Understanding calcium tartrate precipitation in wines: A comprehensive study from soil and grapevine to stabilisation strategies before bottling

Calcium (Ca2+) plays a pivotal dual role in grapevine physiology, acting both as a structural element essential for cell wall integrity and membrane stability, and as a secondary messenger regulating plant growth and stress responses. Calcium accumulation in grape berries significantly affects composition and wine chemistry, influencing one of the most complex forms of wine instability: calcium tartrate (CaT) precipitation. CaT instability remains difficult to predict due to its slow crystallisation kinetics, delayed precipitation onset, and the complex interactions among calcium, tartaric acid, and the various components of the wine matrix. This review integrates past and current findings from soil science, plant physiology, berry development, and wine chemistry (integrated “vineyard → winery” approach) to provide a comprehensive overview of Ca2+ dynamics from vineyard to bottle. Key agronomic factors, including soil composition, active limestone content, rootstock selection, irrigation strategies, and climate change, are explored for their influence on calcium uptake and distribution within grape tissues. At the oenological level, this review analyses the main biochemical and physicochemical factors influencing CaT precipitation, including pH, ethanol, organic acids, phenolic compounds, and macromolecules such as grape-derived polysaccharides and mannoproteins. It further evaluates both traditional and innovative stabilisation strategies, such as cold treatment, electrodialysis, ion-exchange resins, and protective colloids, assessing their effectiveness and impact on wine quality. Finally, it highlights existing knowledge gaps and emphasises the need for an integrated vineyard-to-winery approach to develop predictive models (e.g., Calcium Tartrate Risk Index) and optimise stabilisation techniques, ensuring wine stability and preserving sensory quality under changing climatic conditions.