What role does a colloid mill play in jam production if I already use a jacketed kettle for cooking the fruit?

In jam production, the kettle handles cooking and pectin setting, while the colloid mill is used afterward or in a recirculation loop to break down fruit pieces, seeds and fiber into a fine, even texture and to disperse pectin and sugar uniformly. This reduces graininess, improves spreadability and gives a glossier finish, and the narrow rotor-stator gap can be tuned to leave small fruit chunks if a chunkier jam style is desired.