Dark roast

Roast profile beyond second crack (225-240°C). Very dark brown to black colour, visible surface oils. Organic acids and origin aromas are largely destroyed; dominated by burnt caramel, smoke, tar aromas, intense bitterness. Traditional Italian espresso and instant coffee standard.

Background & Context

Dark roast refers to coffee roasted beyond the second crack (approximately 225-230°C), typically reaching Agtron scores below 35. The beans are chocolate-brown to near-black, shiny with oils that have migrated to the surface. Dark roasting fundamentally transforms the chemistry of the bean: most origin-specific aromatic compounds, the floral esters and organic acids that define Ethiopian or Colombian terroir, are destroyed or masked. What dominates instead are roast-derived flavours: melanoidins (chocolate, caramel), phenylindanes (bitter, woody), and sulfur compounds (espresso character). This is why dark roasted coffees from vastly different origins taste similar, roast flavour has overwritten origin flavour. Dark roasts have lower perceived acidity (most organic acids have degraded) and higher body (higher melanoidin content). Counter to popular belief, dark roasts are not significantly stronger in caffeine, caffeine is heat-stable and degrades only marginally even at dark roast temperatures. The 'strong = dark' misconception comes from flavour intensity, not caffeine content. Dark roasting also allows low-quality, defect-prone green coffee to be made commercially acceptable by masking off-flavours, historically, the dominant motivation for dark roasting in commercial coffee.

Practical Use

If you prefer a dark roast: look for roasters who use high-quality green coffee even for dark profiles, the baseline quality still shows in the cup even through heavy roasting. Avoid dark roasts stored for more than 2 weeks after roast date: the surface oils go rancid rapidly, producing a stale, flat cup. For espresso with dark roast: reduce extraction temperature to 88-90°C (lower temperature extracts fewer bitter fractions) and shorten the shot to 22-25 seconds.

Related Terms

Related terms: Light roastthe specialty alternative. Agtron scaledark roast = Agtron below 35. Maillard reactionproduces the melanoidins dominant in dark roast. Second crackthe roast event that defines dark roast onset.