Piloting grape ripening in a global warming scenario: feasible techniques are available

Biofilms are sessile microbial communities whose lifestyle confers specific properties. They can be defined as a structured community of bacterial cells enclosed in a self-produced polymeric matrix and adherent to a surface and considered as a method of immobilisation. Immobilised microorganisms offer many advantages for industrial processes in the production of alcoholic beverages and specially increasing cell densities for a better management of fermentation rates.

Grapes’ sun-drying is one of the most critical steps in the production of ‘Commandaria’, a dessert wine with Protected Designation of Origin that is exclusively produced in Cyprus from grapes of the two indigenous cultivars (Vitis vinifera L.), namely ‘Mavro’ and ‘Xynisteri’. Despite its significant economic importance, no data regarding the primary and secondary metabolites of the aforementioned cultivars exist.

Intra-vineyard variation grape berry ripening occurs within bunches, between bunches on the same vine and between vines. Although it is assumed that such variation also occurs at the grape berry cell wall level, no study to data has investigated in any depth. Here we have used a intra-vineyard panel design to investigate pooled bunches from six vines (per panel) in the context of a winemaking scenario. The dissected vineyard was harvested by separate panels, where each panel was then subjected to a standard winemaking procedure with or without the addition of three different enzyme preparations for maceration.

Des expérimentations sur Gamay ont été réalisées en Beaujolais de 2000 à 2006 sur 10 parcelles d’AOC différentes. De nombreuses mesures ont été effectuées à différents stades (vigne, baies récoltées, vinification et bouteille avec ou sans vieillissement). Ces mesures sont également de natures différentes (données phénologiques, analytiques, dégustation). Des analyses de la composition des sols sont également disponibles.

Astringency is a crucial sensory attribute typically described as the drying and/or puckering sensation occurring after the consumption of tannin-rich foods and beverages. In this study, thirty-seven red wines from different varieties, origins and styles were evaluated, analyzing both chemical and sensory features. Principal Component Analysis was used for dimensionality-reduction and for correlating selected chemical parameters against astringency. The results showed that tannin content was the most important chemical parameter influencing overall astringency but more clearly the dryness sub-quality, followed by pH, titratable acidity and alcohol content.