It would be great for everyone involved if we all could tell a corked wine from a truly bad wine, and knowing the difference can end up saving you money whether you are returning a bottle out on the town, or bringing it back to a retailer. Get to know what’s wrong with your wine! Learn about bad wine!
Corked wines, or wines affected by trichloroanisole (TCA), are the biggest problems in the world of wine. The level of TCA is what can be the issue, ranging from barely perceptible to overwhelming.
When it’s really obvious, corked wines smell of moldy newspapers, damp socks, mold and mushrooms (though many old wines develop that mushroomy aroma naturally). When it’s below our level of detection TCA still can crush a wine by stripping it of its fruit, leaving it out of balance and shrill.
Brettanomyces is the by-product of yeast activity in a wine, though not the good yeast that converts sugar to alcohol. It is usually present in oak barrels, though it does infect entire cellars, and is mostly closely associated with the wines of the Southern Rhône and to a certain extent, Tuscany -- though it can, and does, appear in every major wine-producing region.
In low concentration Brett can add great complexity to a wine’s bouquet. The typical positive descriptors tend to be a little funky, like barnyard, horse blanket, horsey, sweaty and/or cheesy. In higher concentrations, the aromas of Brett are typically created by three distinct chemical compounds, one of those -- 4-ethylphenol -- smells exactly like Band-Aids!
As wine ages, it oxidizes. Just like iron rusts, oxygen converts certain compounds in wine into other, generally less desirable compounds. At a slow controlled rate this creates the complexity of aged wines. When a wine is too old, or has been exposed to too much oxygen either through a faulty closure or too much time in barrel, the aromas and flavors of an oxidized wine tend to recall toasted nuts, brown spices, and other tan flavors.
Oxidized wine is often referred to as Maderized. Madeira is a famous wine that undergoes an intentionally oxidative winemaking process, giving it a unique flavor profile and the ability to age nearly forever.
My wine is reduced -- what the heck? Well, just as a wine can be faulty if it’s exposed to too much oxygen during the winemaking process, a wine can be faulty if it’s exposed to too little as well! Without oxygen being introduced during the winemaking process, hydrogen atoms end up bonding with sulfur to produce hydrogen sulfides, which smell like rotten eggs.
If not dealt with, these hydrogen sulfides can combine with carbon atoms in the wine, resulting in skunk and rotten cabbage aromas.
Since we’re on the subject, it’s worth noting that there are sulfur dioxide aromas in wine that are a different class of fault than the hydrogen sulfides of reduction. Sulfur dioxide is easily recognizable as a sulfury (duh!) or struck-match aroma.
It’s worth noting that sulfur, used as an antioxidant and preservative in wine, is very common. Some producers now make wine with no sulfur added, and while these tend to be very expressive wines, they are also very prone to having bacteriological and re-fermentation issues in the bottle, which lead to whole slew of other faults.
This one is a bit of a doozy. First off, a little bit of VA, as volatile acidity is referred to, can really make a wine’s bouquet explode with intensity and depth, so a little is usually good. VA comes in two main forms: the first version is acetic acid, and gives wine a vinegary smell.
Over time, the acetic acid interacts with the alcohol and creates ethyl acetate, which smells just like nail polish remover, mostly because it is found in most nail polish remover! Now, I wouldn’t go around drinking nail polish remover -- that would be very bad -- but you don’t have to worry about drinking wines that exhibit this form of VA. In fact, many of the greatest dessert wines ever made exhibit noticeable VA!
Our Favorite Aromas
After all this talk about off aromas it's time we take a look at some of our favorite aromas, why they occur, and which wines we can find them in.
Read - Wine Nose for all the details