During wine conservation in a bottle, the control of oxygen transfer from the outside environment to the wine inside the bottle is a key parameter that determines the wine quality. Many other factors can also influence the evolution of wine during postbottling aging,
S’il n’existe pas de réglementation officielle, la démarche des vins naturels prône un retour aux pratiques dites ancestrales préconisant notamment un mode d’élaboration des vins utilisant le moins d’intrants possible. Le seul autorisé reste l’anhydride sulfureux (SO2) à des doses quatre à cinq fois moins importantes que pour les vins dits conventionnels. Ce désir de renouer avec
loss and color browning which lead to wine unacceptance by consumers. These changes are mainly driven by the consumption of oxygen by polyphenols leading to the production of quinones which are oxidant compounds. Quinones can react with numerous nucleophilic compounds notably aromatic thiols, decreasing the aromatic bouquet of the wine.
Wine longevity is a complex multifactor phenomenon in which the weight of the different factors is not well known. One of the key factors of wine longevity is related to its resistance to oxidation. This property can be defined as the ability of the wine, under an exposure to oxygen, to keep its color, avoid accumulation of acetaldehyde and Strecker aldehydes (SA), and keep as long as
In the course of this study, stabilisation (lees stirring in unclarified must) with skin contact and classic white wine vinification were compared for the Sauvignon blanc and Traminer varieties in Austria. The test wines were analysed for the volatile substances esters, free monoterpenes and fruity thiols
Fermenting grape juice represents one of the oldest continuously maintained anthropogenic microbial environments and supports a well-mapped microbial ecosystem. Several yeast and bacterial species dominate this ecosystem, and some of these species are part of the globally most studied and best understood individual organisms. Detailed physiological, cellular and molecular data have been generated on these individual species and have helped elucidate complex evolutionary processes such as the domestication of wine yeast strains of the species Saccharomyces cerevisiae. These data support the notion that the wine making environment represents an ecological niche of significant evolutionary relevance. Taken together, the data suggest that the wine fermentation ecosystem is an excellent model to study fundamental questions about the working of microbial ecosystems and on the impact of biotic selection pressures on microbial ecosystem functioning. Indeed, and although well mapped, the rules and molecular mechanisms that govern the interactions between microbial species within this, and other, ecosystems remain underexplored. Here we present data derived from several converging approaches, including microbiome data of spontaneous fermentations, the population dynamics of constructed consortia, the application of biotic selection pressures in directed laboratory evolution, and the physiological and molecular analysis of pairwise and higher order interactions between yeast species. The data reveal the importance of cell wall-related elements in interspecies interactions and in evolutionary adaptation and suggest that predictive modelling and biotechnological control of the wine ecosystem during fermentation are promising strategies for wine making in future.
We tried to give a part of the answer to this question by monitoring glutathione during winemaking and storage. The novelty of our approach is to quantify simultaneously the three known forms of glutathione: free glutathione (GSH), oxidized form (GSSG) and glutathione-S-sulfonate (GSSO3H).
Since the 18th century, sulfur dioxide (SO2) is used in winemaking. Added at different steps, its antimicrobial but also antioxidasic and antioxidant properties are very helpful for winemakers. Nevertheless sulfur dioxide has a real potential health impact, particularly for sensitive consumers often highlighted by hygienists. Nowadays, a serious trend for “natural” wines (i.e. produced without any additives), as described by their producers, could be observed on the French market what match with a proliferation of wines elaborated without any sulfite addition.