Clay research at the site of Chokepukio in Cuzco, Peru examines the transition between open firing (indigenous bonfires) and closed (Spanish kilns) firing techniques. This investigation addresses the technological limitations of pottery pastes that were formulated for open firings as compared to the limitations built into pastes created for kiln firing. Comparing the vitrification structures present in sherds using refiring studies, petrographic analyses, and SEM, it is possible to identify the relative maturation temperature of clay recipes from potsherds. In some cases, it has been found that examples of sherds with pre-Inca designs were made using clay recipes adapted for firing in high temperature kilns. Technological information from the site will be compiled with the vessel for and design motif typology to fine tune the site sequence and identify historical period indigenous contexts in the archaeological record.