Fruit set rate clonal variation explains yield differences at harvest in Malbec

Aim: Sauvignon blanc displays a range of styles that can include prominent tropical and passionfruit aromas. Both sensory evaluation and chemical analysis have confirmed the above-average presence of ‘varietal thiols’ in the Sauvignon blanc wines from Marlborough, New Zealand.

In partnership with a Bordeaux property wanting to improve the quality of its second wine, the effects of two factors, American oak barrels and mannoproteins were studied. Their impact on the attractiveness and sweetness of wines were characterized during two successive vintages (2012 and 2013). Vinification took place with a homogeneous batch of Cabernet Sauvignon. The wine was then divided up into various groups of five barrels of French and American oak, new or reused. Analyses of volatile and non-volatile wood compounds were undertaken at four months and eight months of wood ageing, by LC-MS and GC-MS.

The northern vineyards produce wines with a high aromatic richness. The wines of Alsace are appreciated for the diversity of their aromas, the typicality of which was for a long time judged mainly according to the grape variety of origin. Alsatian winegrowers have however widely sensed the importance of the environment of the vine on the quality of the wines. Efforts are made to try to harmonize in a reasoned way the interaction between the natural environment and the plant material with a view to developing the character of the grape variety through the fine expression of the terroir and making the quality and typicality even more inimitable. wines produced in Alsace.

Pruning vine-shoots are a viticulture waste that have been traditionally poorly exploited in relation to its chemical minority composition related to phenolic and volatile compounds. In this line, toasted vine-shoots supposes a proposal of enological tool to use to modulate the chemical and sensorial profile of wines. From a phenolic point of view, when vine-shoots are used during winemaking mainly influence to increase the flavanols and stilbenes content, mostly trans-resveratrol, as also an increasing in the sweet tannins and decreasing the green character and total anthocyanins, changing the violet for garnet colour.

Extraction of anthocyanins and tannins have been studied for two grape varieties, Carignan and Grenache, two maturation levels and two vintages, in model solutions and in wines, using UHPLC-MS/MS in the MRM mode  and HPSEC.