How Coffee Roasting Actually Works: First Crack to Second Crack

Roasting is just controlled browning — but the seconds between first crack and second crack decide whether a coffee tastes sweet or burnt.

Roasting Fundamentals

• Green beans are ~11% moisture; roasting triggers the Maillard reaction and caramelization
• First crack (~196°C/385°F): beans expand, release steam — light roast territory
• Development time after first crack determines sweetness, body, complexity
• Second crack (~224°C/435°F): oils migrate to surface — dark roast, roast flavors dominate
• Light roasts preserve origin character; dark roasts taste more like ‘roast’
• At Gillespie, we roast to highlight origin — fearlessly, not recklessly

In this episode

0:00 Drying phase and the Maillard reaction
1:03 Why browning brings out sweetness
2:09 First crack, second crack, and dark-roast oils
5:26 Drum vs. fluid-bed roasters

Watch the series: https://www.youtube.com/playlist?list=PLX4SK1C49ZWA
(This episode goes live in the playlist on its release date.)
Free guided tasting sheet: https://gillespie.coffee/pages/guided-tasting-sheet
Coffees: https://gillespie.coffee — viewers get 10% with FEARLESS10

Coffee by Gillespie · Fearlessly Roasted