Terroir aspects of harvest timing in a cool climate wine region: physiology, berry skin phenolic composition and wine quality

Abstract

Preliminary experiment of harvest timing was carried out in Eger wine district, Hungary in 2009. In situ physiologicalresponses, berry quality parameters and wine quality of the Kékfrankos grapevine were studied at two growing sites(Eger-K6lyuktet6 – non-stressed, flat vineyard, and Eger-Nagyeged hill – water stressed, steep slope vineyard). At the hilly site physiological responses indicated mild to moderate water stress, especially during the ripening period. In contrast, nowater deficit was detected at Eger-K6lyuktet6. Sugar concentration was increasing during the ripening at both sites having higher values at the water stressed vineyard. Total polyphenol, catechin and anthocyanin concentration of the berry skin was increasing significantly at Eger-Nagyeged hill until the last harvest date. In contrast, no changes were found in these parameters in the case of the non-stressed site. Wine phenolic composition and sensorial characteristics (quality and style) were alsochanging during the ripening. Wine analysis has shown that the water stressed site has a greater phenolic potential for quality wine making. In conclusion, differences in grape ripening dynamic of the terroirs resulted in different optimal harvest time at both sites. The correlation was also different between the concentration of primary parameters and phenolics at the two sites.This suggests that new tools should be developed and applied to determine optimal ripeness. New methods would helpnot only to asses the quality of the grape, but wine style could also be predicted by harvest timing.