The formation of stars is usually accompanied by the launching of protostellar outflows. Observations with the Atacama Large Millimeter/sub-millimeter Array (ALMA) will soon revolutionize our understanding of the morphologies and kinematics of these objects. In this paper, we present synthetic ALMA observations of protostellar outflows based on numerical magnetohydrodynamic collapse simulations. We find significant velocity gradients in our outflow models and a very prominent helical structure within the outflows. We speculate that the disc wind found in the ALMA Science Verification Data of HD 163296 presents a first instance of such an observation.