How to Spot and Fix Faults in Wine

Much like how some people have the ability to pick up subtle nuances in wine while others simply taste a delicious drink, some people are also more sensitive than others to picking up on wine faults. Here we’ll go through the different types of faults found in wine, how to detect them and tips on avoiding it even getting to this stage.

Oxidised Wine

When wine has come into contact with air, it can become oxidised, giving a distinct sherry-like aroma, sometimes even vinegary. Air can sneak into a bottle that’s been sealed the traditional way if the cork that dried out as a result of not being stored properly (see How to Store Wine to learn the dos and don’ts).

Oxidised wine can be spotted from its appearance, as red, white and rosé wines all take on a dull, brownish hue.

Unfortunately if a wine is oxidised upon opening there isn’t much you can do about it. The most effective way of stopping a bottle from becoming oxidised is by storing it correctly. This is also important once a wine has been opened, most bottles will last longer if you store them in the fridge after opening, even red wines.

Cork Taint

Despite the name, wine with cork taint or ‘corked’ wine has nothing to do with bits of cork floating in your wine. Instead this refers to wine which has been contaminated by the chemical compound TCA (2,4,6-trichloroanisole). This is often in corks but it can also be present in oak barrels or other parts of the winery which can affect whole batches of wine as well as individual bottles.

Corked wine typically smells musty and dank, and is often very flat and astringent, showing no fruit at all. You can usually spot it as soon as you get a whiff of the wine you’re pouring into the glass, so if something doesn’t seem right then bring the glass up to your nose for a closer sniff. Anomalies like cork taint can usually be detected through aromas alone, but it’ll also be prevalent on the palate if the sniff test isn’t enough and you feel the need to have a little sip.

Our top tip for sniffing out corked wine is to avoid just smelling the cork itself as this isn’t a fail-safe method for deciding whether a wine is off. Always pour some from the bottle.

There isn’t anything you can do to prevent a wine being corked as the contamination occurs during production. Unfortunately it isn’t something that can be fixed either.

Sulphur in Wine

Sulphur occurs naturally in wine and is also added as a stabilising compound. This normally helps rather than hinders the wine, however occasionally there can be too much sulphur which causes the wine to have a horrible smell.

There isn’t a way of preventing this however you can normally fix it at home by decanting. Decanting the wine exposes it to oxygen which helps to cancel out the sulphur. Silver can also help to neutralise the smell so try stirring your glass of wine with a silver spoon.

Heat Damage

If a bottle of wine is exposed to too much heat it can be damaged, also known as ‘cooked’. You can tell if wine is heat damaged by smelling it. Cooked wine will have a sugary, jammy smell. It is often oxidised as well because the heat can damage the bottle seal too.

There isn’t much to be done about wine which is already cooked but it can be prevented by storing wine at the correct temperature.

Light Strike

Light strike is damage caused by UV light. UV light can cause the naturally occurring b vitamins in wine to react with the amino acids to make sulphuric compounds. Delicate white wines and Champagne are more prone to light strike damage than others.

You can tell if your wine is damaged by light strike by the wet wool like smell. Similar to cooked wine there is nothing to be done once wine is damaged. Wine bottles are usually made from coloured glass to help prevent light strike but storing it properly will also help. The best place to store wine is in a dark place away from sunlight.   

Accidental Bubbles

This is when there are bubbles in non-bubbly wine. Accidental secondary fermentation can happen in bottled wine when there is a little too much sugar.

Some wines are meant to be slightly sparkling, or frizzante so this one can be a little tricky to spot! If the wine in question is a fairly young red wine then we would guess any bubbles would be the result of accidental re-fermentation.

The bubbles won’t do any harm of course but could affect your enjoyment of the wine. If you decant into a fairly deep decanter and give it a really good shake this can often help to get rid of the bubbles.

Faults in Wine that Aren’t Actually Faults at All

Wine Sediment

Sediment is the dark, grainy-like dregs that can be found in some red wines. It occurs either because the wine hasn’t been filtered during the winemaking process or due to ageing. As red wines age the tannins and colour compounds can fray away to make sediment. This is why sediment is more common with fine red wines that have been aged.

Sediment will always be harmless but might not feel pleasant to drink which is why some people may class it as a fault in wine. The best way to deal with a wine with a lot of sediment is to decant it before drinking.

Tartrate Crystals

Tartrate crystals are a type of sediment normally found in white wines with a high mineral content. They look like little slivers of glass or crystals. Although these may look rather alarming, they are actually are a sign of a high quality wine that hasn’t been filtered.

Tartrate crystals definitely won’t cause harm to ingest but you may wish to decant any affected wines to avoid this nonetheless.

Volatile Acidity in Wine (aka Vinegar Taint)

All wines have some volatile acidity (or VA), but if a wine has too much this can cause a vinegary or even a nail varnish-like smell. Sometimes this can occur by accident but some winemakers use it to develop complex flavours which can be achieved if the levels are controlled, although when the levels gets too high the wine basically turns into vinegar!

Obviously once a wine has turned to vinegar it will be pretty much undrinkable, but those wines with some higher levels of VA will have complexities which some drinkers enjoy, others just don’t like it, it’s all personal preference!

Brett (aka Brettanomyces)

Brettanomyces, aka ‘brett’ is a type of wild yeast used in the winemaking process to develop complex flavours in some of the more robust red wines such as Cabernet Sauvignon or Syrah. It’s quite often found in prestigious regions of France, especially the Rhône.

It can smell a bit horsey or farmyardy so these aromas and flavours are not for everyone! When more is used it can divide drinkers into those who can appreciate / like it and those who just don’t.