Sniffing the Cork

                                                             by Arthur Z. Przebinda

The notion that sniffing the cork will give you an indication of the wine’s character or quality is both myth and rooted in some reality. It all has to do with the production of corks and some greedy people a long time ago.

Corks are made from the bark of an oak tree most commonly found in the southwestern part of Europe. During production, corks are cleaned and sanitized. Sometimes, chlorine in the sanitizing solution interacts with fungi infecting the bark, creating a substance called trichloroanisole (2,4,6-trichloroanisole, TCA). This substance is not always completely flushed out and remains in the cork until bottling. Some say that, if present in large amounts, it can contaminate all the corks in a container.

TCA will seep into the wine causing it to be “corked”. These wines typically smell foul or musty. Some compare the smell to old dish rags or moldy cardboard or moldy newspapers. In the mouth, the wine is harsh, almost bitter, sometimes with an ash-like textural quality. The intensity of these characteristics is proportionate to the amount of TCA present. A wine with very minute amounts of TCA, can seem muted or “stripped” of aroma and flavor.

Statistically, 5% to 10% of bottles of wine produced are corked. This is one of the reasons some producers are opting for screw caps or synthetic closures. Corked wines are harmless and cause no untoward health consequences.

The seed of truth in the “smell-the-cork” myth is that, sometimes, one can smell TCA in a cork. A wet but untainted cork, though, can’t always be distinguished from one that is slightly tainted. The best way to determine if a wine is corked is to sniff and taste the wine itself. However, there is one more reason for the server presenting you with the cork and it is a historical one.

Many corks are stamped or imprinted with any of the following: the vintage year, the logo or name of the producer or the words: “Mis en Bouteille au Domaine”. The latter means “bottled at the estate” in French. The practice of placing these markings on corks came about as a measure to combat counterfeiting of wines. Additionally, some restaurateurs were once in the practice of pouring lower quality wine into an empty bottle left after a more expensive wine and, after closing the bottle with a new cork, re-selling it to unsuspecting customers. This rarely happens today and there is no reason to suspect that you will be a victim of this practice.

It is reasonable, however, to expect that the bottle you have ordered be opened at your table. The server may then hand you the cork or place it on the table in front of you. Feel free to pick it up and look at it. The main thing to check is if the vintage and producer on the label match that on the cork. If they don’t, you have every right not to accept the wine.

If the cork is natural, you might see mold on the outer end of the cork. This is not necessarily cause for alarm because it’s not an entirely uncommon occurrence and mold on the outside of corks does not mean that there is TCA in the wine. Finally, some corks may be more brittle but a crumbling cork does not necessarily bode poorly for the wine and is common with older wines.

Ultimately, you should focus on the small pour of wine you will be given. Smell it and taste it. If the wine is corked, the restaurant should replace the bottle. If it is not corked, but you just don’t like it, you will often be expected to pay for the bottle.


Arthur Z. Przebinda

Arthur is the founder of, a web site established in 2006 as a one-stop location for general wine information with an emphasis on education and opinion about California’s Central Coast wine region, wineries and winemakers. He is the author of articles and commentaries on his site and is the sole wine critic for He has created educational content and other materials used at wine festivals. He has been consulted as a wine expert by wineries. He has also been featured as a special guest columnists on Appellation America.