Great profile. Excellent that you got to this result.

For kicks I tried a 1# roast to see if I could do it on this roaster. Good news...it works. Not the prettiest roast, but clearly I'm getting usable data from the BT probe:



Here's a vid of the action. I wonder if I can get 1/2 a pound.

Did some roasting last night. Man I love roasting 8# at a time. I did in 90 minutes what would have taken me 3 hours before.

Starting to get a grip on the roaster now that I have the power up. It's nice having excess BTUs and I'm starting the get the sag out of the RoR curve.

Here are a few profiles:

Hi Alan,
Thanks so much for sharing your journey, I've really enjoyed following along.
You have really started to dial in your curves but I still notice a slight rise at first crack. I know you have mentioned that your reluctant to adjust your air flow but I would be curious to see what would happen if you stepped it up just a bit at 1C. Would that help level things off a bit without sacrificing the end of the roast?

Alan,

What do you use for your espresso? How's it coming out on the drum versus the air roaster?

Thanks,

JB

stew wrote:Hi Alan,
Thanks so much for sharing your journey, I've really enjoyed following along.
You have really started to dial in your curves but I still notice a slight rise at first crack. I know you have mentioned that your reluctant to adjust your air flow but I would be curious to see what would happen if you stepped it up just a bit at 1C. Would that help level things off a bit without sacrificing the end of the roast?

Rao suggests in his blog to try and avoid touching the heat +/-45s on both sides of 1C. And just when I think I have a nice downward RoR going before that point, I get a plateau. I might have to try and reduce heat even more in anticipation of this, but I'm running out of needle valve on the bottom end. That's the problem with getting more BTUs at the top.

I'm already at a pretty brisk airflow rate throughout the roast. I'm afraid opening the air during this 1C window would have the same affect as turning down the heat. I'm afraid of causing a big crash. As is, I'm not getting big crashes with these profiles. And I don't want to open the air and then close it just to trick the BT curve.

My issue with darker roasts is trying to maintain the AOC high enough to get 2C. If the RoR falls to low, I lose the high temp I need to finish the roast.

Moxiechef wrote:Alan,

What do you use for your espresso? How's it coming out on the drum versus the air roaster?

I use a Brazil/Sumatra/Costa Rica/Ethiopia blend for my espresso and haven't noticed a big difference from air to drum in taste. It's harder to get into 2C with a smooth declining curve with the drum. Lighter roasts are much easier than darker. And when I say darker, my espresso is technically a medium roast at 52/56 Agtron.

Almico wrote: I'm already at a pretty brisk airflow rate throughout the roast. I'm afraid opening the air during this 1C window would have the same affect as turning down the heat.

If you turn up the air at the end of the roast you will likely see an initial increase in delta bt while you burn off the stored up heat in the hot surfaces followed shortly by a crash

My first 10# roast. It felt like the little engine that could watching the RoR climb. It made it though. I let it get away a bit before 1C, but a good roast nonetheless.

Nice temp management. Do you enjoy the flavor of that profile?

I do. It's a nice medium (52/56 Agtron) espresso roast. I'd like to get the hump out, but I find if I drop the heat to eliminate the hump, the RoR starts down as 1C begins and I can't maintain enough temp to get into 2C. It's quite the balancing act.