This International Standard specifies a reference method for the determination of the ash of caseins obtained by rennet precipitation and of caseinates, with the exception of ammonium caseinate. NOTE For the determination of ash (“fixed ash”) of acid caseins, of ammonium caseinates, of their mixtures with rennet casein and with caseinates, and of caseins of unknown type, see ISO 5544|IDF 89 [2].