The quality of wine depends on several factors being their phenolic composition one of the most important ones. Phenolic compounds contribute to the organoleptic characteristics of wine such as color, astringency, and bitterness. Grape skins and seeds are the main sources of tannins. Despite the large number of studies carried out since 1960s an important question remains: what factors influence the biosynthesis, the quantity, and the distribution of tannins in grape seeds and how can winemaking processes impact the extractability of seed tannins in wine?
Combining rootstocks and deficit irrigation techniques to maintain vineyard sustainability under semiarid and water limiting conditions
This post reports a study carried out to find an approach to improve vine performance and enhance Monastrell vineyard sustainability under semiarid and water limiting conditions. Regulated deficit irrigation (RDI) and partial root zone irrigation (PRI) were compared for five years, in field-grown mature Monastrell grapevines grafted on five different rootstocks (140Ru, 1103 P, 41B, 110R, and 161-49C), in the semiarid winegrowing region.
What percentage of cork should a cork-based stopper have from a mechanical perspective?
Wine bottles are sealed with cylindrical stoppers, this post reports to a study aimed to compare the mechanical behaviour of natural cork stoppers, micro-agglomerated cork stoppers and co-extruded synthetic closures. Different tests were carried out to simulate bottling procedure, the beginning of the sealing period and the extraction process. Cork percentage by itself provides insufficient information on the mechanical behaviour of a cork-based stopper. The best indicator of the micro-agglomerated cork stopper mechanical behaviour is cork percentage together with stopper density. Data also show that mechanical behavior depends more on cork content than on binder content. These results highlight the versatility of cork-based stoppers from a mechanical perspective.
Pulsed electric fields accelerate release of mannoproteins from Saccharomyces cerevisiae during aging on the lees of Chardonnay wine
The integrity and morphology of Saccharomyces cerevisiae is sustained by the cell wall, the target of the main microbial inactivation processes. One promising approach to inactivation is based on the use of pulsed electric fields (PEF). This post relates a study where the potential of PEF for triggering autolysis of Saccharomyces cerevisiae and accelerating the release of mannoproteins during aging on the lees of Chardonnay wine was evaluated. The result obtained demonstrates that PEF permits the acceleration of the aging-on-lees step while avoiding or reducing the problems associated with it. To achieve this effect, intense treatment is not required. Therefore, wineries could process lees by using the most economical PEF devices on the market.