Saponification value

A small aliquot of oil is refluxed in an excess of alcoholic potassium hydroxide solution. Once saponification is complete the residual potassium hydroxide is titrated against a standard solution of hydrochloric acid using phenolphthalein indicator.

Method used BS 684, Section 2.6
Units mg KOH/g oil
Significance of result
The saponification value is used primarily as an identification aid as adulteration with unsaponifiable matter is easily seen.
Notes By dividing 56100 by the saponification value an approximate measure of the average molecular weight of the acyl chain can be found (this is known as the saponification equivalent).
Tetst Tube and Flask