Resumen de Effect of ageing system and time on the quality of wine brandy aged at industrial-scale
S. Cruz, Sara Canas, A. Pedro Belchior
During the fi rst six months of ageing it was performed the analysis of dissolved oxygen, dry extract, total polyphenol index, chromatic characteristics and low molecular weight compounds of Lourinhã brandies aged in different systems: 650 L wooden barrels (traditional system) and stainless steel tanks of 3000 L with wood staves (alternative system). In each system two kinds of wood were used simultaneously and arranged alternately: Portuguese chestnut (Castanea sativa Mill.) and Limousin French oak (Quercus robur L.) with medium plus toasting level. The quantity of staves was calculated in order to reproduce the surface/volume ratio of a 650 L wooden barrel. The results obtained show that the ageing system has a very signifi cant effect on the chemical composition and colour of the aged brandies. The alternative system promotes further evolution of colour and lower oxygen consumption, while the traditional system yields higher dry extract, total phenolic and low molecular weight compounds contents. These outcomes, which have been proven by an essay based on the dry extract method, indicate that the changes observed in the brandy during the ageing process are closely related to the ageing system, suggesting that the constituents and the phenomena that occur in each one are different. Regarding the ageing time, there is a highly signifi cant effect on the characteristics of the aged brandies, even though the observations are made in a short period of time (minimum requested by the European legislation for the ageing of the wine brandy), with higher extraction of the wood compounds up to 90 days.
