one way of modeling phenomena in typical physical settings is to study pdes in random environments. the subject of stochastic homogenization is concerned with identifying the asymptotic behavior of solutions to pdes with random coefficients. specifically, we are interested in the following: if the random effects are microscopic compared to the length scale at which we observe the phenomena, can we predict the behavior which takes place on average? for certain models of pdes and under suitable hypotheses on the environment, the answer is affirmative. in this talk, i will focus on the stochastic homogenization for reaction-diffusion equations with both kpp and ignition nonlinearities. in the large-scale-large-time limit, the behavior of typical solutions is governed by a simple deterministic hamilton-jacobi equation modeling front propagation. in particular, we prove the existence of deterministic asymptotic speeds of propagation for reaction-diffusion equations in random media with both compactly supported and front-like initial data. such models are relevant for predicting the evolution of a population or the spread of a fire in a heterogeneous environment. this talk is based on joint work with andrej zlatos.