This International Standard specifies the reference method for the determination of fat content of whey cheese.
NOTE If the whey cheese does not dissolve completely in the ammonia or if it contains free fatty acids in significant quantities (only in exceptional cases and then noticeable by a distinct smell), the result of the determination will be too low. With such products recourse should be made to a method utilizing the Weibull-Berntrop principle (see ISO 8262-3).