Sent out a bunch of IKAWA profiles for students in yesterday's class. I had 16 of those for a variation on the workshop done with that roaster, 8 batches that go from light to dark roasts then 2 batches with timing variations (faster and slower) for while the coffee is yellow, brown, between cracks, and beyond 2nd crack.
Here are the graphs. B-1 has a 15.71% mass loss and the ground coffee measures 53.7 on the Agtron gourmet scale. B-2 has a slightly higher 15.86% mass loss and a slightly lighter 53.9 degree of roast. Those post-roast measurements are closer than some roasters get trying to follow the same plan but these are clearly very different roasts.
Going through the roasting data for tomorrow's class and I'm really excited about the B-1 and B-2 pair. I roasted these to the same ending temperature but according to extremely different roasting plans (B-1 is a pretty extreme profile), ending up with ground degree of roast and percent mass loss measurements that are almost identical, so it's a great example to show the limits of using those numbers as a proxy for consistency. I think I need to add another slide for this pair.
Author of Typica software for coffee roasters.