More on managing heat...

In the last post I was wool-gathering about heat management at the end of the roast. A little research has helped plug a few holes in my memory.

 I reviewed some of the early roasts I did 17 to 20 months ago. I was certain I did things better 'in the good ol' days'. But the evidence was undeniable- I had convinced myself about the good ol' days, but they existed only in myth. As Merle Haggard reminded us, "things were exactly as I choose to recall". What I saw in the charts, however, was the same collapse in RoR starting at about 1C. Exactly what I'm whining about today it's just that I wasn't conscious of the issue.

I also looked more closely at the greatest difference between a recently cleaned Drum Temp sensor (IR) and the Bean Temp probe (thermocouple). These days I see about 45F° max difference, but over a year ago that max difference was about 65F°. I had speculated that the difference (65F° vs. 45F°) had to do with using higher Preheat, but when I checked those early roasts I saw that I was in most cases using the same Preheat setting of 392°F (there's Merle again, second verse).

Even more disturbing was that I did a terrible job identifying 1C. 1C should be pretty repeatable yet I see examples that are all over the place from 360°F to 390°F. I'm beginning to suspect I can't in any way rely upon Drum Temp (IR) temperature readings for managing the roast. Well... unless Aillio has made a change in how they calculate the value of Drum Temp in the firmware (uh-oh... I think I hear Merle warming up for a third verse!).

More pondering and research required.