To provide a method and apparatus for measuring the dispersion stability of a suspension of insoluble particles before the suspension begins to generate phase separation.

In the method for measuring the dispersion stability of the suspension (a) the suspension containing insoluble particles is provided, and (b) suspension is exposed to light, having at least one wavelength, while insoluble particles are suspended uniformly in the suspension (c) the quantity of scattering light due to the suspension is measured, and (d) by analyzing this quantity of scatted light the presence of modified insoluble particles is detected, on the basis of the quantity of scattering light.