When thinking of coffee beans roasting and cracking at some point during the process I can’t help but think of a jack in the box toy. It’s probably because I imagine I would jump each time the first bean “cracks”. Maybe it’s a good thing I don’t do the roasting myself!
What is this cracking I am referring to?
During the roasting process, there are two distinct cracks that come from each coffee bean. Both sounds are distinct and noticeable.
The first crack is heard when the moisture inside the bean reaches a temperature point where it becomes steam. This steam causes the shell of the bean to snap off – creating a sharp crack.
The second crack occurs once the bean heats up enough to start cooking. At this point, the cell walls are breaking down and make a much softer cracking sound. It is this second crack that signals the end of the process – the oils are released and the flavor of the coffee is truly developed.