Part III · Tasting · 3 min
Faults
How to tell a wine you dislike from a wine that is broken, and what to do about it in a restaurant.
The distinction matters because one is a matter of taste and the other is a matter of fact. A wine you find too oaky isn’t faulty. A wine that smells of wet cardboard is, and you’re entitled to another bottle.
Cork taint
The most common fault, caused by TCA (2,4,6-trichloroanisole) forming in the cork. It smells of wet cardboard, damp basement or a mouldy dishcloth.
The trap is that TCA doesn’t mainly add a smell - it suppresses fruit. Severe cases are obvious. Mild cases just taste muted and disappointing, and are routinely mistaken for a dull wine. Human detection thresholds vary enormously, so one person at a table may find a bottle undrinkable while another notices nothing.
It affects a low single digit percentage of cork sealed bottles, and it’s the entire reason New Zealand moved to screwcaps.
Oxidation
Too much air, through a failed seal, poor storage or simply age. Whites go deep gold and taste of bruised apple and nuts; reds go brown and lose their fruit. Leave an open bottle on the bench for three days and you’ll have made a perfect reference sample.
Maderised is the word for the far end of that: the colour goes brown, the fruit goes, and what is left tastes flat and slightly cooked. It’s named for Madeira, which is deliberately heated and deliberately dark. Anywhere it isn’t intended, it is a fault.
The others
| Fault | Smells of | Verdict |
|---|---|---|
| Volatile acidity | Vinegar, nail polish remover | A trace is normal and makes the wine smell brighter. Past a point it takes over. |
| Brettanomyces | Farmyard, bandaid, horse blanket | A little is character to some people. A lot is spoilage to everyone. |
| Reduction | Struck match, burnt rubber, boiled cabbage | Often blows off - swirl hard or decant before rejecting |
| Refermentation | Unexpected fizz in a still wine | Faulty, unless the wine is meant to be lightly spritzy |
| Heat damage | Stewed, flat; often a pushed up cork | Ruined in transport or storage; not recoverable |
Reduction is worth singling out because it’s the one fault that frequently fixes itself. Pour the wine hard into a decanter, wait 10 minutes, and smell again. A surprising number of "faulty" bottles are simply tight.
Sending a bottle back
You can return a faulty bottle. You can’t return a bottle you have decided you don’t like, and staff can tell the difference immediately.
The form of words that works: "I think this might be corked - would you mind checking it?" It isn’t a complaint, it invites a second opinion, and any competent server will smell it and replace it. Restaurants can usually recover the cost from the supplier, so nobody is out of pocket. Say something the moment you suspect it, not after two glasses.