The musty aroma
The cork bequeaths several kinds of aromas to the wine. The natural quality of cork can be communicated to the wine by cork dust or if it is pierced when the opening of the bottle. Cork also captures smells, good or bad, in the room where the bottles are kept, then transmits them to the wine. What the consumer calls a cork taint is a smell of musty, earthy, mossy or rotting leaf smell.
What is TCA?
Where does cork taint comes from? Microorganisms that produce a smelly molecule – trichloroanisole (TCA) – when they attack chlorine compounds and influence the wine. Where do these chlorine compounds come from? From certain products used to wash the corks during their manufacture and also from products for the treatment of wood timber or storage pallets. Recent research has made it possible to consider corks free from defects thanks to a treatment with carbon dioxide in a critical state which eliminates the TCA. The first symptom identified is that the fruity aromas of the wine are masked behind aromas of fungus and mold, sometimes of damp earth, humus, moss. The diagnosis is confirmed by the tasting in the mouth: the same aromas are manifested, and an impression of dryness dominates. In general, aeration of the wine does not help matters; this defect may even worsen. Some producers or wine merchants are not reluctant to replace defective bottles if you bought them directly.
False cork taint
Be careful! Some aromas are similar to the one of cork taint without being it. They might be due to the use of old casks, to improper washing bottles, to the paper used to filter the wine, to a harvest affected by rotting or even to poor cellar hygiene. But the most pernicious effect of a defective cork is a mask of aromas, with no obvious cork taint. The wine seems closed, less aromatic, in particular less fruity. Only the tasting of another bottle can remove the doubt!