Oxidized wine
In young white wines, oxidation is easily revealed by a darker or pink-orange tint, while red wines acquire a brownish color. Wine with high volatile acid content is easily identifiable by a smell reminiscent of vinegar or acetone and tastes dull and unpleasant, which is a sign that it is aged or completely spoiled.
Wine oxidation occurs when oxygen reacts with various components of the wine. A mild contact with air can be desirable, but it must be carefully controlled. For some types of wines, such as Madeira, Vin Santo, or straw wine, oxidation is a deliberate part of the production process. However, in the case of uncontrolled oxidation, undesirable changes occur, which can arise during vinification, either in a tank, barrel, or after bottling due to poorly sealing cork.