Posted by Sherman on 10/24/2010 18:15
4 min to yellow (beans should be yellow by the time they hit 300F, or you're going too fast)
4 min to first crack (first crack regularly was 400F~405F range)
2 min duration of first crack (first crack usually ended around 415~420F)
2 min more to full city + (cusp of second crack, 435~440F)
Riffing on seedlings: (all temp measurements are BT with 350g loads)
1) as fast as possible to 250F
3) 180-210 seconds to 300F
2) as fast as possible to 1C
4) 6-10 seconds/1F to end, depending on bean and final target temp. Harder beans, lighter roasts go a little slower (closer to 10s/F), darker roasts go a little faster (closer to 6s/F).
Different beans call for different end times; I just finished some Poco de Caldas from Brazil that was great with a 6s/F final ramp ending at 438F, just when 2C started rockin', and am going through a HHT that works well with a 10s/F to 428F, just before the outliers of 2C.
I don't claim that any of this was exhaustive (i.e. "did you do double-blind batch testing at 0.1F increments?!!?!" ), but it tends to work well for me. Also, these are all roasts for espresso, pulled on a lever. So yeah, there's another variable that I haven't accounted for ;)