Slow molecular beams allow for a very sensitive test of the Standard Model of particle physics. We are particularly interested in measuring the electron electric dipole moment (eEDM) in heavy diatomic polar molecules. The precision of these measurements is limited by the statistical measurement uncertainty. To minimize the latter, we build a cryogenic buffer gas source that produces slow intense beams of SrF (strontium fluoride) molecules. The molecules are further decelerated with a 4.5-meter-long Stark decelerator. After transverse laser-cooling the beam, a very sensitive eEDM measurement can be performed in the future