Feedback on Yirgacheffe Roasts- Cormorant CR600

Discuss roast levels and profiles for espresso, equipment for roasting coffee.

#1: Post by portermoab »

Hi All- first time poster here. I've been roasting on a FreshRoast for a few years and recently converted to a Cormorant gas roaster. I've been working with a washed Yirgacheffe Chelbesa Danche from Sweet Marias and have struggled getting a great, classic Yirgacheffe flavor profile. (Note that I've read through all of the existing Yirgacheffe roasting posts)

I'm including the last two Artisan profiles (#8 and #9) and I'm looking for some feedback on what I could be doing better. Roast #8 was not very good, heavy with some baked flavors. Roast #9 is quite good and getting closer to where I want to be with this bean. Some Earl Grey/bergamont flavors. Both coffees had very little by way of wet aroma (not strong or of a particularly high quality). Primary roast differences are as follows:

Charge 420F
1 min soak, gas off
Goals for this roast was: >5 min. DE, 3:30-4:00 Maillard, FC @ 9:00 (+1:30-2min. drop); approx. 10:30 total time

Charge 410F
30 second soak, gas off
Based on the not great results of #9, I wanted to extend Maillard a bit and try to come into FC with less heat
Goal was: >5 min. DE, 4:30 Maillard, FC @ 9:30 (+1:45 drop); 11:15 total time

Thanks for any feedback!



#2: Post by Milligan »

You are cutting gas too early causing a droop in your curve during Maillard. I don't cut until DE on most roasts and sometimes not until 315F for roasts going through FCe. A good place to start dialing in is Rao's standard gas control scheme which translates roughly to the Cormorant as:

380-400F charge at 45-40mbar gas
@300F gas to 35mbar
@325 gas to 28mbar
@340 gas to 21 bar
@360 gas to 15 mbar
@372 gas to 10 mbar
Cruise through FC
Drop gas to 5/off as RoR drop ease to get to drop

Air to 7-8 the entire time

That was translated from Rao's roasting manual and has been a good place to start on many lighter roasts.


#3: Post by Milligan »

Here is what that profile looks like on a Yirga coffee I did recently. This one was a light/medium so pull it earlier for a lighter roast. This one likes to bump a bit during FC, so getting it flat there was an accomplishment while still keeping enough heat to get it to my desired roast level. A lighter roast was easier to control. I'd do 5mbar instead of 10 to reduce the FC plateau but would end up a light roast. Obviously our conditions may be different but at least this gives you a place to start.

The control scheme was translated from "Coffee Roasting Best Practices" by Scott Rao page 45.

portermoab (original poster)

#4: Post by portermoab (original poster) »

Thanks. I'll try this approach out. I actually have that Rao book on order, which I'm looking forward to digging into.

Looking at your profile, are you soaking? If so, for how long and with gas off or reduced? The profile you sent looks like you didn't hit the gas until almost 3 minutes into the roast, which probably isn't accurate, right?


#5: Post by Milligan »

I forgot to mark the initial gas until further into the roast. I didn't soak this one. If I'm apprehensive of scorching I'll do a lower gas until the TP. Usually around 20mbar or so. Cormorant has a lot of heating power. We've had a few discussions about soaking with the Cormorant. Some do it, some don't and some start with low gas. Depends on the coffee and your preference. Starting with lower gas until TP does help prevent tipping.

portermoab (original poster)

#6: Post by portermoab (original poster) »

Thanks again. Just did a roast generally following those guidelines and kept everything pretty on target (and avoided the Maillard droop I was getting before). I did a 30 second soak (gas off) with the fan at 5 and then came in with 45 mbar, trying to hit the temperature targets as I dropped the gas. I charged at 400F as I'm in a 50F ambient space right now and was worried about charging too low. No scorching or tipping. I got a bit of a dip into FC, so I may have wanted to let it ride at 10 mbar a bit longer instead of cutting to 5 mbar.

Obviously it will all be more clear tomorrow when I've had a chance to cup it, but I'm liking the look of the roast as compared to previous efforts. Any further feedback would be appreciated.



portermoab (original poster)

#7: Post by portermoab (original poster) »

Also, based on my understanding of Rao's approach for ET/fan speed, I think the fan at 7 was way better than at 6. I got a nice flattening ET towards the end as opposed to continuing to increase through FC. I believe his take is that the proper fan speed will essentially flatline your ET towards the end of the roast (assuming you're not running into SC).


#8: Post by akirapuff »

Im roasting on a cormorant and if I follow those heat settings at 454 gram batches, I'll hit fc around 7 mins and flick and crash. Are you in a colder climate? For most roasts for me starting at around 30mB and dropping from there is plenty of heat for most type of beans. No soak.

portermoab (original poster)

#9: Post by portermoab (original poster) »

It's winter where I live, so the ambient temp of the shop I'm roasting in is usually around 50F. Even at 400F charge with 45mbar I'm still barely getting to DE under 5 min. I'll definitely have to start dropping charge temps as it warms up, and may do some more experimenting with that now, too.


#10: Post by Milligan »

Winter here too. Gas settings can change a bit from machine to machine and environment. It is mostly about the appropriate draw down on gas as you approach FC and the step down a bit after for your situation. The OP was drawing down early, so my settings were shown to give something to go off of. The exact settings need to be found by each person individually for their setup.

That roast is the fastest I'd do on my machine. I sometimes do a 20mbar low gas at charge until TP then 40mbar to DE. I roast in a basement that stays around 64-68F with relatively low humidity. My beans start around that temp too.

Curious to hear how the roast tastes from the OP. That little flick at the end isn't too bad since it was dropped quickly. Much closer than the first graphs posted. A little tweaking and I think you'll be in good shape.