DIN 10776-1:1987-04

This standard specifies a method for the determination of pH and acid content. It is applicable to roasted coffee and decoffeinated roasted coffee. Measurement of the potential difference between a glass and a reference electrode in a definited water extract to determine the pH.*Titration of a aliquote part of the water extract with sodium hydroxide-standard solution (0,1 mol/l) to pH 6,00, 7,00 and 8,00. The acid content is expressed for pH 6,7 and 8 in mmol sodium hydroxide per kg coffee.