Roasting
Second Crack
A second, quieter popping phase during roasting occurring around 224-230C (435-446F) when the bean's cellulose matrix begins to fracture. Second crack signals the transition from medium-dark to dark roast.
En Profundidad
Second crack sounds sharper and more rapid than first crack, like rice cereal crackling. Oils begin migrating to the bean surface, giving the coffee a shiny appearance. Roasting into or beyond second crack progressively diminishes origin characteristics in favor of carbon, bitter-sweet, and smoky flavors. Most specialty roasters avoid second crack to preserve acidity and complexity, while traditional espresso and dark roast profiles may develop slightly into it.