Researchers from across the Department of Energy (DOE) complex performed experiments to assess the impact of manufacturing changes on the use of IONSIV(R) IE-911, the engineered form of crystalline silicotitanate (CST), for the removal of cesium from Savannah River Site (SRS) high-level waste. Prompted by previously supplied data, UOP changed the manufacturing process to minimize the chemical instability of the inorganic sorbent that manifests itself as niobium and silicon leaching. This report includes results of the extensive examination of newly prepared laboratory-scale and preproduction samples of caustic-washed CST as compared to similar performance data for commercially available and baseline samples.Testing indicates that the revised manufacturing process removed most of the niobium (Nb) that previously readily leached from the sorbent under test conditions. The revised manufacturing also reduced the amount of easily leached silicon (Si), but a significant fraction of this material remains. Microscopic analysis indicates the presence of amorphous Si. Cesium capacity (mg Cs/g CST) or distribution coefficient (K-d) of the preproduction sample compares favorably to the baseline sample and exceeds that observed for the laboratory-scale sample made using the revised manufacturing process. Column breakthrough experiment indicates that the manufacturing change did not affect the mass-transfer zone length. Lastly, pore analysis, particle size, thermal behavior, and packing density measurements indicate that the manufacturing process change does not affect these bulk proper-ties for the engineered material.