Abstract
Grape-musts with low titratable acidity and high pH are a more and more common problem in different winemaking areas. In winemaking pH plays an important role and winemaker have a choice of different technical solutions to reduce pH. In this paper the pre-fermentative application of cation exchange resins as an alternative to the commonly used L-(+) tartaric acid addition is investigated for Pinot blanc and Chardonnay. Cation exchange resins, not only lower pH and increase titratable acidity, they also remove important amounts of cations from the must. Due to these huge differences in must composition among the two treatments, also other reactions such as tartrate formation are concerned. In the case of potassium, differences in the must were almost compensated through formation of tartrate during winemaking. Non treated control wines ended up with higher potassium but lower calcium contents. Sensory tests of the obtained wines 6 and 18 months after treatment, showed no negative impact of the cation exchange resins on wine quality compared to tartaric acid addition. Furthermore it could be demonstrated that independently from the applied technique, managing must pH helps to improve overall wine quality.