The article describes a non‐intrusive technique that is used to investigate the sedimentation/creaming of particles in a dispersion dire to gravity. The velocity of ultrasound is measured over a series of heights in the dispersion, and the data are converted to concentration profiles which are collected over a period of time. Often the method detects sedimentation/creaming at a very early stage and can therefore predict the long‐term shelf‐life of a product. The concentration profiles reveal information on the mechanisms of separation, and in certain cases give the particle size distribution and properties of the sediment/cream layer. The application of the technique to dairy products is disc