Coffee Roasting

Coffee roasting transforms green coffee beans (moisture 10-12%, no flavor, starchy) into roasted coffee (moisture 1-3%, hundreds of volatile aroma compounds, soluble for extraction) through controlled application of heat (150-230+ degrees C). Key chemical transformations: Maillard reaction (browning, flavor development), caramelization (sugars), pyrolysis (cell structure degradation), CO2 off-gassing (freshness indicator). Roasters use time-temperature profiling, rate of rise (RoR) control, and Agtron color measurement.