Studies on the Mechanism of Aging of Distilled Liquors

Since the aging process of distilled liquors is regarded as the result of extraction of phenolic components from wooden barrel, the authors carried out the fractionation of the alcohol extract of oak wooden chips and examined the effect of the resultant fraction on whisky or brandy.

A top fraction which was obtained by means of the method of silicic acid column chromatography developed a similar flavor to the aging flavor of distilled liquors when it was warmed with raw distilled liquor. The fraction contained phenolic components such as syringic and vanillic acidlike substances and unknown polyphenolic compounds. The authors suggested that these substances in the top fraction are concerned with the development of aging flavor. On the other hand, gallic acid was found from the other fraction.