After years of using relatively underpowered electric roasters, I have recently acquired a used Cormorant. As you might imagine, this is quite a new experience for me. After a few mostly undrinkable roasts, I have one drinkable (but not very good), and another that looks like it will be drinkable (will try over the next few days).

The coffee is an espresso blend from Sweet Maria's, which I'm quite familiar with. I was aiming for full-city, hoping to hit 1C in ~9 min and drop in 11-11:30 with 20% development time. I had found this to be a reasonable profile on the hottop.

Here is attempt 2, my first reasonable roast:


I charged with the gas at 25 mbar, and felt like it took off too fast. I was trying to slow things down, but never managed to get it slow enough. There was a bit of a crash at 1C, I assume that this is from going in too fast (other roasts with even higher RoR at 1C exhibited a massive crash, and in one case, a complete stall with RoR < 1F/min). Examining the beans, I think this was dropped too quickly, and was maybe city/city+. The result is rather unpleasantly acidic, although there are no grassy or major underdeveloped flavours. From the description on SM, this is probably to be expected at this level of roast,

Here is attempt 4, second reasonable roast:


Here, I charged at 15 mbar, and soaked until 1 min before increasing the gas to 25 mbar. I think perhaps I cut the gas too aggressively toward DE, and lost too much momentum before 1C. I also went in to 1C a little hot, since I was trying to keep the roast short, so there was a bit of a crash. The roast looks like a well developed FC, but I suspect it will be a bit on the baked side.

Am I going in the right direction? Are my targets reasonable? Is my approach to achieving them going to work (once I can operate the controls a bit better)?

Any and all comments and tips are gratefully received!

Edit - fixed the wrong image for the second roast.

Update - after cupping both roasts, they were actually both pretty awful. Unpleasant acidity, bitter roastiness, and some grassy under roasted notes in one of them.

Will attempt to stay on the gas a little longer in the first half, then cut a bit more in the second half so I get to 1C with a bit less momentum next time.

Thanks for all of the tips and advice. I hadn't seen the thread with Almico explaining his usage of the Cormorant - it was very illuminating, even if he is using much smaller batches than most of us. I hadn't realised that the thermal mass was so low, so will abandon soaking from now on.

I have been taking advantage of my time of work, and got another couple of roasts this morning. Getting better, but not sure if these will just go on the grinder seasoning pile. Fortunately, grocery store coffee can be George Howell for me, so I won't be forced to drink something unpleasant...

Here is today's first roast. For both of these, I set air to 6V and left the damper open all of the time - just making changes with the gas.



I charged lower, but forgot to bump the gas up to 25mbar beforehand. Had to increase the gas toward DE, but was still too slow at 5:30. A bit of a crash during 1C, but not too bad. I suspect this may be baked, as it was generally too slow everywhere - 6:18 from DE to 1C is 50% more than I was aiming for.

Here's the second roast:



Charge was a little higher, and at 25 mbar this time. I was too aggressive again in cutting gas in the middle of the roast, maybe should wait until after DE next time. Should have also made my final gas reduction 1 minute or so earlier, as I did so right before 1C and got a bit of a crash. This one might be drinkable though, only 12 min, but still slow compared to my plan.