Wine Faults and Bad Wine Smells

Bad Smells are Just Part of What Can Go Wrong With a Bad Wine Defect

View our previous post – How Wine is Described By Those Snooty People Who Invent Terms Like Terroir

Drinking wine can be a sublime experience when everything comes together for the perfect glass. But what about those less than perfect glasses where the wine is a little flawed or badly flawed? These defects are usually called wine faults and there are lots of different types. Ever smell a wine that reminds you of a wet dog? That’s a wine fault often caused by a tainted wine cork or some other bacteria or unwelcome “guest”. White zin started out as a defective wine where the zinfandel grape juice didn’t fully ferment leaving some of the fruit sugar. Some would claim that it is still a faulty wine…just sayin’. How about a wine that smells like finger nail polish remover…doesn’t that sound appealing? That’s another wine fault caused by a chemical called ethyl acetate. We were tasting last week and a friend smelled a glass of wine and thought it smelled like a dog fart. When our dog farts, he often leaves the room so I’m gonna guess that it wasn’t a compliment.

The point is that wine can have almost as many types of faults as there are types of wine and those faults are caused by a myriad of problems. Flaws in wine generally stem from four main problems:

· poor vineyard management practices
· issues with the wine grapes
· contamination during the fermentation through bottling process
· poor storage conditions.

If the winemaker has successfully navigated these hurdles, there is a good chance that the wine will be good until it gets into your hands. After that, it’s up to you not to screw it up.

Poor Vineyard Management
Starting from the earliest part of the winemaking process, the vineyard itself can cause serious problems. Long before the first wine is ever made, the decision of how and what to plant can condemn a vineyard to mediocrity. It’s a well known adage in the wine industry and we’ve quoted it many times in our blog. You can’t make good wine from bad grapes but you can make bad wine from good grapes. If the vineyard is producing poor quality grapes, the wine will always be flawed. Poor quality wine grapes can stem from planting the wrong type of grape vine for the growing conditions to poor management of the vines themselves. Other causes are over watering, neglect in thinning out the wine grape crop, incorrectly pruning the canopy and cordons (the branches on a grape vine) or over fertilizing. Yes, wine grapes really need to struggle a little to produce good fruit. A happy wine grape vine actually makes pretty bad wine.

Poor Wine Grapes
Assuming the vineyard manager passed winemaking 101 and actually has managed the vineyard correctly, the winemaker enters the picture. Usually it’s the winemaker that decides when and how to harvest the grapes and in order to understand the process, we take a quick detour into basic chemistry. Stop groaning, I promise it will be short. Very young wine grapes are highly acidic meaning they are very tart. As the wine grape matures, the level of acid begins to drop and the sugar level goes up. Close to harvest time, sugar levels in grapes can rise several percent per day. The best wines have a good balance between acid and natural sugar from the fruit. Pick a grape to soon and the wine will be sour due to the preponderance of acid. Wait to long and the acid all but disappears and the grape is left with all sugar and very little acid and produces wines that are called “flabby”. Wait even longer and the grapes begin to dry further and lose moisture, concentrating the sugar and creating a flavor that is often called “stewed”. The best wine grapes retain that balance of fruit and acid.

Did you ever hear that old saying, “Cleanliness is next to Godliness?” It’s especially true in winemaking. Contamination can enter the winemaking process anywhere from crush to bottling. At best, contamination merely changes the flavor of the wine but catastrophic contamination can actually kill the yeast that is fermenting the wine, making the entire batch, really bad grape juice. Contamination can come in the form of dirt, chemicals or undesirable living organisms…and no, I’m not talking about your mother-in-law. There are a host of native and non-native yeasts and bacteria just waiting to have their way with the maturing wine and if they violate it, the result is a disaster. One of the most common types of contamination comes from moldy corks, causing the wine to be corked.

Poor Storage Conditions
Aside from storage at the winery and transport, this is where the wine consumer can still screw up even a great bottle of wine. Allowing a cork to dry out, storing wine in an area with large temperature or pressure swings or just keeping it the wrong amount of time all induce faults in wine. Dry corks are usually caused by storing wine upright instead of laying on its side. A dry cork shrinks allowing more air in the bottle and wine to escape due to an imperfect seal resulting in an oxidized wine. Wine temperature and pressure swings result in the same problem as air moves in and out of the bottle prematurely aging the wine. Perhaps the most lamentable is opening a wine too soon or waiting too long to enjoy it. Try opening a Cabernet Sauvignon that was designed to age for 20 years right after it was bottled and I can almost guarantee that it will taste very harsh. On the other hand storing a wine that was made to be enjoyed within a couple of years of vintage for 20 years may give you some great vinegar but the wine will suck.

These are the most common types of wine flaws. It’s a shame that most are preventable but too often, wine abuse (something that I believe should be punishable by a prison term) is a just an act of simple neglect or ignorance.

Winery-Sage is an online Winery Encyclopedia designed to help you compare wines, wineries, and regions by using a unique database. Cross-reference varietals and the wineries that produce them, as well as discover events sponsored by wineries and associations. We’re not here to sell you anything or pass you off to paid advertisers, just share the love for wine. Discover California wines at