Select the first letter of the word whose definition you wish to obtain.
Chemical changes occurring as a result of contact with oxygen. Oxidation affects the aromatic properties of wine adversely if excessive (see maderised) but in the normal course of wine-making, a modest degree of oxygenation is beneficial, helping with the evolution of aromas (e.g. from fresh fruit to candied to cooked), and preventing the generation of hydrogen sulphide from the lees with its smell of rotten eggs.