267. Studies on the chemistry of Cheddar cheesemaking VII. The measurement of the acidity of cheese and the relation of acidity to grading score

Abstract

The pH of cheese at 14 days old appears to be the most useful means of measuring the extent of acid development in the cheese, and shows a very fair agreement with the observations of graders on mature cheese. Cheese with a pH value close to 4°90 at 14 days gained the highest average score at maturity.Measurements of titratable acidity either on the aqueous extract of the cheese or directly on a paste of the cheese, readily distinguish cheese which are insufficiently acid, but do not clearly distinguish over-acid cheese or cheese of low pH value: The direct method of acidity titration has the disadvantage that the results are affected to such an extent by the colour of the cheese as to make impossible the comparison of results on cheese of different colour intensities.pH or titratable acidity values for mature cheese are less useful indicators of the quality of the mature cheese than the values at 14 days.