New acacia gums fractions: how their features affect the foamability of sparkling base wines?

Dans la région des Coteaux du Layon, en Maine et Loire, l’effet terroir et son déterminisme sont étudiés dans le cadre de la production des vins liquoreux.
Ces vins sont le résultat d’une maturité poussée au delà de celle prévue par la nature afin de donner aux baies une teneur en sucre et en matière sèche très forte, pour mieux valoriser ces effets de la surmaturation, les baies sont récoltées selon la méthode des tries successives (Asselin et al, 1996). Ainsi, on ne récolte à chaque passage que les grains ayant atteint le niveau de concentration requis pour obtenir des vins à fort degré d’alcool avec des sucres résiduels.

The microbial diversity during spontaneous grape must fermentation has a determinant influence on the chemical composition and sensory properties of wine. Therefore, yeast diversity is an important target to better understand wine regionality. Hence, the aim of this study was to isolate, identify, and characterize the yeast core microbiota in grape must during the early stage of lab-scale spontaneous fermentation of withered grapes to produce Amarone della Valpolicella wine (Verona, Italy).

Table grape production requires adequate nitrogen (N) supply to sustain vine performance and obtain high yields. However, excess agricultural N fertilization is a major source of groundwater contamination and air pollution. Therefore, there is a strong need for empirically based precision N fertilization schemes in vineyards, for optimizing grape yield and quality while minimizing their environmental impact.
Our aim was to unequivocally quantify table grape N requirements, elucidate the drivers of daily N uptake, and quantify the relationship between fertigation N levels and vine growth, fruit yield, composition, and quality. For this, forty ‘Early Sweet’ (early-maturing, white) and ‘Crimson seedless’ (late-maturing, red) vines were grown in 500L drainage-lysimeters for 2 fruiting seasons, while subjected to five continuous N fertigation treatments ranging from 10 to 200 ppm.

In grafted plants, such as grapevine, increasing the diversity of rootstocks available to growers is an ideal strategy to get adaptation to climate change. The rootstocks used for grapevine are hybrids of various American Vitis, including V. berlandieri. The rootstocks currently used in vineyards are derived from breeding programs involving very small numbers of parental individuals.

The aim of this work was to reduce the alcohol content of Tempranillo wine. Tempranillo wines were produced by grapes harvested at different ripening dates (August 11 which was 21 oBrix and September 28 with 25 oBrix). At the second date, the Tempranillo wines were elaborated as follows: grapes were destemmed, crushed and collected into 50 L stainless-steel vats. Before preferementative maceration in cold, 50 % (M1) and 70 % (M2) of the must have been replaced by the same percentage of must from the first harvest. In addition, a control wine (C) was performed with only grapes from the second harvest.