Roast level
also: roast degree, degree of roast
How far a coffee was roasted, from light to dark, which shapes its acidity, body, sweetness, and roast flavor.
Roast level describes how far a green coffee was roasted, from light through medium to dark. It is judged mainly by bean color and the cracks reached during roasting: lighter roasts are dropped around first crack, darker ones approach or pass second crack.
Why it matters: roast level is one of the biggest drivers of how a coffee tastes, sometimes more obvious than origin or process. Lighter roasts keep more acidity, brightness, and origin character, often with lighter body. Darker roasts trade that away for heavier body, lower perceived acidity, and roasty, bittersweet, smoky notes from longer browning. Mediums sit in between, frequently the sweetest and most balanced.
Color is a useful shorthand but not the full story, since the path of the roast (its heat and development time) matters too. Roast level also affects brewing: darker roasts are more soluble and usually want slightly cooler water (see water-temperature-by-roast). For a full walkthrough of the spectrum, see roast-levels-explained and the entries for light-roast, medium-roast, and dark-roast.