In this paper an innovative measurement system for odor classifi-cation, based on Quartz Crystal Microbalances (QCMs), is pre-sented. In particular, the problem of detecting typical wine aroma components in mixtures where ethanol is present is taken into ac-count. In QCM sensors the sensitive layer is a polymeric layer de-posited on a quartz surface. Chemical mixtures are adsorbed by the polymeric layer, inducing a change in the quartz mass and there-fore in its resonance frequency. The frequency shift is measured by a dedicated fully digital front-end hardware implementing a tech-nique proposed by Cantoni [1]. This approach allows reducing the measurement time while maintaining a high frequency resolution. The developed system allows measuring variations of the QCM resonance frequency shifts during chemical transients obtained with abrupt changes in odor concentration. Hence the reaction ki-netics can be exploited to differentiate among different compounds. In this study some measurements obtained with an array of 4 sen-sors with different sensitive layers are presented. An exponential fitting of the transient responses is used for feature extraction. Principal Component Analysis (PCA) to reduce data dimensionality is used.