What Flavor Changes Occur in Light Roast vs. Medium Roast Coffee?

For professional coffee knowledge exchange and more coffee bean information, please follow Coffee Workshop (WeChat public account: cafe_style)

FrontStreet Coffee's Guide to Roasting: Flavor Changes in Light and Medium Roasts

Light roasting uses gentler heat, preserving the maximum floral and fruity acidic aromas from "enzymatic reactions," making it easy to detect the coffee's floral and fruit acidic fragrance. As roasting continues, moving from the end of first crack to medium roast before second crack, or even medium-dark roast just reaching second crack, most of the "enzymatic reaction" acidic aromas are broken down, replaced instead by the flavor profiles from "Sugar Browning" and "Maillard Reaction." The sugar browning reaction in medium roasting primarily refers to caramelization and the production of caramel aroma, while the Maillard reaction is more complex—it's a browning and aroma-creating reaction combining carbohydrates with amino acids, producing captivating aromas of nuts, grains, dark chocolate, and milk chocolate.

Sucrose content in green beans accounts for about 6-9% of bean weight and is the primary material for caramelization. Sucrose is thermally decomposed into low molecular weight monosaccharides—glucose and fructose—at approximately 130-170°C, releasing aroma and carbon dioxide. However, as the roasting temperature increases above 180°C, these low molecular weight monosaccharides continuously polymerize and concentrate, forming darker-colored, medium molecular weight caramel components with burnt sweet aromas. The caramelization process nears its end just over 200°C, eventually leading to complete carbonization.

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473