The roast level of a coffee determines how much of the bean’s natural flavor versus the flavor of the roasting process itself ends up in your cup. Lighter roasts highlight the coffee. Darker roasts mask it under roast-derived flavors.
Light roast
Light roasts (sometimes called Cinnamon, City, or Light City) stop just after the first crack, when the beans first audibly pop during roasting. The beans are light brown, dry on the surface, and dense.
Flavor: bright, acidic, fruit-forward. Light roasts let the bean’s variety and origin character come through clearly. A light-roasted Ethiopian washed will taste of jasmine and citrus. Often higher in caffeine per bean than darker roasts.
Medium roast
Medium roasts (City, Full City) go a bit further, into or just past the second crack zone. The beans are medium brown, slightly oily on the surface in some cases, with more developed body.
Flavor: balanced. Less of the brightness of light roasts, more sweetness and roundness. Origin character is still recognizable but mellower. This is the sweet spot for many drinkers and the most common roast level for grocery specialty coffee.
Dark roast
Dark roasts (Vienna, French, Italian) push past the second crack and develop visible oils on the bean surface. The beans are dark brown to almost black.
Flavor: bold, smoky, sometimes bitter. The origin character largely disappears under the roast flavors of caramelization, burned sugar, and char. Dark roasts have less perceptible acidity and a heavier body. Per gram, slightly less caffeine than light roasts (the longer roast burns some off).
Which roast for which method
Light roasts shine in pour-over and other manual methods that highlight clarity. Medium roasts are versatile across all methods. Dark roasts are popular in espresso (for traditional Italian-style espresso) and in milk drinks, where the bold flavor cuts through the milk.