The objective this work has been study the possibility of partially or completely replacing sulphur in the winemaking of white wines through the use of the prefermentative saturation of musts with CO2. Three types of wines were made from the same Airén and Chardonnay must and under the same conditions: Control wine, reduction of SO2 in half and total reduction of SO2.
No technologically important variations in the usual oenological parameters were observed in freshly bottled wines by saturating the musts with CO2 and decreasing SO2 doses. In terms of color, it should be noted that all wines of both varieties had similar values of luminosity and that the saturation of musts with CO2 produced wines with more green tones and the decrease in doses of SO2 with more yellow notes. In relation to volatile composition, the saturation of musts with CO2 and the reduction of SO2 doses produced wines with higher concentrations of compounds responsible for fruity and floral notes. At the sensory level, the results of volatile analysis were corroborated and both trained tasters and consumers positively valued the wines. Microbial stability and colour were monitored for 12 months, a normal marketing period for young wines, with the following conclusions obtained:
Signs of malolactic fermentation were observed in wines without SO2. However, wines with low doses of SO2 remained perfectly stable. With regard to color after 12 months the wines of both varieties evolve in a favorable way, a slightly more intense color, but no notes of oxidation are seen. Effective control of acetic acid bacteria over time has been proven as the volatile acidity of these wines is similar to that of control wines and does not increase the year of bottling.
Authors: P.M. Izquierdo Cañas1*, S. Guri Baiget2, E. García Romero1, V. Cejudo Martín de Almagro2, J. Mallen Pomes2
1 Instituto Regional de Investigación y Desarrollo Agroalimentario y Forestal de Castilla-La Mancha (IRIAF), IVICAM, Ctra. Albacete s/n, 13700 Tomelloso, Ciudad Real, Spain.
2 Carburos Metálicos S. A.- Air Products Group. Avda de la Fama 1, 08940 Cornellà de Llobregat, Barcelona, Spain.