Abstract: An apparatus, system and method of controlling heated air drying of product. Exhaust temperature is measured during drying and compared to a target or ideal exhaust temperature function or reference. The exhaust temperature function or reference is correlated to a target or ideal drying rate for the product. Drying factors are adjusted to compensate for variance between measured exhaust temperature and the target or ideal exhaust temperature function to influence actual exhaust temperature to follow the target or ideal exhaust temperature function during drying. Drying factors such as inlet air temperature and drying pressure can be controlled manually or automatically by the comparison to promote efficient and controlled drying.