My Fagor pressure cooker manual talks about the "Natural Release Method: Foods like stocks, tomato sauces and certain cuts of meat benefit from continued cooking in a cooker after the burner has been turned off. With the natural release method, the pressure and temperature drop naturally after the unit is removed from the burner. The natural-release method can take anywhere from 10 to 20 minutes."
If the whole point of pressure cooking is speed, why wouldn't I just cook the food longer, then quickly release the pressure?
For example, in their cooking time guide:
It says cook 2-3 pounds of breasts (bone in) for 8-10 minutes, then do a natural release for 10-20 minutes.
In contrast, I've read elsewhere that a whole 3 pound chicken cut-up should cook in about 6 minutes per pound (or 18 minutes cook time).
What really seems bad about the natural release method is that if it's under-cooked, you need to get the cooker back up to pressure, cook more time, and the extra cook time will really increase the total time.