For about the first 5 to 6 minutes is the drying process. So pretty much the coffee has 9-13% moisture retaining left in the beans. The roasting process pretty much takes that moisture and is forcing it out in the first 5 to 6 minutes. And then we start to notice a color
change after that. Green beans will turn to a more pale color, and have a white appearance. And from there we start to develop more. The sugars start to yellow and brown. Once we enter the about 75% portion of the roast, we enter what we call first crack. It’s kind of the first physical change of the coffee outside of just the color. It forces the outer skin around the coffee bean to expand and crack. So it sounds a lot like popcorn popping in the drum, and the bean increases about 20% in size. From there is where we start to develop all those sweet carmelizations, the sugars really come out. Shortly after that we reduce the heat on the roast to allow the coffee to use its own momentum from first crack to finish. And then from there this door will open once the roasting process is finished. Coffee will drop down into this tray where a fan will kick on and immediately stop the roasting process and halt everything.