Inoculation of grape musts with single strains of Saccharomyces cerevisiae yeast reduces the diversity of chemical profiles of wines

Abstract

Anecdotal evidence suggests that spontaneous alcoholic fermentation of grape juice is becoming a more popular option in global wine production. Wines produced from the same grape juice by inoculation or spontaneous fermentation usually present distinct chemical and sensorial profiles. Inoculation has been associated with more similar end-products, a loss of typicity, and lower aroma complexity, and it has been suggested that this may be linked to suppression of the local or regional wine microbial ecosystems responsible for spontaneous fermentations. However, whether inoculated fermentations of different juices from different regions really end up with a narrower, less diverse chemical profile than those of spontaneously fermented juices has never been properly investigated. To address this question, we used grape juice from three different varieties, Grüner Veltliner (white), Zweigelt (red), and Pinot noir (red), originating from different regions in Austria to compare spontaneous and single active dry yeast strains inoculated fermentations of the same grape samples. The chemical analysis covered primary metabolites such as glycerol, ethanol and organic acids, and volatile secondary metabolites, including more than 40 major and minor esters, as well as higher alcohols and volatile fatty acids, allowing an in depth statistical evaluation of differences between fermentation strategies. The fungal (mainly yeast) communities throughout fermentations were monitored using automated ribosomal intergenic spacer analysis. The data provide evidence that inoculation with single active dry yeast strains limits the diversity of the chemical fingerprints. The fungal community profiles clearly show that inoculation had an effect on fermentation dynamics and resulted in chemically less diverse wines.

Survey of Inoculated Commercial Saccharomyces cerevisiae in Winery-Based Trials

“…On the contrary, for modality 4, the ADY V added at the beginning of fermentation seemed to dominate, as no ADY F profile was detected during fermentation and a lower number of native yeasts were also detected. Several works have already shown that the inoculum of S. cerevisiae ADY cells, both commercial and indigenous, ensures a very rapid dominance of a single strain and the suppression of natural microbiota [23][24][25].…”

Multi-omics framework to reveal the molecular determinants of fermentation performance in wine yeast populations

“…Yeast communities play crucial roles in determining the chemical and sensory properties of the resulting wines [2][3][4]. A diverse yeast microbiome in grape musts can enhance the aromatic complexity of final wines [5][6][7][8]. The inherent diversity in grape musts, coupled with the spontaneous nature of fermentations, implies limited control over population dynamics during wine fermentation, influencing its kinetics and final sensory output.…”

Fungal dynamic during apricot wine spontaneous fermentation and aromatic characteristics of Pichia kudriavzevii for potential as starter

“…Attributing to the cheapness and ready implement of spontaneous methods, researchers seek to enhance the fermented foods of flavour complexity and specificity via spontaneous fermentation, implemented across the whole fermented beverage production chain ( Luzzini et al, 2021 , Philipp et al, 2021 ), but not yet in the production of apricot wines. In addition, microbial activity was substantially correlated with the spontaneous fermentation process, of which indigenous microbiota (mainly yeast populations) is likely the primary driver of these fermented beverages production ( Varela, 2016 ).…”