Homogenizer for reducing the size of particles in fluids

An exemplary homogenizer includes a valve plate stack having a shim sandwiched by a pair of valve plates, the stack being concentrically aligned by a center stud. Each of the valve plates includes a middle annulus radially situated between an outer rim and an inner raised hub. Each middle annulus includes annulus apertures that help increase flow rate. When the homogenizer is in a working position, the valve plate stack is compressed, and fluid entering through an inlet is homogenized as it passes through a gap between outer rims of adjacent valve plates. The minimum gap between the valve plates is set by the thickness of the shim. In a cleaned-in-process cleaning position, pressure is relieved from the stack, and a spring between adjacent valve plates separates adjacent valve plates. Enhanced drainage, and springs that are substantially sealed from fluids by spring retainers and O-rings, help promote sanitation.