A method for processing a high-lactose aqueous fluid (HLAF), such as permeate from ultrafiltration of whey fluid, is provided. The process includes introducing a highly concentrated high-lactose aqueous fluid into a cooling, concentrating, crystallizing apparatus in which the highly concentrated high-lactose aqueous fluid is exposed to mixing and to movement of a gaseous fluid at a temperature, moisture content and air speed effective to create a cooling, concentrating, crystallizing cascade to generate a partially crystallized high-lactose aqueous fluid and spraying the partially crystallized high-lactose aqueous fluid into an enclosed drying chamber containing hot air to form a high-solids crystalline product rich in crystalline alpha-lactose monohydrate crystals.