ABSTRACTAn experimental program was carried out in order to provide insight into the effects of the design and operating conditions of spray drying on the morphological behavior of the product. Single streams of uniform‐size drops fell through a column in which air temperature profiles could be monitored and manipulated. Scanning electron microscopy and optical microscopy were used to measure shrinkage (or expansion) and to observe physical characteristics. The effects of varying the type of feed, the feed concentration, initial drop size, and air temperature history were investigated. Results are compared with previous investigations related to bulk densit