A method and apparatus for analyzing a bitumen-containing process stream and controlling a process. The method including directing a beam of infrared light at the bitumen-containing process stream, capturing light corresponding to the infrared light after interaction with the bitumen-containing process stream, and analyzing the captured light to obtain a spectrum. A composition estimate can be generated based on the spectrum and a calibrated model. A controller is operative to adjust a setpoint of the process in response to the composition estimate.