Specificities of red wines without sulfites: which role for acetaldehyde and diacetyl? A compositional and sensory approach.

Despite their significant impact on wine quality and stability, colloids in red wine remain relatively under-researched. A series of studies, developed in the context of the d-wines project, aimed to provide a comprehensive understanding of the structure, composition, and formation mechanisms of red wine colloids by studying monovarietal wines from 10 of the most significant Italian red grape varieties. Starting from the idea that proteins, polysaccharides, and tannins should be involved in colloid formation, 110 monovarietal red wines were analysed for these components, revealing high inter- and intra-varietal diversity [1].

A rapid and reproducible microwave (MW)-assisted acid digestion protocol was developed to determine the elemental composition of grapevine bark samples using ICP-MS.

Agriculture, natural resource management and the production and sale of products such as wine are increasingly data-driven activities. Thus, the use of remote and proximal crop and soil sensors to aid management decisions is becoming commonplace and ‘Agtech’ is proliferating commercially; mapping, underpinned by geographical information systems and complex methods of spatial analysis, is widely used. Likewise, the chemical and sensory analysis of wines draws on multivariate statistics; the efficient winery intake of grapes, subsequent production of wines and their delivery to markets relies on logistics; whilst the sales and marketing of wines is increasingly driven by artificial intelligence linked to the recorded purchasing behaviour of consumers. In brief, there is data everywhere!

Opinions will vary on whether these developments are a good thing. Those concerned with the ‘mystique’ of wine, or the historical aspects of terroir and its preservation, may find them confronting. In contrast, they offer an opportunity to those interested in the biophysical elements of terroir, and efforts aimed at better understanding how these impact on vineyard performance and the sensory attributes of resultant wines. At the previous Terroir Congress, we demonstrated the potential of analytical methods used at the within-vineyard scale in the development of Precision Viticulture, in contributing to a quantitative understanding of regional terroir. For this conference, we take this approach forward with examples from contrasting locations in both the northern and southern hemispheres. We show how, by focussing on the vineyards within winegrowing regions, as opposed to all of the land within those regions, we might move towards a more robust terroir zoning than one derived from a mixture of history, thematic mapping, heuristics and the whims of marketers. Aside from providing improved understanding by underpinning terroir with data, such methods should also promote improved management of the entire wine value chain.

Residual grape solids (suspended particles) in white and rosé musts vary depending on the clarification pro-cess. These suspended solids contain lipids (more especially phytosterols) that are essential for yeast meta-bolism and viability during fermentation in anaerobic conditions.

G.r.a.s.p.o. Is not only the acronym for gruppo di ricerca per la salvaguardia e preservazione dell’originalità viticola di ogni territorio (‘research group for the safeguard and preservation of the originality of every territory’s grapes’), and is not just the italian synonym for ‘raspo’ (‘peduncle’) as treccani dictionary mentions: in the veneto dialect it is the whole bunch of grapes.