If fat is not found in the original food product, it may be added to reach a certain composition. The more fat in a product, the lower the viscosity and the more difficult becomes the spray drying (powder deposits). If the fat is found in free form (unprotected by proteins) in the final product, the drying operation becomes even more difficult. Homogenization of the concentrate prior to spray drying is therefore recommended. Homogenization will increase the viscosity of a concentrate slightly.