Aging In Oak Barrels Research Articles

Changes in Some Volatile Constituents of Brandy During Aging

Several kinds of experimental brandies, both unaged and aged in various types of U.S. and French oak barrels, were vacuum distilled, the components in the distillate were extracted with ether-pentane (2:1), and concentrated to small volume by removal of the solvent for gas chromatographic analyses with a Carbowax 20M column. Quantitative levels were estimated by comparing peak areas with those of an internal standard, 1-octanol. Acetate esters of isoamyl, <i>n</i>-hexyl, and β-phenethyl alcohols decreased during aging in oak barrels. The ethyl esters of the fatty acids, caproic, caprylic and capric, increased during aging while ethyl laurate changed little or slightly decreased. Compounds derived mostly or entirely from oak, furfural, 5-methyl furfural, diethyl succinate and the <i>cis</i> and <i>trans</i> isomers of β-methyl-γ-octalactone (oak lactones -a and -b), were more abundant in brandies aged in U.S. oak than in French oak and lesser amounts of oak-derived compounds were obtained in brandies from reused barrels.