Effect of the contact with fermentation-lees or commercial-lees on the volatile composition of white wines

Wine elaborated from different white Galician varieties (32% Albariño grapes, 15% Treixadura grapes, 12% Loureira grapes, 8.2% Godello grapes and 32.8% Torrontés grapes) was divided in four lots. The wine was vinified traditionally and, after the alcoholic fermentation, the first lot was clarified, and the other three ones have stayed in contact with the natural lees and/or commercial lees. Aromatic composition, after 2 and 7 months, was evaluated by gas chromatographic and organoleptic analysis. Generally, all volatile compounds shown a significant increase after 2 months of contact with the lees, and also after 7 months. In the sensory analysis, the wine tasters rated the intensity of the seven aromatic descriptors (floral, fruity, grass, spice, wood, sulfurous and caramel) for each wine, and the long maturing time rebounds in a decrease of the floral and fruity aromas with respect to the model wine and in an increase in sulphurous character.