Acidity is one of the most important factors in wine. It affects its microbial, protein tartrate stability, malolactic fermentation, its color, flavor and aging potential of the wine. Adjusting the acidity is an important part of the winemaking process. The addition of acid to grape juice, must or wine will decrease the pH and increase TA of the wine. The low pH will make SO2 more effective against oxidation and bacterial infections, will increase the color intensity and ageing potential of the wine. The amount of acid needed to correct the acidity deficiency depends on the total acidity, the pH, and the buffer capacity of the juice, must or wine.
Addition of tartaric, malic and citric acids will affect the pH, TA and taste of the wine differently.
*1.0 g/L addition of Tartaric acid will increase the TA by about 1.0 g/L and will decrease the pH by 0.1 pH units.
*1.0 g/L addition of Malic acid will increase the TA by about 1.12 g/L and will decrease the pH by 0.08 pH units.
*1.0 g/L addition of Citric acid will increase the TA by about 1.17 g/L and will decrease the pH by 0.08 pH units.
Adding acid can result some precipitation of potassium tartrate (KHT) which will affect both pH and TA.