Asphaltene precipitation is caused by a number of factors including changes in pressure, temperature, and composition. This service is uses an integrated analytical measurement system with an optical probe for the detection of asphaltene precipitation from a toluene solution of the sample. Test specimens are dissolved in different quantities of toluene. The specimen/toluene solutions are automatically and simultaneously titrated with n-heptane to cause precipitation of the asphaltenes. The optical probe monitors the formation of flocculated asphaltenes during the titration. Flocculated asphaltenes will alter the detected light intensity. Start of flocculation is interpreted when the optical probe detects a significant and sustained decrease in rate-of-change of the light intensity.