Spray drying is a widely known method in drying process used in an industry such as food and biotechnology. The production of milk powder, citric acid and antibiotics is an example. Drying process is always placed at the final stage of downstream processing. With an action of the spray dryer, moisture of a purified product will be forced to leave at high evaporation rate causing the products dry and ready for commercial use. In an early stage, the objective of this research was to find an optimum condition for making organic acid powder using Buchi mini spray dryer type B-191. Practically, soybean milk was used as a test sample with a condition provided by the manufacturer. However, the milk powder did not show any satisfied results. As a consequence, it came to the new aim, it is an investigation on the factors that could have an influence on the performance of drying process. The investigated factors were %aspirator, inlet temperature, and feeding rate. These factors were set as constant values, which atomize flow rate of 600 L/hr was also included. Temperature profiles along the length of drying chamber at various conditions were studied using a thermocouple inserted into the chamber. The results revealed that as inlet temperature and %aspirator were increase, outlet temperature was also found to be increased. The results also showed that at any inlet temperatures, both high and low %aspirator could evaporate sprayed water at the same rate. Moreover, heat profiles in the drying chamber, between 5 cm and 40 cm level below nozzle, revealed that the various %aspirator applied did not make any changes on the temperature difference of these two levels, at any inlet temperatures applied. The knowledge obtained from this study will be used as a guide for research in the future upon an optimal condition for spray drying process of any particular products.