What’s that Smell?! Wine Faults 101

Wine faults can be difficult to detect, and unfortunately they can pop up in any bottle. Here is a quick and easy guide to identifying some of the more common wine faults. If you detect any of these don’t hesitate to send your bottle back.

Cork Taint

Cork taint is caused by 2,4,6-trichloroanisole also known as TCA. It smells like a musty, dank cellar or wet cardboard. Needless to say it’s a pretty unpleasant smell! TCA forms when molds and bacteria come in contact with chlorine during the cork production process. Although, it seems logical it cannot be detected by simply sniffing the cork.


Oxidation is indicated by a bruised apple, sherry, nutty smell. You can also tell if a wine is oxidized by observing the colour. Oxidation causes red wines to turn more brick red, and white wines to turn darker yellow and eventually brown. Very simply the oxidation of wine occurs during the aging process when ethanol comes into contact with oxygen. All wine becomes oxidized with age. However, if wine isn’t stored properly this process will be accelerated. Oxidation also happens if you open a bottle and let it stand instead of drinking it all in one sitting. This process can be prevented by using wine preservation methods or bottle stoppers.


Brett is caused by a spoilage yeast called Brettanomyces, and is introduced during the wine maturation process. This one is tricky because a lot of winos don’t mind the smoky, leathery, earthy smells that Brett imparts. However, too much Brett will overpower all of the natural characteristics of the varietal in question making it a fault.

Secondary Fermentation (Bubbles!)

When you find bubbles in your wine that shouldn’t be there it’s a fault! Secondary fermentation usually happens when the wine has residual sugar, and hasn’t been stabilized properly or was bottled in a non-sterile area. It can be very easy to detect especially if you’re drinking red wine. But, it’s important to note that some white wines have minor effervescence on purpose.


Sulfur dioxide is added to wine as a stabilizing agent. However, it is also produced by yeast as a byproduct of fermentation. Sometimes too much is added causing the wine to smell like a burnt match. If you smell a rotten egg smell this is also a fault. The rotten egg smell develops if the fermentation becomes stressed, because the yeasts aren’t receiving enough nutrients, and is caused by hydrogen sulfide.

Make sure to check out Rosehill Wine Cellars for all of your wine storage and wine drinking needs!