Variations of the Major Volatiles Through Aging of Sherry

Abstract

A study was made of the variations in concentration of the major volatile components of sherries during the various aging stages. These variations were found to be due to the biological or physical-chemical nature of the various aging processes used in the area. A series of enzymatic reactions take place in wine during biological aging caused by the metabolism of the yeast acting in the medium; these produce reductions in volatile acidity, alcohol grade, and concentration of acetic acid esters. Other compounds undergo concentration owing to physicalchemical effects. In wines whose aging is purely physical-chemical, the reaction most commonly observed is chemical oxidation of the compounds caused by the oxygen in the air. This is true for acetaldehyde, which gradually becomes acetic acid and is in turn esterified with the predominant ethanol. Furthermore, a noticeable concentration of other compounds is observed, due to selective penetration through the wood of the butts.