Abstract: The present invention relates to novel methods for detection of the presence or absence of particulate matter in an opaque fluid, novel methods for inspection of an opaque fluid for the presence or absence of particulate matter therein, and use of such methods in the manufacture of an opaque fluid. Methods comprise clarifying the fluid to enable detection of the presence or absence of particulate matter therein or to enable inspection of the opaque fluid for the presence or absence of particulate matter therein.