Total Acidity

total acidity (TA), measure of the total acidity, both fixed acids and volatile acids, present in grape juice or wine. With alcoholic strength and residual sugar, total acidity is one of the most common wine measurements involved in any wine analysis.

It is obtained by a laboratory process called titration (which is why it is also referred to as titratable acidity, although technically they are not exactly the same, according to Boulton), in which very small additions of an alkali of known strength are made to a measured quantity of the grape juice or wine until the amount of added alkali just equals the amount of acids in the sample. The value of these total acids can be calculated and expressed as grams of any number of different acids per litre of juice or wine. By tradition, different wine regions have chosen to express total acidity variously as tartaric acid or sulfuric acid, or milliequivalents.