For many restaurants and operators, the wine list plays just as important a role in the dining experience as the menu itself.
Guests and hospitality professionals alike enjoy discovering and enjoying great wines, but what happens when, on the odd occasion, a wine doesn’t taste or smell quite right? Whether you work on the floor, behind the bar or in the kitchen, being able to recognise the most common wine faults and understand what might have caused it can be a valuable skill and can help you and your teams deal with any issues quickly and with confidence.
So, what is a wine fault?
Wine faults are, by definition, undesirable characteristics that affect a wine’s aroma, flavour or appearance. Most faults have a chemical or microbial origin and may naturally exist in wine at levels that are virtually undetectable.
However, when the concentration of these becomes too much, they can overwhelm the desired aromas and flavours of the wine ultimately making it unpleasant to drink. While wine faults don’t pose a risk to human health, some people are more sensitive to these unwanted characteristics than others.
Some of the most common wine faults
Oxidation
Oxidised wine is potentially the most common wine fault you’ll find. It occurs when a wine is exposed to too much oxygen, either due to a faulty closure (cork or screw cap) or if a wine has been open too long. As a result, the wine starts to turn brown, the aromatics fade, and a nutty, bruised apple characteristic evolves. It’s the same thing that happens when sliced apple turns brown.
Some styles of wine, such as sherry, are deliberately made in an oxidative style and will display these characteristics. However, when they’re found in young wines that are meant to be fresh and fruity, such as Pinot Grigio and Sauvignon Blanc, it is seen as a fault.
White wines are much more susceptible to oxidisation than reds because the tannins in a red wine act as a buffer. Most oxidation is easily prevented by proper wine storage, using either with vacuum pumps or inert gas, and your wine supplier should be able to advise on what would work best for your business.
Cork Taint
Commonly referred to as ‘corked’, this term doesn’t mean that there are pieces of cork floating in the wine, rather it refers to a chemical compound called TCA that contaminates the wine. Whilst this compound can usually be found in natural corks, it can also be present in the winery.
Cork tainted wines have a musty smell reminiscent of wet newspaper, mouldy cardboard, or wet dog, and any fruit flavours in the wine will be muted. The pungency of these aromas and flavours can vary from barely noticeable to overpowering. Cork taint cannot be removed from wine unfortunately, so careful selection of quality bottle closures is important.
Heat Damage
Wines can be heat damaged during transportation or storage. This typically happens when wine is left in hot environments for prolonged periods of time, such as cases left outside cooking in the sun or bottles kept in direct sunlight by a window.
When this happens, the wine loses its fresh fruit characteristics and tastes dull and stale. It might have jammy, cooked fruit, nutty roasted sugar-type aromas. Heat damage can often compromise the seal of the bottle (the expansion from the heated air pushes the cork out) and oxidisation can occur as well.
To avoid heat damage, wine should be stored at a consistent, cool temperature around 12 degrees and out of direct sunlight. If you’re unsure about storage or the potential for heat damage occurring on-site, your drinks partner will be able to support you with solutions.
UV Light Damage
Light strike or UV light damage occurs when wine is exposed to ultraviolet light, most commonly through storage in direct sunlight or under fluorescent tube lighting. The UV light reacts with components in the wine, creating unpleasant aromas that can resemble rotten cabbage, cooked vegetables or eggs.
Delicate wines, particularly Champagne and white wines like Pinot Grigio, are often more susceptible than reds. To help mitigate light damage, wine should always be stored away from direct sunlight or UV tube lighting.
The distinction between wine faults vs flaws
Wine flaws are minor characteristics that aren’t typically found in a wine, but they’re not usually severe enough to spoil it. In fact, some can add complexity and character. However, when a flaw becomes so noticeable that it overwhelms the wine’s other aromas and flavours, it is considered a fault.
A few of the most common flaws found in wine
Brettanomyces
Brettanomyces, sometimes referred to as ‘brett’, is a type of wild yeast found in wineries and can cause significant wine spoilage. It is most associated with barrel-aged red wines, although it can affect white wines. Brett may be present naturally on grapes or introduced through contaminated barrels.
Typically, brett dulls the fruitiness of wine leaving it with a metallic aftertaste alongside aromas of farmyard, horse, bacon and cloves. Sensitivity to brett varies, and while some people enjoy these characteristics at low levels, others dislike them. However, at high concentrations, brett is widely regarded as a fault.
Reduction
Reduction can occur during fermentation when the yeast doesn’t have enough nutrients or oxygen. Usually, it can be changed by the winemaker during the winemaking process, but sometimes it re-appears during bottling.
There are variable characteristics of reduction. Whilst at low levels the aromas may be described as smoky or gunflint and be reminiscent of struck matches which many people enjoy. At higher levels, the aromas can be very pungent and range from rotten eggs, cooked cabbage and burnt rubber to garlic.
Reduction is most detected when a bottle of wine has just been opened, but once it’s been aired, the unpleasant aromas start to dissipate after a few minutes. However, if it doesn’t disappear, then there’s perhaps a more complex problem which will spoil the wine.
Volatile Acidity
Volatile acidity (VA) or vinegar taint is a common wine fault caused by bacteria producing acetic acid and related compounds during the fermentation or storage. It can result from damaged fruit, fruit flies and poor winery hygiene, and accelerated by exposure to oxygen. At high levels, VA gives wine a vinegar-like aroma and is considered a fault.
Interestingly, VA is often undetectable at low levels and can be used by some winemakers to add complexity and lift a wine. However, opinions differ on the level of VA acceptable for premium wine.
What to do if a wine is faulty
If a wine doesn’t taste as it should, guests should be offered an alternative. Bottles used for by-the-glass service may remain open for longer periods and should be checked regularly for faults before being served.
Proper wine storage both on-site and during delivery is also important for stock management and commercial performance. While cork taint, oxidation, light strike and heat damage are clear faults, other flaws can add character and enjoyment.
Wine confidence through trusted drinks partners
Wine has always been at the heart of Matthew Clark Bibendum (MCB). Working with more than 280 producers across every major wine region, we help our partners create wine lists that delight guests and improve commercial performance.
Behind every wine recommendation sits deep wine knowledge, trusted producer relationships, and rigorous quality standards, giving our partners and their front-of-house teams confidence in every pour.
One partner for every pour. Head to Matthew Clark Bibendum to find out more.
Author: Sara Cranmer, wine development manager, Matthew Clark Bibendum
