I am struggling to get a dark roast with separation between first and second crack within the Rao parameters. If you're shooting for FC+ to French, do you ramp more slowly so you can get further along in your development 25%? Or move fast so you have the momentum to get from first crack to deep second quickly? By my figgering, if I hit first crack at 9 minutes, I'm looking to drop at 12, right? With a 1.5 minute first crack, that's a lot of ground to cover with a decent separation between cracks. Perhaps a slower ramp, shooting for first at 12 min and dropping at 16 min? I use an unventilated tosta caffe, essentially a high carbon steel drum that holds a lot of heat and a coleman propane stove. I have to use charge temp and size to control my outcomes, applying high heat at the outset and slowly backing down as the beans yellow.

I know I needn't justify my taste, but I love the bitterness of a dark roast as a component of an espresso blend. Don't hate!
Thanks all.

I'm not an expert but through my experiments, rushing a dark roast has never been a successful endeavor

If this is any consolation- it's difficult, even on a 12k roaster. Particularly past a certain point in 'darkness.'

Most of my dark roasts are done by 440 to 443 on my roaster (by my definition). When I go to do a French roast my finish temp is 20° higher and I don't sweat the curve. Even if I get a good declining RoR it's probably going to be more than 25%. I get pretty close but even with no added heat the coffee flicks as it heads towards that third crack

Forgot to mention, I generally hit FC around 10 minutes for that reason of giving more dev time.

I suspect Rao's advice isn't geared towards roasts this dark. What I'd watch out for instead is that you're not blowing out bits of the beans, those little circles that pop off perfectly good beans because too much energy got into them. I think some call it chipping.

Keep trying, I believe there is value in learning how the whole system works and the attention you pay to what you're doing should give you insight! Keep notes and see what you like.

It would depend on the roaster. For example, cooking popcorn in a frying pan comes out different than in a air popcorn machine. High end drum roasters use hot air as the main method of heat transfer. Whereas roasting in a hot drum (less expensive) would use conduction. While both methods use drums, the differences in heat transfer would make them behave different.

Cheers

The question is: why?

Scott's method is designed to maximize fruit and floral"coffee" flavors . By definition, roasting dark is an exercise in "roaster" flavors chocolate and charcoal at the expense of that which a declining ROR roast is meant to achieve.

I'm not finding fault in your personal preference and I'm okay with dark roasted coffee. Some of my best friends drink dark roasted coffee.

You can do it, but I doubt it's going to change your outcome much.

Rao's suggestions work for all roast styles; I think dark in particular even if that isn't what the book explicitly discusses. I think 12min first, 16min drop is fair game; Aim for 8min yellow and it should turn out great. 16min is super easy to control and keep the ROR gently descending. You'll enter 1st at 20F/min, and allow it to descend only to 16F/min by the end for a full French roast, or enter at 16F/min, descending to 10F for Vienna.

You'll find coffees that follow the concepts in his book are much fuller, sweeter, and less prone to scorch/bake/tipped defects, and much better developed at all roast levels.

I totally agree up to this point: "I use an unventilated tosta caffe, essentially a high carbon steel drum that holds a lot of heat and a coleman propane stove."

I'd be interested to hear if there is a difference in the cup if/when Felice figures it out.

I missed that. It's basically impossible to sculpt a roast properly without airflow AND agility.

I was always under the impression that after the end of first crack, it's ok to let the RoR rise again. Is this not the case?

An increasing ROR results in baked flavors, pretty much without exception. This is because the outer surface is getting too much heat from outside and not enough moisture from within. Managing the ROR going into and coming out of the crack is instrumental to achieving even development and avoiding harsh baked or grainy underdeveloped flavors. It took some hand holding to help me figure out just how good the recommendations in Scott's book were.