During the coffee roasting process, green beans absorb heat starting from a low temperature. The Rate of Rise (RoR)—the speed at which the temperature increases per minute—reaches its maximum value early in the roast and gradually slows down throughout the process. This is a natural physical phenomenon. Roasters adjust heat application to influence the RoR, controlling the beans' heat absorption rate in an attempt to fine-tune the flavor profile. A common pattern involves the bean temperature...

Coffee Roasting Process: A Perspective on Rubbery and Glassy States When analyzing the roasting process through the lens of material states—specifically the transition between rubbery  and glassy  states—we begin with the fundamental nature of heat absorption in green beans based on two core principles: Core Principles Phase of Maximum Efficiency:  The most efficient heat absorption occurs before 150°C . Because the bean temperature is low, the temperature gradient ($\Delta T$) between the...

How many type of processes? In the past, green coffee processing was limited to Natural and Washed methods. However, since the introduction of Honey processing, we’ve seen more and more techniques emerge, such as: Black Honey processing Anaerobic fermentation Enzyme-assisted processing, and so on. In recent years, Colombian coffee estates have been particularly aggressive in developing post-harvest fermentation methods, primarily to increase the market value of their green beans. Generally,...