The use of steam preconditioners in front of cooking extruders has in recent years become quite common. In fact, from only one extruder manufacturer offering this option approximately 20 years ago, virtually all extruder manufacturers now offer this option. There are a number of advantages to using preconditioners, including the replacement of mechanical energy with thermal energy. For a "typical" cooking process, the advantages of replacing mechanical energy input with the thermal input of the preconditioner can be readily quantified. This column illustrates that quantification.