I understand different roasters operate differently, but I see broad similarities from multiple sources about what BT should be at certain points. The drying stage for the M3 seems to be spot on, but after that everything is out the window. It seems 400F or 205C is the agreed consensus for 1st crack. My roast reaches 1st between 185C and 190C. At 205C the roast would be on the verge of 2nd. What makes the M3 so different? Does reaching 1st crack earlier than other roasters effect the flavor?

I rarely mess with 2nd crack. I might have reached it twice, both times on accident. I haven't reached 2nd crack since I've been data logging so I don't have any data about it. What temperature does the M3 normally reach 2nd crack?

I'm reaching 1C at 195-198*C and then 2C at around 223*C. I have a Quest M3 with Amprobe TMD-56 with standard BT probe placement.

Those are my numbers as well - I usually reach C1 between 195°C and 198°C. I don't datalog but I make notes and use Eric's thermocouple at his suggested location - under the tryer on the left side.

FWIW, I usually pull my roasts at a BT of around 212° - 215° (about a 20° rise from C1) which reflects a City+

195C to 200C for the first crack for me as well

I'm using a modified thermocouple provided by Eric. At my request, Eric modified the BT thermocouple to go through the screw holding the viewing glass in place. At the time there was no thermocouple adapter for the original placement. I have one now but have yet to use it. Mainly because I don't have the right thermocouple for that placement. My current placement penetrates the bean mass adequately. It stops right before the fins. Is that deep enough for a good reading? I thought the placement would be more accurate. Seems like I need to rethink that decision, or possibly just add another BT thermocouple. One advantage to the current placement is when I pull out the trier the BT does not drop at all. If I recall correctly, the BT would drop when I pull out the trier when I was using the analog thermometer in the original BT placement.

With the stock thermometer, I often see 1c around 180-185C. With a thermocouple probe, I see it around 195C (like many many others). [I didn't do real calibration on either the thermometer or the probes beyond just room temp.]

FWIW, I just use the offset from the agreed upon 1c and/or the change in temp from where I observe 1c. That makes it easier for me to ignore probe offsets, bean surface temp versus bean internal temp offsets, etc.

Marshall_S wrote:Those are my numbers as well - I usually reach C1 between 195°C and 198°C. I don't datalog but I make notes and use Eric's thermocouple at his suggested location - under the tryer on the left side.

FWIW, I usually pull my roasts at a BT of around 212° - 215° (about a 20° rise from C1) which reflects a City+

+1

I suspect there is another variable, the type of bean being roasted.

I have a devil of a time hearing FC but SC is loud and clear, on some roasts, and other beans the FC is louder. Temp at FC might have something to do with noise.