The present disclosure includes a method of controlling a centrifuge for the centrifugal production of a milk product. The steps include taking a milk sample at an outlet of the centrifuge from a liquid phase, adding a substance to the milk sample that increases light transmittance of the milk sample, determining the light transmittance of the milk sample by transilluminating the milk sample using a light source and measuring light intensity via a photo cell, determining the fat content from a measurement of the light transmittance, and controlling the centrifuge as a function of the determination of the fat content. The present disclosure also includes a system for controlling the centrifuge.