An experiment was designed to evaluate the use of spray dryers to transform soymilk into flour. Soymilk slurries were spray dried at various combinations of inlet air temperature (255, 265 and 275°C), feed rate (0.38 and 0.57 Lpm), and rotary atomizer speed (19,300 and 26,800 rpm). Several dryer parameters and product properties were monitored and evaluated. Weather data was included;The average powder pH was 6.64 (standard deviation 0.10) which is very close to the 6.4 to 6.6 range reported in literature. Effect of process parameters on storability were studied over a one year period. Product insolubility showed dependence upon outlet temperature and pumping time, but erratic trends over time appeared unpredictable. Lightness data was a function of storage time and atomizer speed and could be predicted to within ±1.0% error;A psychrometric analysis of the spray dryer, based on collected data, estimated the ideal state of the air at the outlet of the drying chamber assuming an adiabatic saturation process. Equations to predict outlet (R2=0.99) and product (R2=0.80) temperatures as well as process efficiencies and product yields were developed from collected data;Spray dried soymilk samples with added dispersion agents (i.e. Cab-o-Sil°ler or Zeofree 80°ler) to increase flowability were sieved using ultrasonic and Ro-Tap°ler methods. Nine algorithms were used to calculate mean diameter from experimentally collected data. These values were compared with Sauter and volume mean diameter estimates obtained from six empirical relations reported in literature;Models for spray dryer reported in literature were surveyed and common model assumptions summarized. Models found were classified into static and dynamic based on their inclusion of time as one of the independent variables of the model. Static models focus on the steady state or equilibrium response of the system and provide in-depth analysis of the system's behavior. Dynamic models are used for control and focus on the maintenance of a desired outlet temperature or final moisture content of the dried powder.