Aromatic Characterization of Trepat Grape Pomace Distillates

This study investigates the influence of grape pomace pressing on the chemical composition and sensory characteristics of Trepat grape pomace distillates from two consecutive vintages (2012 and 2013). Distillates obtained from pressed pomace showed higher ethanol strengths than those from unpressed pomace (64% v/v versus 54% v/v) and higher concentrations of several volatile compounds, including methanol, hexanols, aldehydes, and acetate esters. In contrast, distillates from unpressed pomace retained higher levels of terpenes and farnesols. Principal component analysis (PCA) highlighted differences among samples according to both vintage and pomace treatment, reflecting technological and vintage-dependent variability. Pressed pomace distillates contained higher concentrations of fruity and floral acetate esters (2-phenylethyl acetate and 3-methylbutyl acetate) than unpressed pomace distillates; however, sensory evaluation by an expert panel indicated that their fruity expression was often masked by undesirable notes such as rancid and solvent-like aromas. Unpressed distillates tended to be described as more harmonious and mellow and were perceived as having higher overall quality. Although several compounds exceeded their odor activity values (OAV > 1), their potential positive sensory contribution was frequently counterbalanced by elevated concentrations of aldehydes and higher alcohols. Overall, the results indicate that pomace pressing influences the volatile composition of Trepat pomace distillates and may affect sensory balance, suggesting that careful control of pressing conditions could contribute to improving the aromatic quality of grape pomace spirits.