It doesn’t take long for green coffee beans to turn pale in the beginning phase of roasting. They then turn a shade of yellow with an aroma somewhere between grass and hay.
The sugars and amino acids begin to caramelize inside the beans as the beans reach around 295 degrees Fahrenheit. This causes the beans to start turning brown and emit a sweeter smell.
When you hear the first crack, you know it’s getting real. Your coffee beans are breaking down, and the oils are anxious to leave them. At this point, the beans have reached the light city roast.
The development phase begins after the first crack. The beans get a bit darker and start to expand while the oils continue their exit process, still not fully exposed. Flavor morphs in a matter of seconds as the beans continue to roast. The longer you roast your beans after the first crack, the more types medium roasts they morph through.
Shortly after the second crack come the medium-dark roasts. The oils finally make it out of the beans, and the roast flavor overpowers the flavor of the original green coffee beans.
At this point, all the sugars start to burn, and carbon begins to form. It’s best to stop before you catch something on fire….
Roasting Tip: If possible, roast your coffee beans outdoors. Roasting coffee beans inside has been known to lead to a smoke-filled kitchen and the sound of obnoxious smoke detectors.