Determination of titratable acidity in milk according to DIN 10316 and in yoghurt according to ISO/TS 11869 and IDF/RM 150

The titratable acidity gives an indication of the freshness of milk and yoghurt and other fermented milk products. The determined titratable acidity in milk is mainly given through the absorption of hydroxyl ions via milk proteins and milk salts. The acidity increases with bacterial acidification and with enzymatic lipolysis.

The titratable acidity corresponds to the amount of milliliters c(NaOH) = 0.1 mol/L consumed to reach a pH value of 8.30 for 10 g sample.