What is a dark roast?

A dark roast enters second crack or goes beyond it, bean temp between 225 and 245 °C, Agtron 35-60, with oils clearly visible on the bean surface. Sub-grades include Full City+, French (late 2C), and Italian (past 2C). The cup veers toward dark chocolate, smoke and liquorice, with pronounced bitterness, thick body and very low acidity. It is the signature of Neapolitan espresso and many industrial blends.

Past first crack, a dark-roast profile keeps pyrolysing the bean structure. Between 219 and 224 °C sits Full City+, still manageable for specialty work. From 225 °C on, second crack opens up: a drier, more metallic snap, less intense than the first, caused by cell walls hardened by partial carbonisation finally fracturing. Oils migrate to the surface and beans look glossy. At 230-235 °C: French Roast. At 240-245 °C: Italian / Neapolitan Roast. Beyond 250 °C you are simply burning — the cup becomes acrid and one-dimensional.

Chemistry-wise, pyrolysis now destroys more than it builds. Sugars that did not caramelise char into bitter derivatives (heavy furfurals, 2-furanmethanethiol at high concentration). Origin acidity drops 70 to 90 %. Caffeine stays nearly stable (it sublimes above 178 °C but total roast loss is under 10 %). Body thickens as soluble lipids migrate to the surface and load the cup. Lesser-known fact: dark roasts lose 20 to 22 % of dry mass and up to 18 % of volume, versus only 13-15 % for a light roast — which is why 1 kg of dark beans takes noticeably more scoops.

Italian tradition (Naples, Turin) shaped this degree from the 19th century onwards, first to mask green-Robusta defects in cheap blends, then by cultural taste — the Italian love of bold espresso with tiger crema and a chocolate-hazelnut finish. Many European supermarkets still sell beans and ground coffees in dark roast, often to smooth out the quality of average commercial green coffee. In Belgium, the daily family tradition of filter coffee leans toward medium-dark, softer than strict Italian but fuller than a specialty medium — a logical partner for a speculoos, a cuberdon or a slice of cramique.

Dark roast at a glance