It’s only“a very small cork”, as Sabine Paturel hums in a very forgettable song, but it can be a source of many frustrations and bitter memories. And even tragedies. Remember that the most treacherous of all, the champagne cork, is the leading cause of accidental blindness in France. Never point it at a face – at least while it’s in the neck. If you hold it in your hand, you can, it’s not a weapon in itself.
Basically, we don’t ask much from a cork, except to seal the bottle hermetically. Prevent air from entering, prevent wine from coming out. Fans of technique and mechanical engineers will be able to be passionate about the comparative elasticity of silicone and cork (in short, cork wins) and the sealing qualities of the latter. Another virtual parenthesis on this point: no, cork does not allow wine to breathe. It is perfectly waterproof and that is what we ask of it.
Better detection
But sometimes, in addition to corking the wine, he “corks” it. How the hell can a cork contaminate a wine? The responsible bears the pretty name of 2,4,6-trichloroanisole, nicknamed more simply TCA. There are two other molecules that give the bottle an unpleasant musty cork smell, but TCA is 70% of the time the culprit. It is synthesized under the action of molds, in the presence of chlorophenol, a chlorine derivative sometimes present on cork bark exposed to insecticides, or carried by the air. It only takes a few nanograms (10-9 grams) to contaminate an entire sheet of cork, and therefore several hundred corks. Once trapped in the bottle, the TCA will take over all the other aromatic molecules.
Good news, corked wines are increasingly rare. And mainly concern bottles over 10 years old. Because between the 1990s and today, we have gone from 15% of corks contaminated to 1.5%. Manufacturers have changed their cork processing methods. Corks are notably better cleaned, quality controls are increasing and the leaders have even developed systematic detection systems for TCA in their production.
In the glass, the detection threshold varies, depending on the human being who tastes the wine, his genetic heritage and his olfactory experience, between 1.5 and 5 nanograms per liter (if he himself is drunk, he detects it obviously much worse).
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