Green coffee beans smell like grass and hay. Everything you associate with the aroma of coffee — that toasty, chocolatey, roasted-nut smell — is created inside the roasting drum.
What happens during roasting
Beans are tumbled at temperatures between 190°C and 240°C for 8–16 minutes. Two audible “cracks” punctuate the process:
- First crack — the bean’s moisture turns to steam and escapes with a popping sound (around 196°C). This is the earliest point at which coffee is drinkable.
- Second crack — the cellulose in the bean begins to break down (around 224°C). Beans now sound like crackling wood.
Light roast
Stopped just after first crack. Cinnamon-brown, dry, with high acidity and origin flavours (fruit, florals, tea-like notes). Best brewed as filter or pour-over.
Medium roast
Between first and second crack. Balanced sweetness, caramel and chocolate notes, moderate acidity. The all-rounder — works for filter, moka pot and espresso.
Dark roast
Taken past second crack. Oily surface, low acidity, big bittersweet body with cocoa, molasses and smoky notes. Traditional espresso and Southern-Indian decoctions lean darker.
Which roast should you buy?
If you drink your coffee black, start medium. If you prefer coffee with milk, medium-dark or dark will cut through beautifully. And if you love the fruity, tea-like side of coffee, hunt for a light roast.
