I’ve been roasting coffee off and on for a while now with my popcorn popper. So far the results have been inconsistent, but the good batches have inspired me to keep trying. I plan on taking a systematic approach to coffee roasting to better understand what makes for a good batch on an air popper.

I’m using a Poppery II air-pop popcorn popper. It was a five dollar purchase at a thrift store, which was a bargain, especially compared to a real coffee roaster. If you want to try it out, get the kind of air popper with spiral air vents so you can get a vortex of hot air that spins the beans around. Some poppers just shoot the hot air straight up and this doesn’t work as well.

I purchased some green Brazilian beans and some Sumatran beans from Mr Green Beans in Portland. While roasting I’m keeping track of several parameters, including 1)  the type of bean, 2) the amount of beans per batch, 3) the duration of time until first crack, 4) the duration of roasting after first crack, and finally  5) the amount of time the beans rest between roasting and brewing.

Currently I am roasting 45g of beans per batch. I typically use 22g of beans per cup of coffee, so this is enough for two cups at a time, and the amount fits nicely in my little canisters. The Brazilian beans are smaller than the Sumatran ones, and they give off much more chaff while roasting. Since they’re smaller, they take less time to get to first crack, about 3:00, while the Sumatran ones take an extra 30 seconds. I’m not sure yet how long I should roast after first crack to get a good flavor.

I record all of the settings on the little storage canisters with a grease pencil. After brewing the coffee I rate the batch 1-5 and note any of its special qualities. It takes about 45 minutes to roast all eight canisters worth of coffee. I hope that I can speed things up once I have a better understanding of how to best roast the beans.

I’ll follow up in future posts on what roasts well in the air popper.