Development Phase (Roasting)

The development phase is the concluding segment of a coffee roast, beginning at the moment of first crack and ending when the roaster drops the beans into the cooling tray. It is during this window that the majority of Maillard and caramelization reactions complete, generating the sugars, acids, and aromatic compounds that define the cup's final flavour profile. Expressed as a Development Time Ratio (DTR), it should typically represent 15–25% of the total roast duration: a DTR below 15% leaves the coffee underdeveloped (grassy, sharp, cereal-like), while one exceeding 30% risks a baked or flat profile with diminished aromatics.