Influence of the different cork stoppers and sulfur dose in champagne quality

‘Mavrodafni’ (Vitis vinifera L.) is considered one of the oldest grapevine cultivars indigenous to the Greek vineyard, with western Peloponnese being its primary center of cultivation. ‘Renio’ is considered to be either a variant of ‘Mavrodafni’ or an altogether different cultivar. Both ‘Mavrodafni’ and ‘Renio’ can be found in the vineyards of the centers of cultivation, since ‘Renio’ is considered to be more productive compared to ‘Mavrodafni’, and for this reason, it has gradually replaced ‘Mavrodafni’ from cultivation over the course of time. The aim of the present study was to assay the mechanical properties, the polyphenolic content and the antioxidant capacity of skin extracts and must of berries coming from ‘Mavrodafni’ and ‘Renio’, cultivated in the same vineyard as well as in the different regions of cultivation of the PDO Mavrodafni Patras.

Wine quality is influenced by grape maturity, typically monitored by measuring sugar content and acidity.

Over the last years, the potential use of non-Saccharomyces yeasts to modulate the production of target metabolites of oenological interest has been well recognized. Among non-Saccharomyces yeasts, Starmerella bacillaris (synonym Candida zemplinina) is considered one of the most promising species to satisfy modern market and consumers preferences due to its peculiar characteristic (enhance glycerol and total acidity contents and reduce ethanol production). Mixed fermentations using Starm. bacillaris and Saccharomyces cerevisiae starter cultures represent a way to modulate metabolites of enological interest, taking advantage of the phenotypic specificities of the former and the ability of the latter to complete the alcoholic fermentation. However, the consumption of nutrients by these species and their produced metabolites may inhibit or stimulate the growth (and malolactic activity) of lactic acid bacteria (LAB).

The yeast ecosystem in grape musts is quite broad and depends on the region and the health of the grapes. Within this, there are yeasts that can generate fermentative deviations and/or cause defects in the wine. It is very important to address this issue because there are significant economic losses in the wine industry when the fermentation process and/or the organoleptic characteristics of the wine are negatively affected, even more today since climate change has a marked effect on the composition of this ecosystem. The aim of this work is to characterize the behavior regarding detrimental oenological features of potential spoilage yeasts isolated from viticultural environments.

During wine aging many compositional changes take place. In particular, aroma undergoes dramatic modifications through a wide range of reactions that to date are only partly understood. Italy owns one of the largest ampelographic heritages worldwide, with over three-hundred different varieties. Among these, many white grapes are employed for the production of dry still white wines. Some of these wines are consumed young while others are more prone to aging. For many of these wines, the aging patterns related to volatile composition are still unknown.