Roasts

 Everyday alchemy, coffee roasting coaxes golden flavor from a bland bean. Unroasted beans boast all of coffee’s acids, protein, and caffeine—but none of its taste. It takes heat to spark the chemical reactions that turn carbohydrates and fats into aromatic oils, burn off moisture and carbon dioxide, and alternately break down and build up acids, unlocking the characteristic coffee flavor. 

 Aliases: Cinnamon roast, half city, New England
Roaster Watch: After about seven minutes the beans “pop” and double in size, and light roasting is achieved. American mass-market roasters typically stop here.
Surface: Dry
Flavor: Light-bodied and somewhat sour, grassy, and snappy 

 Aliases: Full city, American, regular, breakfast, brown
Roaster Watch: At nine to eleven minutes the beans reach this roast, which U.S. specialty sellers tend to prefer.
Surface: Dry
Flavor: A bit sweeter than light roast; full body balanced by acid snap, aroma, and complexity 

 Aliases: High, Viennese, French, Continental
Roaster Watch: After 12 to 13 minutes the beans begin hissing and popping again, and oils rise to the surface. Roasters from the U.S. Northwest generally remove the beans at this point.
Surface: Slightly shiny
Flavor: Somewhat spicy; complexity is traded for rich chocolaty body, aroma is exchanged for sweetness 

 Aliases: Italian, espresso
Roaster Watch: After 14 minutes or so the beans grow quiet and begin to smoke. Having caramelized, the bean sugars begin to carbonize.
Surface: Very oily
Flavor: Smokey; tastes primarily of roasting, not of the inherent flavor of the bean