Wine Oxidation: Causes And How To Minimize It
Wine oxidizes when exposed to air, causing a distinctive sherry-like off-odor and brownish tint that is increasingly recognizable with wine consumption experience.
When wine tannins are oxidized, hydrogen peroxide is produced which subsequently oxidizes ethanol into acetaldehyde - the principal compound producing the oxidized odor and masking the wine's fragrance. On opening a bottle, acetaldehyde generation can be detected within as little as two to eight hours, depending on varietal, age, amount of wine contact with air, temperature, etc. White wines and older reds are particularly susceptible to oxidation damage.
The biggest factor in oxidation is the amount of wine surface contact with air following opening and pouring. Therefore, wine preservation products that are most effective at reducing air contact with the wine surface will best reduce oxidation.