The use of cation exchange in acid cycle to obtain tartrate stability of red wine was evaluated within the limits specified by the Office International de la Vigne et du Vin (OIV). Unstable red wines submitted or not to a previous cold treatment were used in the experiment. A portion of each wine was cation exchanged with a resin regenerated with hydrochloric acid and mixed back in growing proportions with the original wine. The exchanged portion of wine showed a strong modification in acidity, pH, and most cations but the sodium, chloride and alcohol contents were not affected. A 20% mixture of exchanged wine was enough to reach stability within OIV limits, only in wines previously submitted to a cold treatment. A 30% level of mixture originated composition changes beyond the limits accepted by OIV, and did not assure tartrate stability in wines without a previous cold treatment.