What does 1st crack look like?
It’s hard to see the actual An audible popping sound heard during roasting. In coffee, one refers to "first crack" and "second crack," which come from two different classes of chemical reactions.: An audible popping sound heard during roasting. In coffee, happen when you are properly roasting coffee and your beans are rapidly moving around inside of your roaster.
We thought it would be fun to toss a few test dummies into a toaster oven, turn it up to about 500° and watch them actually crack.
Please note: this is not a roasting tutorial. Although you can see the beans getting darker and cracking, they are pretty uneven and pretty scorched a few minutes in.
Also see: Sweet Maria’s Macro Coffee Images