It became necessary during studies of pH control of butter made from cream with adjusted acidity, to study methods for determining the pH of cream and butter. serum. The acidity of the cream can be adjusted satisfactorily after the relationships between cream acidity and butter serum pH have been established. The final check of the precision with which the acid reduction of the cream is carried out, however, must be effected by a pH determination of the butter serum. For this reason methods for determining pH in cream and butter serum were studied.

The two objectives in this project were: 1. To study pH determination methods with the idea of finding or developing methods that would be suitable for use in the butter factory and 2. to determine the factors which might cause lack of agreement among different factories or laboratories.