A method of and apparatus for sorting foreign matter from a flow, the method comprising the steps of: identifying objects within a flow; for each identified object, determining reflectance intensities at at least two different wavelengths or ranges of wavelengths; and for each identified object, comparing the reflectance intensities at the at least two different wavelengths or ranges of wavelengths to a reference intensity profile, wherein the identified object is characterized as foreign matter when the reflectance intensities at the at least two different wavelengths or ranges of wavelengths fall within a predetermined region of the reference intensity profile.