Glass Transition
Glass Transition is a physical transformation in which a material shifts from a brittle, glass-like state to a more flexible, rubber-like state when exposed to heat.
During coffee roasting, this process occurs as the temperature rises. When coffee beans are heated, the polysaccharides in their structure undergo changes, making the beans more pliable and elastic. This allows the beans to expand rapidly, creating the characteristic porous structure of roasted coffee.