How does a wine get “corked” or “tainted”?

Corked wines are wines that have turned flat and lifeless– a truly horrible and disappointing experience. They happen because of the improper preparation of the cork stopper, and it turns the wine terrible (it is also known as cork taint). Cork taint happens because of a chemical called TCA (2,4,6 trichloroanisole) that strips the wine of its more complex flavors and smells. It does not occur regularly, but it does affect roughly 10 percent of all cork used in wine-making around the world. TCA develops when natural chemicals from the cork come into contact with the chlorine that is used as a disinfectant and sterilizer. Although there are controls in place to avoid contamination when bottling the wines by using a properly disinfected and cleaned cork stopper, it is unavoidable that some of the bottles produced will have cork taint. Read on to know how to spot corked wines.

Cork sealing is a traditional method of sealing wines. Cork is a biodegradable material made from the phellem layer of bark tissue of the Quercus suber (cork oak) tree from the lands of Spain, Portugal, or the Mediterranean. Suberin is a unique substance that makes the cork impermeable to liquids and makes it ideal as a wine stopper. Sealing wine bottles with cork has been the practice for centuries, but because of the advent of newer technologies and concerns for safety, screwcaps or even plastic stoppers have slowly started to replace the cork in wine bottles. Generally, screwcaps are considered to be TCA-free because of the completely sealed state of screw capped bottles, but some experts claim that it does not allow the wine to breathe as it could with a cork stopper, thus making the wine less appealing. However, if safety and hygiene are your number one concern, screwcaps will be your best bet because they are hermetically sealed. Not only that, but they are cheaper and easier to procure as well. No need to hunt for that disappearing corkscrew!

So why is corked wine considered unappealing in standard wine circles? Is it dangerous to humans?

At this point, you might be wondering if you just unwittingly poisoned yourself by having a glass of a corked wine. Not to worry – strictly speaking, TCA is not harmful to humans, but it will degrade the flavor of your wine. Corked wines are still usable and drinkable like for cooking (but honestly, who would want to drink a lifeless wine?), but its taste and standards have definitely been lowered. Since lightly corked wines are not easily detected except for those with extremely seasoned palates, the only clue you might have about your wine being tainted is if there are differences in flavor that you have not experienced before with that particular brand. Strongly corked wines, on the other hand, are easily distinguished because of their strong, musty odor. If you open a bottle of wine and smell a strong whiff of something moldy or smelly, it will be best to put the bottle down.

How to spot corked wines, a.k.a. the bad ones?

Due to the nature of cork and its ability to allow oxygen to let the wine breathe, it is inevitable that nasty microscopic organisms and bacteria could get inside and affect improperly sealed bottles. Cork taint corrupts the quality of the wine, leaving you with a sad, lackluster version of something supposedly tasty and sumptuous. The chemical TCA produces a wet-dog, moldy, newspaper smell that is unmistakable to the senses, especially for seasoned sommeliers. Cork taint affects up to a tenth of wine bottles that use cork stoppers.

There are ways to spot a corked wine before you serve it up to your friends and guests. First is by simply smelling it, or secondly, by tasting it. A telltale sign of corked wines is the aforementioned bad, musty smell – people generally describe it as having a dank, stale scent. If the wine smells off, it probably is plagued with cork taint. Despite what the wine community would typically say, smelling the cork of a corked wine does not automatically tell if it has cork taint or not. You must smell the actual wine and not just the cork.

Still not sure?

Try the taste test. Take a small sip of the wine – if it is a corked wine, it will taste dull, flat, and with no fruity notes whatsoever, especially with white wines. If you have tried a specific brand before and the taste is not what you remember it to be, it probably is corked. You should not drink the wine if the taste is not what you expect it to be and somewhat reminds you of alcohol or an astringent. Sometimes when the wine is only slightly corked or tainted, the taste will not be as apparent to others (as with the case of red wines), and it would require a sensitive wine drinker to spot it. If you are drinking with friends, try asking their opinions as well to be sure. In some cases, shops will accept a return on the corked wine as long as you ask and explain the situation nicely.

Try AEOS AUCTIONS wines and experience a worry-free purchase. Life is too short to be drinking subpar wines!

References:
5 Scary Wine Faults and What You Should Know | Napa Valley Wine Academy
Everything You Ever Wanted to Know About Cork Taint | Wine Enthusiast Magazine (winemag.com)
Is Cork-Sealed Wine Really Better Than Screw-Cap Wine? | Taste of Home
Ask a Somm: How Do I Know if a Wine Is Corked? – Eater
Trichloroanisole: Cork taint | Podcast | Chemistry World