Recent investigations of iron smelting in Angkorian Cambodia have focused on object-based analysis to reveal patterns of diachronic exchange between the ninth to the fifteenth centuries. While this work demonstrated shifts in the intensification and nature of iron production during Angkor’s peak in the twelfth to thirteenth centuries, less attention has been given to identifying the smelting recipes (techniques, resources) employed by producers through space and time around Phnom Dek and Preah Khan of Kompong Svay. By compiling a vast database comprising in-field pXRF slag compositional data, chronological data, and archaeological survey evidence from 156 slag concentrations it is possible to undertake a holistic metallurgical analysis capable of recognizing technical choices and even sporadic tests. Our results show important shifts in resource selection and skill that relate to political fluctuations of the Angkorian state. This new, integrative approach is offered as a model for describing a posteriori production behaviors that took place in Cambodia over a period of 1,400 years.