  Consider a colloidal suspension of rigid particles in a steady Stokes flow.
In a celebrated work, Einstein argued that in the regime of dilute particles
the system behaves at leading order like a Stokes fluid with some explicit
effective viscosity. In the present contribution, we rigorously define a notion
of effective viscosity, regardless of the dilute regime assumption. More
precisely, we establish a homogenization result when particles are distributed
according to a given stationary and ergodic random point process. The main
novelty is the introduction and analysis of suitable corrector equations.
