Wine faults
Would you recognise a wine fault? It can be tricky if you’ve not encountered one before. It might be useful during your WSET classes to request a faulty bottle if one gets opened in the prep room. It was really enlightening when one turned up with TCA, and now that damp musty smell is instantly recognisable.
Below are the seven faults that are covered at WSET 3 Level (2019 entry):
01. Oxidation
Often caused by a fault in the closure, it causes unwanted oxygen to come into contact with the wine, primary fruit flavours can be lost. White wine can turn a dark golden colour, and develop aromas of coffee, honey or caramel, red wine turns a lighter sort of brown colour.
02. reduction
This gives a wine an eggy, almost blocked drain character. Wine needs some oxidation (the slow gradual type), reduction happens in the absence of oxygen, quite a common occurrence in wines with a screw top closing. I have personally found this note in a red Burgundy at a tasting before, a vigorous swirl and some good oxygen contact will often dissipate the aroma.
03. sulphur
Added to all wines as part of their preservation. Too much will result in a struck match smell, with loss of fruitiness and too little can lead to oxidation.

04. Cork taint/TCA
This is what people mean when they say a wine is “corked”.The fault comes from a compound called Trichloroanisole, a hard note to detect, it can present itself in various levels in a wine, sometimes undetectable. After you’ve smelt it once, it’s much easier to identify an encounter with it. In high enough levels, the wine smells like damp cardboard. Have you ever stripped wallpaper off a wall with a steamer? Kind of like that.
05. Volatile acidity
You want your wine to taste fragrant and complex and need some acidity in order for that to happen, low levels of volatile acidity are important, however if they become too high the wine develops a vinegar or acetone type smell.
06. Brettanomyces (“Brett”)
A type of yeast, but one we don’t necessarily want in wine (saccromyces cervisae is the good guy). Back in the 1980’s most people assumed the sweaty horse saddle smell of a Southern Rhone blend was normal, that it was just an expression of the terroir, grape, winemaking technique. Not so, it was dirty tanks. Some people might like a little bit of this funky taste in their wines, I think I do too, but definitely in a more controlled manner.
07. Out of condition
Got a bottle of wine you’ve stored badly? You might open it and it’s lost it’s freshness and tastes dull and stale. Make sure you store you wine in a cool dark place away from any vibrations or direct light sources.