Wine faults and how to spot them!
Posted on May 02 2018
By Tom Jenkins
Oxidisation occurs when the wine has been exposed to too much oxygen. Like leaving the core of an apple out after eating it, it goes brown. Oxidisation in unopened bottles of wine is caused by faulty closures or mishandling. Wine in a half empty bottle left lying around for several hours will also start to spoil unless you use a wine preserving tool, with which it should keep for a couple of days. Unfortunately, there’s not a lot that can be done about oxidised wine, aside from getting rid of it and opening a new bottle. Spotting oxidised wine is easy when you know what you’re looking for. It will appear more brownish in colour and taste more bitter, however if you’ve already had a couple of bottles it may be hard to spot.
A wine is corked when a chemical called TCA contaminates the wine at some point during production. It is usually caused by real cork, hence “corked”, but can also be present in oak barrels or processing lines which can spoil entire batches. Corked wine smells like wet cardboard; this is what you should be looking out for when the sommelier in a restaurant gives you a taster of the wine you’re about to buy.
Most producers add sulphites to their wine to act as a stabiliser. Sulphites are also a naturally occurring bi-product of an unhealthy fermentation, in which case they might leave an unpleasant smell of rotten eggs, which will ruin your drinking experience. Although sulphites aren’t harmful in the quantities found in wine, some people are allergic to them causing nasty headaches.
Top tip: if you suffer from headaches the day after drinking wine, try low sulphite wine!
Caused by residual sugar in the bottle, secondary fermentation causes the wine to have a spritz to it when it shouldn’t. However, not all secondary fermentation is a fault. Some winemakers will use this process to give their wines a little kick, it also occurs naturally in wines like Vinho Verde or some Grüner Veltliners. In order to spot this fault, it is important you know what you’re buying, so just do a little digging if you’re unsure.
Heat and light damage
Exposure to heat or light can ruin a bottle of wine. Heat can make the wine smell jammy and processed, it can also cause the closure to fail and lead to oxidisation. Light damage will most commonly affect wines in clear bottles (usually white and rosé) and will make the wine taste like a wet cloth. To avoid both of these faults, find a place that is cool (around 12ºC), dry and dark to store your wine.