The use of viticultural and oenological performance of grapevines to identify terroirs: the example of Sauvignon blanc in Stellenbosch

Must fermentation is a complex process influenced by various factors, especially microbiological activities. The characteristics and quality of the resulting wine are closely linked to the stages that unfold throughout this progression.

Nitrogen (N) fertilizer is important for grape growth and the quality of wine. It is essential to address the mismatch between N application and wine composition. Cabernet Gernischt (Vitis vinifera L.), as one of the main wine-grape cultivars in China, was introduced to Yantai wine region in 1892. This grape cultivar is traditionally used for quality dry red wine with fruit, spices aroma, ruby red and full-bodied wines. In order to regulate vine growth and improve grape and wine quality, Cabernet Gernischt grapevines were subjected to decreased levels of N treatments, compared to normal N supply treatment, during grape growing seasons of 2019 and 2020.

The bioprotection of musts or grapes is a strategy for limiting sulfiting during winemaking and more specifically at pre-fermentative step. The most preconized yeasts in bioprotection mainly belong to Metschnikowia pulcherrima and Torulaspora delbrueckii species. While previous studies have demonstrated that bioprotectant non-Saccharomyces strains were able to protect musts and wines against microbial spoilage as well as sulfites, they cannot protect must against oxidation which appears to be the main limit of this practice.

Viticulture and oenology face two major challenges today, climate change and the reduction in the use of inputs. Climate change induces low acidity and microbiologically less stable wines

Grapevine vegetative multiplication allows the accumulation of spontaneous mutations and increase intra-cultivar genetic diversity that can be exploited to maintain grape wine quality