During some time off from work this winter, I had the opportunity to learn about micro-roasting coffee from the owners of my favourite coffee micro-roaster on the Sunshine Coast, Sweet Start. They were kind enough to walk me through roasting several pounds of Ethiopian beans on their Kaldi Fortis Roaster, with a particular emphasis on the parameters required to roast Full City+ (my favourite). They had started roasting with the Whirly-Pop bbq method and worked their way up to this beautiful machine.
In addition to this experience, Kelly gifted me a Whirly Pop set up for my birthday (as well as some green beans), so I could try it myself. Today I gave it a shot and learned a number of lessons that I hope to apply with my next attempt.
I started by bringing the Whirly Pop up to 250 degrees Celsius on my BBQ propane side burner. I added 8 oz of green beans and it dropped to 164 degrees celsius before starting to rise again. I forget the temp at first crack, but I think second crack started around 190 degrees celsius. I removed the beans to cool and remove chaff at about 210 degrees celsius, which occurred at 6 minutes and 15 seconds.
A number of the stages seemed to occur too quickly at the given temp and I resulted in quite dark and oily beans. On reflection I think there are several errors I probably made, including a) starting too quickly once the thermometer reached 250 degrees celsius (might have still been heating to a higher temp), b) burner may have been turned up too high (was about midway), c) I may have not rotated the Whirly Pop quick enough leading to too much contact time.
Nonetheless, this was a lot of fun and I’m glad I have enough green beans to be able to experiment with the parameters some more. The Whirly Pop method is definitely more error-prone and finicky than the Kaldi Fortis method, but I did learn a lot about the sounds and smells of the different stages.