Recrystallisation (RX) occurs when strain-free grains nucleate within a strained microstructure. This phenomena occurs dynamically either at high strain rates during processing or at lower strain rates during subsequent heat treatment. Ni-based superalloy single crystals are vulnerable to RX during post-cast solution heat treatments. Plastic strain manifests during cooling as a consequence of the differing thermal contraction between the metal casting and the ceramic mould. Previous studies have identified the critical temperature region for this creep deformation after casting to be between 1300°C - 1150°C. However, the current isothermal straining experimental studies in this area are limited and not representative of the industrial scenario. In this study, electrothermal mechanical testing (ETMT) has been used to measure the plastic strain evolution and the recovery during cooling and subsequent heat treatment of CMSX-4. Post-mortem diffraction analysis of the specimens reveal the sub-grain structure that precedes RX and the tendency for these structures to develop around surface features. Recovery kinetics are derived from the variation of recovery rate in as-cast specimens, giving insight into the influence of microsegregation on the thermal-mechanical response.