Criteria to discriminate between wines aged in oak barrels and macerated with oak fragments

Abstract

Wine aging in barrels is carried out to increase stability and achieve more complex aromas. In the last few years, however, the practice of macerating wine with small fragments of toasted oak (chips) has become increasingly common. This conveys similar tastes, aromas, and wooden notes to the wine as those obtained with traditional barrel aging, but much faster and at a fraction of the cost. Without proper regulation, this could lead to fraud if wine macerated with chips is offered as barrel aged wine.

In the present study, 75 volatile compounds have been determined by applying gas chromatography–mass spectrometry (MS) and flame ionization detection (FID). It has been found that compounds directly related to the wood have greater discriminative power for telling apart wines aged in barrels from those macerated with oak fragments, but no single compound permits flawless classification. Therefore, we have studied the effect of the addition of oak fragments of different origins, different oak types, different formats and subjected to different toasting processes on a set of 231 samples from 6 Spanish Denominations of Origin wines (DOs), and compared them to those same wines aged in oak barrels. In light of the results, we have developed a set of criteria which allows distinguishing with high degree of accuracy between wines which have been aged in barrels and those macerated with oak fragments. The application of these criteria to different wines allows correct classification in over 90% of cases.