How the type of protein influences particle morphology remains a hot topic of debate. In this study we focused on the drying behavior of two major milk protein types; that is, whey protein and native micellar caseins. To improve understanding of the role of each protein in the particle-forming mechanisms, seven mixtures containing different whey proteins to caseins ratios were investigated. A monodisperse spray dryer (MDSD) was used to produce uniform particles by drying monodispersed droplets in a hot, dry air flow. Single particles were also obtained from the same material using single droplet drying in a pendant configuration. Powders were characterized according to their physical characteristics and their rehydration properties. It was demonstrated that particle morphology was mainly governed by the type of protein matrix, almost regardless of the drying kinetics, which differed considerably between MDSD and single droplet drying. Controlling product formulation thus represents a potential means by which to tune particle morphology and therefore the functional properties of powder.