The effect of oak wood source, location of seasoning and coopering on the composition of volatile compounds in oak-matured wines

Abstract

The effect of geographical origin and place of seasoning and coopering of oakwood on the concentration of 20 compounds extracted into, or formed in, Chardonnay, Cabernet Sauvignon and model wines during barrel maturation is described. The oak from which the barrels were fabricated was sourced from the Vosges and Limousin regions and the Troncais forest in France, and from Ohio in the USA, and was seasoned in either Australia, France or the USA. Wines matured in Vosges oak barrels contained the highest concentrations of cis and trans-oak lactone and eugenol. The Limousin oak barrels imparted lower levels of cis-oak lactone and eugenol to the wines than did the other French oaks. However, the Limousin-oaked wines were richer in these compounds than the American-oaked wines. These results reflected the previously reported composition profiles of the oak-wood from which the barrels were fabricated. Oak seasoned and coopered in Australia generally imparted more cis-oak lactone, eugenol and the coopering products vanillin and furfural into the wines than did the oak seasoned in France or the USA. Although medium toast had been specified for all barrels, there was considerable variability in the concentration of compounds formed by coopering in the wines. Apparent random microbiological activity in the wines also contributed substantially to variation in wine composition. As a likely result of coopering and microbiological variability, few consistent origin or seasoning effects on the compounds resulting from coopering or microbiological action during oak maturation were observed.