TAKING A LOOK AT THE GNARLY WORLD OF WINE FAULTS

Woman with a disgusted expression

Wine is undoubtedly one of the great hedonistic pleasures of the world. While we technically don’t need wine to live a full and rich life - certainly, some people have no interest in it at all - for many people, wine adds texture, intrigue and/or sensual pleasure to daily living.

The consumption of wine brings much joy in no small part due to the unique flavours and aromas that are found in the glass and on the palate. A small pour of wine in a simple glass can contain everything spanning from floral notes to fruit notes to damp earth and pencil shavings - these can all be found to thrill the average wine consumer, and even more so if the consumers are enthusiastic wine lovers and/or students of wine.

However, there are unfortunately times when the wine in the bottle does not deliver on the hedonistic promise that many people have come to expect. Errors in process, elements in the natural world, poor hygiene, improper storage and sometimes just plain bad luck can lead to the developments of faults in wine.

Some more common than others, wine faults are actually a fact of life in the wine world.

Now, it’s worth noting that with the general improvements in winemaking practices, faulty wines are becoming less common than they have been in the past. BUT - faulty wines do still exist, much to the vexation of those consumers who can detect and identify them.

Have you ever opened a bottle of wine, poured yourself a glass, swirled, sniffed, tasted….and then wondered if the wine was “off”? It can be hard to know….

This is why we’ve created this handy little guide to help you understand the most common wine faults that occur, why and how they may present themselves. Our guide is not aimed at wines that have gone bad because they’ve been open for too long - that’s another topic for another day. Rather, this guide is intended to educate you on spoilage that happens before you even crack the bottle open. It can definitely get gnarly!

If you smell or taste these descriptors, you should know with confidence that you are likely better off seeking out a different bottle of wine to enjoy!


12 COMMON WINE FAULTS AND HOW TO DETECT THEM


1. 2,4,6 - Trichloroanisole (“TCA”)

Commonly referred to as “cork taint”, this fault gives often rise to a musty, moldy odor that is similar to a cold damp basement. In the most offensive cases, the wine will display overtly unpleasant aromas. In less extreme cases, the wine may taste less flavourful and/or muted. In all cases, though the wine may not be very pleasurable, it is not harmful to ingest.

TCA is a chemical that is generated in part by a mold that can grow on the bark of the cork oak tree but it is also found on winemaking equipment and more broadly in a winery itself. TCA is very persistent and rather prevalent - once it enters an environment, it can be hard to avoid. It can even get through screw caps and artificial corks to infect a wine!

TCA is detectable by humans at relatively low thresholds. Some people are able to detect it at concentrations of 2 to 7 parts per trillion.


2. Sulfur Dioxide

Though sulfur is a common and necessary addition to most wines (natural wines often avoid the use of sulfur as a preservative but for all other wines, sulfur is utilized at different points in the winemaking process), wines with excessive levels of sulfur dioxide demonstrate a smell that is similar to burnt matches and can cause a burning sensation in the throat and nose. The more acidic the wine, the more sensational the burn!

3. Hydrogen Sulfide

While exposure to too much oxygen can be an issue for wine, too little contact with oxygen can also be an issue for wines that have been treated with sulfur. In these situations, hydrogen sulfide can form and accumulate, resulting in an odour that smells of rotten eggs. This happens most often when a wine has been in contact with dead yeast sediment within an enclosed barrel for too long.







4. Mercaptan

Sometimes, a compound called ethyl mercaptan may form when sulfur and ethyl alcohol (also known as ethanol) combine. This can result in an odour that is often described as being reminiscent of the smell of garlic and onions.


5. Acetic Acid

Formed by a bacteria called acetobacter which converts alcohol into acetic acid a.k.a. volatile acidity or “VA”. Wines affected negatively by acetic acid give off a pronounced vinegar smell. While a little bit of volatile acidity can give wines a lifted character, too much masks the fruitiness of a wine and is therefore considered a fault.

6. Butyric and Lactic Acid

Both caused by the unwanted action of bacteria, the former causes odours that are reminiscent of rancid butter whilst the latter gives off an odour that is described by some wine professionals as being akin to sauerkraut.

7. Ethyl Acetate

Produced by yeast and/or acetic acid bacteria, ethyl acetate smells of nail polish remover. It is closely related to the idea of volatile acidity (see above) in that it is thought to heighten the perception of VA. It should be noted that some describe the odour associated with ethyl acetate as being very reminiscent of airplane glue! Like acetic acid (above), a little ethyl acetate might be fine but too much is not a good thing.

8. Geranium Fault

The smell of geraniums - now how can that be a fault you might wonder? Well low and behold it is - if you smell crushed geranium leaves, your wine is indeed faulty!

This offending odour is caused by an unwanted interaction between lactic acid bacteria that has grown spontaneously and sorbic acid (which is sometimes used as a preservative that is intended to prevent the growth of mold and bacteria) in finished wine. This wine fault is more commonly encountered in sweet, low alcohol wines.

9. Brettanomyces

Aaah Brett! Now this is a controversial one.

Some love it at low levels, others hate it altogether and are very sensitive to it. Regardless, most would agree that a wine that is affected by Brett definitely gives off barnyard funk vibes. Think “horsey”, “sweaty”, “dirty floor”… and you’ll get the picture.

A very invasive yeast that is present on grape skins and on winery equipment such as barrels, once Brettanomyces takes hold it can be very difficult to eliminate. Good hygiene in the winery and testing are key to prevention and detection, and there are some processes that can eliminate the off-odours that result from this bacteria. It is for the consumer to decide what level of Brett contamination is unacceptable to them.



10. Acetaldehyde

Part of the aldehyde group of compounds found in wine, acetaldehyde forms when oxygen interacts with the ethanol in wine and is always present to some degree in wine. However, it becomes a problem when there is too much.

In other words, or perhaps more colloquially, this is when a wine is exposed to air and becomes “oxidized”. Too much acetaldehyde will give wines a flat profile, devoid of sufficient fruit character. Acetaldeyde at detectable levels is rarely desirable, except if you are sipping on a glass of fino sherry, in which case winemakers actually strive to make sure this is central to the character of the wine.

11. Maderized Character

Sometimes wines are inadvertently exposed to heat, and this gives them a “cooked” or “baked” quality that takes away from the fresh fruit character of the wine. This is not desirable and is considered to be a wine fault unless you are drinking a glass of Madeira (from the island of Madeira) in which case this profile is actually central to the winemaking process.



12. Other Off Odours

Let’s just call this a catch-all bucket for a range of less than desirable odours that might be present in a wine. For example, a wine may smell or taste “green” or “stemmy” due to the use of underripe grapes or stems, “moldy” due to the inclusion of moldy grapes, “yeasty” from too much time in contact with dead yeast cells, like wet cardboard, or like stagnant water, or even “rubbery”. These are indeed all aromas and flavours associated with legitimate wine faults.


And there you have it, a list of twelve faults that could possibly be influencing your wine experience negatively. One final note - if you’re not sure, ask a wine professional if you can find one around and see what they think. Most wine professionals are well trained and experienced in the art of spotting a wine fault!

Cheers!


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