So to set the stage for this more controlled experiment, here’s my experience with a slow-start, fast-finish approach that yield a properly developed, clean, sweet, fruited cup.





So I went ahead and roasted the last of my Tambaya AA attempting to match your profile. I charged at 400 F MET, decent amount of heat through dry, pushed quickly through ramp - though not quite enough to match your profile, and finished quickly (though a couple degrees hotter than intended).







(12.3% weight loss - super light)



And the taste - evaluated as a 1:18, 203 F Wave 155, 24 hours post-roast:



I get stewed tomato and orange from the aroma - nice and tropical. In the mouth, it’s lovely, super delicate, clean, sweet, and full of cherry, tangerine, and pineapple, with no bitterness or astringency. It’s not underdeveloped. The sugars are more delicate and fruited and hit closer to the front of my palate. They’re less syrupy and caramelized. I don’t consider this profile better or worse. I suspect that for simpler coffees, a fs-sf profile might bring out more interesting caramelized sugar notes, but for a really top notch, complex, powerful coffee like this, the slow-start, fast-finish approach works.



I’m also wondering how much the gentle charge affects the roast. When I last tried a ss-ff approach, I charged hotter and couldn’t give the roast much heat at first. With a cool drop, it was easier to finesse the roast closer to a straight-line. And I suspect there might be some issue with reactions stalling out due to insufficient heat application with an overly hot charge for a slow-start roast - but that’s pure speculation.

So, naturally, I wanted to do something more controlled. So I did two roasts of Sweet Maria’s Zonegediyo Yirgacheffe, a slow-fast and a fast-slow.

[slow-fast]

[fast-slow]

(imgur link in case these aren’t sufficiently high-res: http://imgur.com/a/5sxTw )

The above follow’s [creative nickname]’s suggestions on h-b, the second how I interpret Rao’s guidelines. In any case, the differences in the cup are apparent. The slow-fast approach yields cleaner, fruity sugars, even powdered sugar character, while the slower development phase allows a bit of caramelization, producing a candied sweetness with a much longer finish and a more syrupy rather than ultra-delicate, tea-like mouthfeel. Of course, with a super-light finish on a washed Ethiopian coffee, neither is exactly heavy-bodied. So in my opinion, these approaches are merely different. But I would add that the vast majority of coffee drinkers would prefer the slow finish.

And to verify that, I brought in these coffees to Sightglass and had my coworkers taste them. I was actually pretty surprised how one-sided preferences were. Every one of more than half a dozen baristas - many of whom who’ve been in coffee for 5+ years, who like delicate light roasts - preferred the slow-finish approach. Now this is not to say that a slow-finish is correct, but at least for most well-calibrated, American, third-wave palates, this approach seems to produce preferable results. Now of course, both of these roasts are light - 12.3% WL for the fast-finish and ~13.3% for the slow-finish - but the more tactile, syrupy sweetness of the 20% development ratio profile wound up being more enjoyable to this group. I would also add that this is a green coffee where a fast-finish should be a viable option, and for coffees less nuanced and interesting than this one, the fast-finish approach wouldn’t even be something to consider.

Expect in a handful of weeks a piece on airflow. I’ve been primarily roasting new coffees with existing profiles but am going to hunker down and run a bunch of profiles on Sweet Maria’s new-and-already-sold-out 94 (!) point Kenyan coffee, the Gakui PB lot.