Welcome to the Roasting Science course. We created these lessons for professional coffee roasters who want to learn more about what’s happening during the roasting process — right down to the molecular level. We explain the science of roasting, including the physics of heat transfer into the bean and the series of chemical reactions that create many of the flavours we associate with roasted coffee. We explore the engineering challenges faced by roasting-machine manufacturers and the different approaches they have taken to solve them. Finally, we discuss how you can use this knowledge to fine-tune your own roasting style.