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Acid Titration Calculator


The Acid Titration Calculator determines the titratable acidity (TA) of a wine sample given the volume of the sample and the volume of sodium hydroxide (NaOH) added during a titration test.

Input Field Definitions

Wine Sample Volume – The volume of the wine sample being titrated.

Volume of NaOH Added – The volume of NaOH solution required to reach the titration endpoint.

NaOH Normality – The normality (moles/liter) of the NaOH solution used to titrate the wine sample.

Output Field Definitions

Titratable Acidity (TA) – The calculated titratable acidity of the wine sample.

Calculation Details

Acid titration makes use of the neutralization reaction between NaOH and the acids present in wine. In this reaction, the OH ions contributed by the NaOH and the H+ ions contributed by the wine acids combine to form water, H2O. The reaction is complete when all of the H+ ions have been neutralized by OH ions.  Since each OH ion neutralizes one H+ ion, we can write a balance between the H+ and OH ions as:

ia(ma/mwa) = vnNn


ia = number of H+ ions donated by each molecule of acid

mwa = molecular weight of acid, grams/mole

ma = mass of acid, grams

vn = volume of NaOH added, liters

Nn = normality of NaOH solution, moles/liter

The mass of the acid in solution is simply the acidity multiplied by the volume or:

ma = a·vw


a = acidity, grams/liter

vw = volume of wine sample, liters

Combining equations (3-1) and (3-2) and solving for acidity we get:

a = (mwa/ia)vnNn / vw

By titrating for acidity, all we’ve really determined is the number of available H+ ions in the solution and not the types of acid present.  For this reason we must choose an acid as a reference in order to express the acidity as a concentration. Tartaric acid is frequently used as a reference, and is the default acid reference in FermCalc. For tartaric acid, mwa is 150.09, and ia is equal to 2, so equation (3-3) becomes:

a = 75.045·vnNn / vw

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