In previous roasting of Sumatra beans I settled on the following roast profile:
00:00 - 04:00, 350 F
04:00 - 06:00, 400 F
06:00 - 07:00, 450 F
07:00 - 08:00, 500 F
This resulted in first crack near the 7 minute mark and second crack near the 9 minute mark. Both cracks were very pronounced.
This time I started at a slightly higher temperature.
The roast started at 375 F, increased to 425 F at four (4) minutes and then to 475 F at eight (8) minutes.
This is the first batch of roasts I completed with the new marker feature. I've since increased the width of the marker lines to make them more pronounced.
The first crack occurred a minute earlier due to the higher starting temperature. The second crack occurred a minute later due to not increasing the temperature as fast after the four (4) minute mark. The second crack was very weak so I am going to stick to the original profile.
Tried the coffee after four (4) days rest and it was not quite as flavorful as the original profile. A little ashy aftertaste. It was still good but the original profile did not have any ashy aftertaste.