Plasticity in a fat may be defined as the ability to retain its shape under slight pressure, but to yield to increased pressure, such as that encountered during rolling, mixing or spreading (McWilliams, 1979). A plastic solid owes its pecular properties to the tendency of its solid particles to form jams or arches which support the material against shearing stresses. In rheological terms, therefore, plastic fats possess a yield stress. There are additional factors that determine the range within which a material will be plastic. The shape, average size and size distribution of the fat crystals play an important part in this. Equally important is the percentage of solids in a fat and the characteristic continuous variation that occurs with change in temperature. Plastic fats are processed and produced in a stable crystalline form using scraped surface heat exchangers and pin workers (Rajah, 1992). The effect of temperature upon the viscosity of the liquid phase is understood to account for as much as 30-50% of the total consistency variation (Soltoft, 1947).