An emulsion is a dispersion of one fluid in another nonmiscible fluid, stabilized by a surfactant. Such a mixture is not at thermodynamic equilibrium, and some energy is needed to create the unfavorable interface. This energy is provided by a mechanical stirring. Due to the preparation process, the surfactant is shared among the oil/water interface (droplets surface) and the continuous phase. In this paper, we estimate the emulsification rate in relation with both the dispersed phase volume fraction and the mechanical stirring. For low volume fraction, this rate is very low showing that the mechanical stirring is inadequate, whereas it becomes more efficient (but still insufficient) for higher volume fractions. Using small-angle neutron scattering under shear and rheological measurements, we follow the surfactant distribution when applying a steady flow : small shear flows help the aging whereas high shear flows improve the fragmenting and hence the emulsification.