rubber, a moldy basement, or a pooch that badly needs a bath, then you know something’s not right.


Cork Tainting

Most vintages are corked to preserve the spirit, flavor, and aroma. There’s nothing wrong there. However, during wine production or in the bottling process, the cork might have come in contact with a contaminant chemical called 2,4,6-tricholoranisole (TCA).

TCA is formed when fungi latches on to plant-based items like cork and oak barrels, often occurring when cork is placed in a hot and moist environment. The chemical isn’t harmful to humans, but it can certainly turn fine wine into a musty mess.

The same could happen to oak barrels used for storing wine.

Cork tainting is quite common though it only affects around 3% of wine around the globe. A lot of avid wine drinkers have encountered it. But not all can tell that the wine is tainted, as a person’s sensitivity to TCA varies.

Aroma: The wine takes on a musty odor that is similar to the scent of wet cardboard, drenched newspaper, or a cobweb-filled attic that contains old wooden furniture. People who aren’t sensitive to TCA will only find faint traces of the odor, but the smell will worsen over time.

Taste: Similar to its aroma, corked wine has musty, wet cardboard-like notes. The fruity notes are diffused and the finish is suspiciously short.

Low levels of tainting are hard to notice and drinkers could have already consumed a good amount of wine before noticing the wine fault. In this case, returning the bottle won’t be an option.


Wine Oxidation

Wine should be stored in sealed bottles and a controlled environment. Prolonged exposure to air contaminates the vino and breaks down some of its chemical components, altering its taste and aroma. The properties of crisp vintages are bound to suffer. But there are also wines that wind up with better varietal qualities after a brief exposure to oxygen, like Sherry and Madeira.

Oxidized red wine loses its luster literally, having dimmer hues and results in less pronounced flavors. Reds, however, are normally more resistant to oxidation, since their tannins serve as a protective layer against the altering effects of oxygen.

Wine storage facilities are great options to keep oxygen away from the “sensitive” beverage.

Aroma: The scent of oxidized whites is similar to apple cider, vinegar, or Sherry. Reds, on the other hand, have diminished fruit character with an odd tinge of caramel.

Taste: Oxidized whites gradually lose their taste and possess duller notes. Reds become a tad bitter, drier on the tongue, and develop an added flat note that is similar to lightly flavored clear soup.


Reduced Wine

As mentioned earlier, wine suffers from prolonged exposure to oxygen but being in a reduced state comes as the exact opposite. Some oxygen is necessary during the production and aging processes of winemaking. The lack of oxygen stops the sulfur compounds in wine from transforming into hydrogen sulfide, thus raising the finished product’s sulfur content. The resulting qualities are disagreeable but treatable.

Mild reduction can be treated through decanting or by swirling wine in a glass. Copper can also diminish the effects of this wine fault. Some experts drop copper coins in wine to address severe cases of reductive taint.

Aroma: A strong odor resembling rotten eggs, a sewage system, a freshly lit match, a skunk, or burning rubber is emitted by the wine.

Taste: In severe cases, the taste resembles its pungent aroma. Trust us, it is a horrible experience.



Pundits are on the fence with this wine fault. On one hand, some strains of Brettanomyces (Brett) yeast trample on a wine’s fruity notes and then superimpose a rancid note of wet dogs, sewer gas, or soil. On the other, certain strains of the microbe are cultivated in some wineries, as they add a diverse range of pleasurable notes.  

Unsatisfactory winery hygiene and red wine phenols attract Brett, making itself a foreign object in wine. Some wineries, however, have discovered that the right dose and strains of Brett can thoroughly improve their wine. They have made good money out of the previously odd combination.

Aroma: Brett has a wide range of scents given its multitude of strains. But it is commonly associated with the aromas of a band aid, a barnyard, and spice.

Taste: In the flavor department, all sorts of notes can emanate from Brett depending on the strain, quantity, and combination with wine. Associated notes are wood, savory meat, fruits, flowers, sewer gas, wet dogs, earth, and overcooked beans.


Heated Wine

Prolonged exposure to heat damages wine to the extent that it bears “cooked” characteristics. For this reason, wine storage is never found outside. A bottle that is directly exposed to sunlight or placed near hot objects for long periods will likely go bad.

Heat expands the molecules of the bottle’s contents. The cork pushed up or a little loose on the rim is a sign that wine has been tainted by the temperature. Conversely, if wine is stored in a particularly cold place, crystals may form at the bottom. Don’t fret for these things don’t really affect wine’s aroma and taste.

Aroma: Similar to cooking fresh ingredients, the scents of stewed fruits, raisins or jam emanate from the bottle.

Taste: Depending on the gravity of heat damage, the flavors can come as cooked or burnt version of the wine’s notes. Fruity notes taste like stewed fruits or caramel (in severe cases).


Volatile Acidity

A technique used by some wineries, acetic acid is formed when the acetobacter bacteria exchanges pleasantries with the wine. Mild cases endow a welcome tart note to the wine. However, if wine contains too much acetic acid, the beverage can turn into an unpleasant vinegar knockoff.

Aroma: Severe cases of volatile acidity replaces a vintage’s aromatics with the smell of acetone or vinegar.

Taste: In high doses, volatile acidity produces strong and sharp vinegar flavor with thin mouthfeel.

Picking up wine faults by nose gives a clear advantage to those who live a wine lifestyle. The moment you sense something wrong with a vino, you can return the bottle and have it replaced with a notable vintage. You can end the day on a high note while relishing all of your preferred notes.