The Basic Home Coffee Roasting process
Filling the Roaster:
You fill the roaster with a measure of beans (the measure varies from roaster to roaster, its about 2.5-6 ounces by weight on the fluid beds and 10-16 ounces in the Gene/Behmor). With a fluid bed roaster, like the I-roast 2/Freshroast Plus the more coffee you roast, the hotter it gets. However, if you roast too much coffee per batch, the roast becomes uneven and the roaster can overheat. I recommend staying within the manufactures guidelines.
Set the time or pick a profile:
You then set the roaster’s duration and heat profiles (if applicable). Check out understanding your home coffee roaster for detailed tips on individual roasters.
Watch and Listen:
The coffee starts as a pale green color, except for the decafs, which are already brown. As the coffee begins to roast, the coffee changes to a straw color (tan) and you will notice a kind of wet straw smell. The roast will continue to progress with the coffee gradually darkening, progressing from a light brown to a black, the smell will change from a light roasted coffee smell to a pungent smell with visible smoke. A medium roast or city roast is brown and the beans dry. A full city roast is a dark brown with the beans showing a little oiliness. And a full city plus (+) is a dark brown that is oily. The terms Vienna, French and Italian are all dark roast terms generally progressing from dark brown to almost black. As you roast darker than full city plus, you will find that you are tasting the roast and losing the unique characteristics of the coffee itself.
Coffee can "pop" twice during roasting. The first crack or pop is when the coffee expands and breaks its husk. The roaster collects this husk or chaff. The second pop is when moisture that has collected, expands and cracks the bean. A full city+ roast is about 1 minute after this second pop. The pops are audible, like when popcorn pops, but a bit quieter. With some coffees, I prefer a lighter roast, and stop before 2nd crack.
If you see visible smoke and the smell becomes pungent, that is a sign of a medium dark roast. If you reach this point, I would suggest terminating the roast, by advancing to the cool setting. Soon you will be able to judge roast time by smell and sound. . . and if you prefer a full city or full city plus roast, you'll know how to get it.
Roaster Cool Down:
The Home-Roaster also has a built in cooling period. This allows the beans to cool enough to handle, and allows the equipment to cool and prepare for the next batch. After the built in cooling period, the coffee is done. It’s best to let it rest for at least 12-24 hours. Enjoy!