The Maillard reaction is a series of non-enzymatic browning reactions between amino acids and reducing sugars. In coffee roasting, these reactions generate hundreds of aromatic compounds responsible for sweetness, nuttiness, and complexity.
Maillard reactions occur over a temperature range and accelerate as moisture decreases. Roast time and temperature determine which pathways dominate. Short, hot roasts favor sharp flavors, while longer roasts enhance caramelized sweetness.
Controlling Maillard development allows roasters to shape flavor without masking origin character.