Despite being natural phenomena of physical-chemical stabilization of young wines, tartrate precipitations in bottled wines are often understood as a quality fault. Carboxymethylcellulose (CMC) is an inhibitor of tartaric salts crystallization, authorized as oenological additive, which application is currently limited to white and sparkling wines by OIV. The aim of this exploratory research was to study the effect of different CMC on a (tartaric) unstable red wine, in terms of tartrate stability, colouring matter stability, turbidity, comprehensive phenolic composition, and chromatic characteristics. All the CMC tested were able to inhibit potassium bitartrate crystallization in the red wine, promoting its tartaric stability. Slight increase in the colour intensity, coloured anthocyanins concentration, and turbidity of the wine were observed. No colouring matter precipitation was verified. The study seems to indicate that the CMC can be an efficient alternative to other tartaric stabilization treatments, also in red wines, opening new prospective and scenarios concerning the use of CMC in this type of wines.