Comparative studies on the dynamics of fermentation of selected wine yeasts

Initial results are presented of research into the relationship between climate variability and viticulture in New Zealand vineyards. Atmospheric modelling and analytical tools are being developed to improve adaptation of viticultural practices and grape varieties to current and future climate.

Grapevine (Vitis spp.) is a globally significant fruit crop and enhancing its agronomic and oenological traits is crucial to meet changing agricultural conditions and consumer demands.

Riesling represents the most widely cultivated grape variety in Germany and is therefore of particular economic interest. During recent years an increase in the petrol-note as well as in undesirable bitter and adstringent notes has been reported. These changes are most likely linked to increasing temperature and sunlight exposure of grapes due to climate changes.
The “petrol note” is caused by the formation of the C13-norisoprenoid 1,1,6-trimethyl-1,2-dihydronaphthalin (TDN), which originates from acid-labile precursors formed by the carotenoid degradation in the grape.

Climate change has a strong impact on the earlier onset of important phenological stages and plant development in viticulture.

In this work, these four red varieties were characterized in terms of phenolic composition. Thus, the anthocyanin accumulation and the extractability evolution during ripening were compared.