Exploring the inner secrets of grapevine: a journey through plant-microbe interactions

One of the consequences of global warming is the quick berry development giving rise to a disconnection between sugar accumulation and the formation of important quality minor compounds such as phenolics and volatile compounds being a huge challenge for the oenologist [1]. Thus, this phenomenon is forcing the search on strategies for maintaining the quality of wines despite this situation. One possibility is to make an early harvest with a low sugar concentration (18ºbrix) and advanced harvest for sparkling wine (20-21ºbrix) and afterwards to combine base wines properly and carry out the second fermentation trying to compensate the lack of secondary metabolites due to the quick berry development and higher alcohol degree of the second one, not adequate itself for sparkling wine. The aim of this study was to assess the chemical and physical characteristics, mainly volatile profile, and foaming properties of sparkling wines from grapes of Chardonnay and Sauvignon blanc.

A soil management and vine irrigation trial was carried out for 4 consecutive years from 2020 to 2023 at agroscope’s experimental vineyard in leytron (Valais, Switzerland) with the Chasselas grape variety (clone 14-33/4, grafted on 5bb). Two types of soil maintenance (bare soil with chemical weeding and sown grass) coupled with two water regimes (with and without drip irrigation from flowering to veraison) were compared in a randomized design with four replicates of 10 vines each.

La pratique de la délimitation des aires des Appellations d’Origine Contrôlées françaises découle de la définition de la notion de terroir en Appellation

The overall quality of aged wines is in part due to the development of complex aromas over a long period (1.) The apparition of this aromatic complexity depends on multiple chemical reactions that include the liberation of odorous compounds from non-odorous precursors. One example of this phenomenon is found in dimethyl sulphide (DMS) which, with its characteristic odor truffle, is a known contributor to the bouquet of premium aged wine bouquet (1). DMS supposedly accumulates during the ten first years of ageing thanks to the hydrolysis of its precursor dimethylsulfoniopropionate (DMSp.) DMSp is a possible secondary by-product from the degradation of S-methylmethionine (SMM), an amino acid iden- tified in grapes (2), which can be metabolized by yeast during alcoholic fermentation.

Grape pomace is the main byproduct generated during wine production and is primarily composed of skins and seeds, which are obtained after the pressing stage [1]. This byproduct retains a significant amount of nutrients, such as fiber, phenolic compounds, unsaturated fatty acids, vitamins, and minerals.