Alginic acid as a novel strategy for calcium tartrate stabilization in wines

Abstract

Calcium tartrate (CaT) instability is an increasingly relevant issue in bottled wines, mainly due to increasing calcium concentrations associated with climate change and certain winemaking practices. Unlike potassium hydrogen tartrate instability (KHT), CaT precipitation is a slow and difficult-to-predict phenomenon that often occurs after bottling and is not effectively prevented by traditional cold stabilization. Therefore, identifying new stabilizing agents is of significant interest. This study evaluated, the potential use of alginic acid as a new stabilizer to prevent CaT precipitation in wines, and its performance was compared with authorized stabilizers such as carboxymethylcellulose (CMC) and potassium polyaspartate [1]. The effectiveness of these additives was assessed by monitoring calcium tartrate precipitation through induced nucleation methods and by measuring changes in calcium concentration after treatment [2]. Alginic acid showed a better calcium stabilizer capacity compared with CMC, leading to a greater reduction in CaT precipitation and shifting most of the tested wines into the stability zone. Although the higher applied dose of alginic acid (300 mg/L) relative to CMC (200 mg/L) may have contributed to this effect, its enhanced performance is likely related to its strong anionic character, higher charge density, and pronounced affinity for calcium ions. These properties promote calcium complexation and reduce supersaturation. Contrary to previous concerns, potassium polyaspartate did not increase CaT instability in either stable or unstable wines. Instead, it showed a stabilizing performance comparable to that of CMC. These findings suggest that alginic acid represents a promising clean-label alternative for CaT stabilization, particularly given its regulatory authorization as a processing aid in winemaking. However, the results reflect only short-term stabilization effects. Further research is required to assess its long-term stabilization capacity, optimize application doses according to the initial level of instability, and evaluate potential impacts on the sensory characteristics of treated wines [3].

References

1. OIV. International Code of Oenological Practices; International Organization of Vine and Wine: Paris, France, 2025.
2. Abguéguen, O., Boulton, R. B. (1993). The crystallization kinetics of calcium tartrate from model solutions and wines. Am. J. Enol. Vitic., 44(1), 65–75.
3. Cosme, F., Filipe-Ribeiro, L., Coixão, A., Bezerra, M., Nunes, F. M. (2024). Efficiency of alginic acid, sodium carboxymethylcellulose, and potassium polyaspartate as calcium tartrate stabilizers in wines. Foods, 13(12), 1880.

Funding

Project Vine&Wine Portugal—Driving Sustainable Growth Through Smart Innovation, Application n° C644866286-00000011, co-financed in the scope of the Mobilizing Agendas for Business Innovation, under Reg. (EU) 2021/241, in the Plano de Recuperação e Resiliência (PRR) to Portugal, na sua componente 5 – Capitalização e Inovação.