The “golden period” of roasting where the color of the once-green coffee bean changes from pale yellow to bright orange. The roasters gently heat the beans and maintain a low minute-to-minute temperature increase. It is in this stage of the roast between minutes 2 and 7 – 8 and at 230-340°F that the Polysaccharides split of into Monosaccharides (simplest form of sugar and are usually colorless, water-soluble, crystalline solids) building a foundation of simple sugars.
Between 7 and 12 minutes and 240-392°F, roasters starting to dig into the foundation of sweetness that had just built, and the beans start the Maillard reaction, which is the caramelization of those simple sugars.
At the beginning of this period roasters start to apply more heat so they can stay ahead of the exothermic ( An exothermic reaction is a chemical reaction that releases energy in the form of light or heat)reactions. If the environmental temperature stays ahead of the bean temperature, they are less likely to lose the simple sugars that have developed as paralysis of the cellular structure breaks down and first crack occurs.