Abstract: The invention concerns a method and device for determining the temperature stability of a water-hydrocarbon emulsion capable of phase separation by monitoring the weight variations of a gravimetric sensor part of which is immersed in said mixture. The method consists in a first step of cooling or heating the emulsion to a predetermined temperature; and a second step during which the emulsion is maintained at this temperature, the time-dependent variation curve of said weight in time enabling the determination of the solid mass collected and the separation speed into two phases by determining the slope of this curve, the stability of the emulsion being obtained by comparison with reference emulsions known to be stable.