Copigmentation and color of Brazilian Merlot wines I. Influence of skin contact time

Aim : To evaluate the impact of maceration time on color, polyphenols and copigmentation of Merlot wines in order to better understand the differences between two important Brazilian viticultural regions, Campanha Gaucha and Serra Gaucha, which have not been extensively studied. Methods and results : Merlot grapes (red Vitis vinifera variety) from four vineyards located in the Campanha Gaucha (n = 2) and Serra Gaucha (n = 2) regions were harvested, crushed and fermented at the same temperature, with three different maceration times (4, 8 and 15 days). Wines from the 2009 and 2010 harvest were analyzed by spectrometry for phenolic composition and color. The results showed that the origin of the grapes had a higher influence on phenolic composition and color than the winemaking process treatments (i. e., maceration time). Maceration time did not affect copigmentation phenomena, and polymeric anthocyanins had the greatest correlation with color intensity. Conclusion : The maceration time had different effects according to the wines studied. However, more studies will be necessary to identify the characteristics of the grapes and to understand the differences between these two viticultural regions. Significance and impact of the study : One of the regions studied, Campanha Gaucha, is a new Brazilian viticultural region. There are only few studies on this wine region. So, the results presented here will provide some guidance for the selection of the most appropriate oenological practices for this region.