Degree Dornic

The degree Dornic ( unit symbol : ° D ), named after the French agricultural engineer Pierre Dornic , is a common dimensionless unit of measurement in France and the Netherlands for determining the acidity of milk , similar to the Soxhlet-Henkel number  (° SH).

The Dornic grade is defined as the volume of 1/9 molar sodium hydroxide solution that is required to change the color of the phenolphthalein pH indicator to pink (=  basic ) in a 100 ml sample :

${\displaystyle {\text{°D}}={\frac {V_{\text{NaOH 1/9-molar}}}{\text{100 ml Milch}}}={\frac {9}{4}}\cdot {\text{°SH}}={\frac {9}{10}}\cdot {\text{°Th}}}$

Normal milk has an acidity of approx. 15 ° D.

See also

• Degree Thörner  (° Th)

Web links

• © Russ Rowlett and the University of North Carolina at Chapel Hill. In: unc.edu. Retrieved November 15, 2015 . 

Individual evidence

1. ↑ titratable acidity in: milk.polybum.com. Retrieved November 28, 2015.