In the world of wine it often comes up a discussion which always brings up the same doubts and the same fears, it stays on for some months, producing vivid debates with plenty of victims, wounded and winners, then it is forgotten for some time and, punctually, it comes up again to upset the minds of wine lovers and producers. Anyhow the problem is serious and certainly requires attention: corks used for sealing wine bottles have become in the last ten years a disturbing and painful subject. We all like the romantic and traditional image of the cork we usually find on bottle's necks, the pompous ceremony of its opening always attracts the attention and the respect of the ones who are going to enjoy the content of the bottle, but when the cork is “tainted”, in a second the magic of the moment is vanished and replaced by true disappointment.

 Let's admit this, we are usually convinced a bottle sealed with a cork contains a better wine, that small cylinder of cork seems to promise an excellent wine, one of those “important” ones. Nevertheless quality does exist for corks as well, there are high quality corks and corks having very low quality. Perhaps the sight of a block of compact and tidy cork is the promising sign of an expensive and refined product, therefore better. Sure, it is just a matter of culture, our culture, that accustomed us to see “the good wine” contained in bottles sealed with corks, therefore the presence of a cork made of a different material disappoints this principle of quality. However anyone who knows wine sufficiently knows cork conceals a feared snare which is revealed only after the bottle has been opened: the possibility of the development of tricloroanisole, a chemical compound also known as 2,4,6-tricloroanisole and abbreviated as 246-TCA, that is the main responsible for the so called “corky smell”.

Synthetic corks: a complete and valid substitute for natural cork?

 Cork is an extraordinary material, from a physical and mechanical point of view it is an amazing miracle of nature, to tell the truth, one of the many. Its structure allows it to have remarkable elastic capabilities, even when subjected to strong compressions it is capable of restoring its original shape. Moreover it also has excellent hermetical qualities, in particular for liquids, and its structure allows it to “breathe” by the passage of tiny but precious quantities of oxygen from one side to another: its indisputable qualities are certainly useful for the keeping, aging and the refinement of wine contained in a bottle. There is still the inconvenient corky smell to disturb the scene, a fact that, according to recent figures, affects about 3-5% of the total world production of wine. If we consider that, it is not something to take lightly, it represents an economic loss for producers which is not negligible. Moreover it should be considered that not very expert wine consumers, not being able to recognize the corky smell, could misunderstand this defect as a sign of a low quality wine therefore having prejudices on the wine itself and on its producer.

 Since many years they are studying new alternative solutions to this problem and in particular they have been introduced on the market synthetic corks, produced with many chemical compounds, and that have good elastic qualities, just like natural cork, and ensure an absolute hermetic quality. In other words, whether natural cork allows the passage of a tiny quantity of oxygen to the inside of the bottle, an useful characteristic for the aging of some wines, synthetic cork does not guarantee the same function. Probably this is not the main problem connected to these corks, what limits the spreading of this solution is the prejudice of consumers, in other words, synthetic cork is not believed to have the same dignity of natural cork and it is often believed to be used for low quality wines. As a matter of fact many producers are already using synthetic corks in many quality wines, therefore, the prejudice connected to a lower quality of the product does not have any concrete reason. Let's admit that, the scarce acceptability of synthetic corks is simply prejudicial: we are still tied to the idea about associating quality wine to natural corks while forgetting that what we appreciate the most in our glasses is wine, not the cork nor the label.

 Does this seem to be a war in favor of synthetic cork and against natural cork? Absolutely not. Indeed, this is a war in favor of common sense. Natural cork offers indisputable advantages when compared to synthetic cork, thanks to its capacity of allowing the passage of oxygen ensure a better aging of the wine kept in the bottle, whereas synthetic cork, which offers a higher hermetic quality, does not allow any passage of oxygen. Researches done on the development of wine contained in bottles sealed with synthetic corks, have discovered that after about 18 months the organoleptic qualities of wine deteriorate, in other words, after two years, it seems, wine is not in good conditions anymore. On the other hand natural cork can be cause of the inconvenient “corky smell”, whereas synthetic cork does not. One could come up with the conclusion that natural corks are excellent for wines to be aged in bottle, with the risk of corky smell, whereas the synthetic ones are not suited for long aging. If we carefully consider the problem and wines offered by the market, how many of them are truly suited for long aging in bottle? Very few.

 Most of the wines produced, in particular white wines, have a pretty short “lifetime”, the same is true for many reds as well, usually believed to be suited for aging in bottle, they lose their best qualities after two or three years. We know almost the totality of white wines is to be consumed in their youth, preferably within two years from the time they were released on the market; white wines truly suited for long aging in bottle are few, very few. Red wines suited for long aging in bottle are expressly created by producers for this specific purpose, and they will certainly use natural corks for them. Most of the red wines produced are suited for a rapid consumption and they do not improve with the aging in bottle. Therefore synthetic corks are a good solution for wines not suited for aging and this is the intelligent choice many producers made no natter it is not very accepted by consumers. According to this point of view, this seems to be a guarantee for the integrity of the product while diminishing the risk of spoilage because of corky smell. Honestly, we do prefer seeing in bottles of cheap wines not suited for aging, synthetic corks instead of very bad and scarce natural corks of disputable quality. In wines destined to the aging in bottle, no, in those we expect to see high quality natural corks which ensure the best conditions for their aging.

 Whether synthetic cork is still a cause for the prejudice in many consumers, we would like to know what they think about another alternative solution which has been adopted by some producers already: screw caps. In case synthetic cork offers some possibilities to the ceremony of the opening of a bottle by using a corkscrew, screw cap does not even need that: a simple movement of the hand and the bottle is opened. Even in this case corky smell does not have any chance to develop and whether the acceptability of synthetic corks among consumers is pretty low, screw cap is even less accepted. Natural corks are expensive, in particular the ones produced from a single block, that is the ones which are suited for keeping and aging wine for a long time. Synthetic corks are cheaper and the prejudice still existing on their acceptability limits their usage and spreading. Maybe this is because of consumers being accustomed and attracted to appearance instead of substance: a bottle having a nice label and a cork promises an excellent wine, nevertheless experience and our senses teach us there are so many bottles with beautiful labels and corks containing wines not really excellent, indeed, truly disappointing.

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