First crack

Roasting coffee is a sensory-rich journey,  filled with intense aromas, swirling motion, rising heat, and the mesmerising sounds of transformation. One of the most distinctive and exciting moments in the roasting process is what’s known as the first crack. It’s the audible cue that signals a major turning point in the roast. Think of it as the coffee bean’s version of popcorn popping, though it sounds more like a sharp snap than a pop.

This sound marks a dramatic change inside the bean: it’s cracking open, nearly doubling in size as built-up moisture forces its way out. The bean turns a light brown color and begins releasing energy rather than absorbing it. This is the moment when green coffee starts to take on the recognizable characteristics of roasted coffee.

Roasters also listen for the second crack, a softer, more subtle sound that signals the breakdown of the bean’s structure and the build-up of internal gases. By this stage, the bean becomes darker and oilier and if you’re aiming for a dark roast, this is where the magic (or danger) happens.