I recently grabbed a coffee with a former coworker of mine to catch up. Among the many things we discussed was his enthusiasm for home-roasting coffee, which intrigued me as someone who occasionally brews beer and who regularly drinks coffee. (Thanks go to Mike on the former; blame goes to Andrea for the latter.) So I figured it'd be an interesting thing to try, and given the super useful info and pretty cheap goods from Sweet Maria's, I was able to get started for little green and in little time.
The super cheap way is to use a standard popcorn air-popper (of a particular design), which Sweet Maria's sells along with some sampler beans. Roasting outside to prevent mess and smell inside, I got setup behind the house:
It's crazy simple: put a small amount of unroasted beans into the air-popper and turn it on.
I had an apprentice roaster to help me monitor the process:
After only a few minutes, the beans started moving around more easily due to the moisture having been burned off; the chaff from the beans started coming off; and we started getting our City roast (with an audible crack).
After about six minutes, I stopped the roasting to cool off the beans. Being my first go at the process, I opted for under-roasting rather than over. Here's the color comparison between the smallish batch and the original green bean.
I did this three times at approximately the same time:
This gave a pretty light bean:
Protocol is apparently to let these off-gas their CO2 for the next few days, so we'll be trying these out fairly soon.