Quantifying the light response of detector materials to nuclear recoils is important for almost all dark matter and neutrino experiments. While theoretical models exist, they offer differing features at the energy region of interest to CEvNS and dark matter searches. I describe our measurement campaign to characterize the common liquid scintillator EJ-301 at the Triangle Universities Nuclear Laboratory's Tandem Van de Graff accelerator and its support for the modified Birks' model.