Samples of a long‐chain branched polyethylene were subjected to shear modification in a mixing extruder under various controlled shear conditions. The melt elasticity (time‐dependent recoverable strain) of the shear modified samples was found to decrease as the extrusion temperature was decreased or the rate of shear was increased, thereby demonstrating that the amount of shear modification can be controlled by these processing factors. The shear modification was found to be a reversible process. Reheating of the modified material resulted in the melt elasticity increasing back to the large recoverable strain exhibited by the unmodified material.