A quick release is a term used often when cooking with the Instant Pot. Once the pressure is reached and the rice has cooked fully, the timer will go off.  You have two options at this point. You can either perform a Natural Pressure Release or a Quick Pressure release. A natural pressure release will slowly release the pressure from the pot, which can take about 20 minutes. The pot will not unlock until all of the pressure is gone, and, in the meantime, the food will continue to cook inside.  A Quick Pressure release means that you open the pressure valve to release all of the pressure at once. This takes about 30 seconds, after which the Instant Pot unlocks. The food then stops cooking and can be served immediately.  There are different uses for each option, but in the case of our brown rice, the Quick Release is what we want.  I also have this article on how to make Instant Pot Wild Rice.