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.
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.