Changes in red wine composition during bottle aging: impacts of viticultural conditions and oxygen availability

The ongoing climate change implies an increasing mean air temperature, which is signified by weather extremes or sudden changes between drought and local heavy rainfalls. These changing conditions are especially challenging for the established grapevine varieties growing under cool climate conditions due to an increased risk for fungal diseases like downy mildew (DM) and Botrytis bunch rot (BBR) as well as for grape sunburn. To meet that demand, the scope of most grapevine breeding programs is the selection of mildew fungus-resistant and climatic adapted grapevines with balanced, healthy yield and outstanding wine quality.

Sulfur dioxide is widely used during winemaking as an antioxidant and antimicrobial agent. Bisulfite (HSO3−), the predominant form of SO2 at wine pH, reacts with several wine components forming sulfonated adducts.

Extracellular substances (ECS) represent all molecules outside the cytoplasmic membrane, which are not directly anchored to the cell wall of microorganisms living through a planktonic or biofilm phenotype. They are the high-biomolecular-weight secretions from microorganisms (i.e. extracellular polymeric substances – EPS – proteins, polysaccharides, humic acid, nucleic acid), and the products of cellular lysis and hydrolysis of macromolecules. In addition, some high- and low-molecular-weight organic and inorganic matters from environment can also be adsorbed to the EPS. All can be firmly bound to the cell surface, associated with the EPS matrix of biofilm, or released as being freely diffusing throughout the medium.

La présente étude de zonage viticole a été faite dans la région de la vallée Central de Tarija(VCT), dans la ville de Tarija, au Sud de la Bolivie; une région avec plus de 400 années de tradition qui présente une vitiviniculture de haute qualité. La Vallée possède une surface total de 332 milles ha.; existant des vignobles entre 1660 y 2300 m.s.n.m. et dans ce rang d’altitude il existe 91 mille ha.

Clay-based ceramic vessels (jars, pyhtoi, etc.) for wine fermentation and aging processes have been used in several cultures for millennia. This know-how still in practice in several countries of the Armenian highland is gaining worldwide in curiosity, popularity, and interest. Ceramic pots are famous among traditional winemakers for their benefits such as temperature regulation, natural cooling system, favorable oxygen exchange, and impact on pH, which are different from those of stainless steel, wood barrels, or concrete.