The cork stopper has accompanied wine for centuries, and to this day, it is considered the most reliable means of sealing a wine bottle. It is unlikely that this will change anytime soon. Judging by current statistics, cork remains the most preferred material globally. Nevertheless, the cork has its drawbacks and problems, which is why alternatives are constantly being sought, the most famous of which is the screw cap.
The cork stopper is produced from the bark of the Quercus suber oak tree, which is most widespread along the western coast of the Mediterranean – Spain, North Africa, and especially Portugal (the oak forests there produce 50% of the world's cork stoppers). The shape of the cork stopper is cylindrical, and its length can vary between 25 and 60 cm: the longer it is, the more aging potential the wine sealed with it is presumed to have. Regardless of the quality of the cork, a defect can occur, which is the main reason an alternative is sought. This defect is caused by the chemical compound 2,4,6-trichloroanisole (TCA) and bears the same name – "cork taint." When it is present, we speak of "corked" wines. There is no way to know if the wine is infected with TCA before opening the bottle, nor can the condition of the cork stopper when removed from the bottle tell us anything more. Examining and smelling it by waiters in some restaurants is a ritual with little meaning: the stopper can have a perfect appearance, yet TCA may be nestled in its channels.
TCA is a highly sensually recognizable substance: human senses detect it in wine at levels of about 2-5 parts per trillion (ppt), which is equivalent to 0.000000000002 grams per liter of wine. To visualize this, the ratio is like 1 teaspoon of salt in a thousand Olympic-sized swimming pools. Human senses quickly adapt to the smell of TCA, meaning if the first sniff tells you the wine is corked, it most likely is. Often, the aromas are compared to the smell of wet dog fur, musty cardboard, or a dirty rag. The more you smell, the more you might doubt your judgment, so trust your first impression.
This unpleasant effect is the main reason for seeking alternatives for sealing wine bottles.
The screw cap is a long aluminum plate placed on the neck of the bottle. A layer of synthetic material or cork is used as a seal. Additions to its main advantage (inability for TCA to develop) include the possibility of horizontal storage and a significantly longer preservation of aromas in an open bottle of wine. At this stage, there is still a lack of extensive statistics on how wines sealed with it age. It has been used in wine for less than 50 years, and bottles sealed with it that are over 20 years old are single specimens, largely found in the private collections of wineries precisely for observation purposes.
Although it is difficult to implement in some traditional markets, the widespread perception that screw caps are primarily used for inexpensive wines is unfounded. Wines sealed with screw caps are not cheaper or of lower quality than those sealed with cork. The decision is much more technological and stylistic: innovative countries such as New Zealand, Australia, USA, Switzerland, and Austria use screw caps for over 80% of their wines, while traditional producers such as France, Italy, and Spain (Bulgaria belongs to this group) prefer cork stoppers.
Certainly, the screw cap is the more appropriate alternative for the HORECA sector, while in our wine collections, we prefer to see cork. It's all a matter of tradition and habit. So, the next time you choose a bottle, remember that the wine will be equally good, regardless of how it is sealed. The only advantage is that if you opt for a screw cap, you have a 100% guarantee of a quality product. But it cannot be denied that there is a certain emotional sentimentality in using a corkscrew.
