Mix formulation and processing technologies are foundational steps in the successful manufacture of frozen desserts. The functional requirements of frozen desserts are significant and complex including such features as temperature-dependent malleability, air entrainment, shelf life, the generation of fat structure, desirable melt qualities, flavor character, and so forth. These functionalities are significantly affected by the foundational mix base and the processing technologies deployed for its manufacture. This chapter provides a broad overview of key unit operations significant to mix processing such as blending, pasteurization, and aging. Also included are details for the assessment of frozen dessert mixes for physical and sensory parameters.