Environmental characteristics and weather impact yeast populations and their dynamics in spontaneous fermentations.

Winemaking is influenced by many factors, from the vineyard to the fermentation process. While traditional approaches have focused on vineyard treatments and controlled fermentations to ensure a stable product, global warming has made it necessary to reassess the effects of these factors on winemaking. This study aimed to evaluate the impact of vintage, management, and environmental settings on the composition of yeast populations driving grape spontaneous fermentations and defining the characteristics of the final product. Our results emphasize how climate change and the vineyard's yeast populations influence fermentation, showing that while the vintage plays a key role in grape composition, it s not the sole determinant of fermentation. The geographical location of the vineyard, alongside the management practices and vintage, shapes the composition and dynamics of yeast populations. Specific vineyard conditions sometimes lead to stable and unique yeast populations. Furthermore, the grape origin affects both the yeast population and the wine's volatile compounds, with certain yeast species, like Saccharomyces cerevisiae, being linked to specific environmental features. While vintage and climate change impact a smaller portion of the yeast population, the environment remains a significant influence. As fermentation progresses, the yeast populations retain vineyard-specific characteristics, underlining the strong connection between yeast dynamics and environmental factors. Understanding these interactions is crucial for adapting to global warming and optimizing wine fermentation processes. It will help improve wine quality, innovation, and specific wine characteristics through better management of microbial communities in the grape-wine ecosystem.