The influence of tertiary and quaternary deposits on the viticultural potential of the terroirs to be found in Geneva, Switzerland

In this video recording of the IVES science meeting 2024, German Puga (Wine Economics Research Centre, School of Economics and Public Policy, University of Adelaide, Adelaide, Australia) speaks about a climatic classification of the world’s wine regions and winegrape variety concentration. This presentation is based on an original article accessible for free on OENO One.

The exploitation of food by-products has garnered significant attention over the past few decades, particularly within the framework of the European Green Deal.

“Sulphites” and mainly sulphur dioxide (SO2) is by far the most widely used additive (E-220/INS 220) in winemaking and likely the most difficult to replace. The well-known antioxidant, antioxidasic and antimicrobial properties of SO2 make this molecule a practically essential tool, not only in winemaking, but also in the production of other food products. The current trend in winemaking is the reduction of this unfriendly additive due to its negative effects on health and environmental. In particular, it could cause headaches and intolerance/allergic reactions in sensitive individuals. Wine is considered one of the major contributors of exposure of SO2 in the adult population, when this beverage is included in the diet.

Vine water status was measured on 96 plots of three vines inside a vineyard block of 0.28 ha during three years: 2003, 2004 and 2005. Three physiological indicators were implemented: stem water potential, carbon isotope discrimination measured on grape sugars at ripeness (δ13C) and canopy temperature measured by high resolution remote sensing. For stem water potential, measurements were taken on every single vine of each plot.

Prior to winemaking, organic or mineral nitrogen compound concentrations are usually measured in the vineyard and in grape musts. These indicators facilitate vine cultivation decisions, usually through yield or vigor. During vinification, yeast and bacteria metabolize nitrogen compounds in the musts in order to generate biomass. After fermentation, the microorganisms rerelease a part of this nitrogen as soluble compounds into the wines. Another part remains bound in the lees and can be lost during racking. The must’s natural nitrogen quantities, additional supplements during fermentation, and lees contact management enhance the release of nitrogen compounds to the wines. During ageing these nitrogen compounds – primarily the amino acids – are implicated in the generation of odorous compounds such as heterocycles(1).