hi guys

got a BT probe installed per randy's method & using hh506ra to monitor. i'm trying to understand how to utilize it to achieve good roasts -- there's this tip on his site i wonder about (hope it's ok to quote):

You want to control the drying time. When the temperature display indicates about 290, start lowering the heating element power and try to hold the indicated temperature in a range of about 300-325 F. Do this by adjusting the fan and heating. Hold the temp in that range until the beans just begin to go from green and begin turning tan. If you do have a bean temp probe, you are trying to get the beans up to about 300 F which marks the approximate end of the drying phase. When the beans hit about 290-295 it is time to turn up the heat.

so if 295 marks end of drying, does it mean as BT probe approaches ~270, i turn down heat, aiming that by the time it reaches 295, they just start to brown, then kick to full force... or is temp on hottop also critical to watch? i've seen reference to ET / MET - i get ET='Environmental Temp'... what's MET? is there a difference? i'm hoping i just have to monitor one display... suffering a bit of data overload

thank you!!

I read that quote again and again and it makes no sense to me. Trying to "hang out" in a certain temperature range sounds like a mistake to me. Instead I'd suggest you try dialing in a roast profile that ramps roughly 20F/min until first crack, then about 10F/min until desired state. Once you've learned you've mastered that, and how tweaking the controls on the Hottop affect the measurements at your bean probe, you can get fancier from there.

See here for ET, MET, and other roasting terms: Roasting Glossary of Terms and Acronyms

Thank you very much rama for terms link & roast method. I have to go re-read now all the MET threads it'll make much more sense... i was guessing 'measured env temp'

tried on some SM brazil yellow catuai -- it was easy to monitor... since i was counting that each degree change took 3 sec before 1C, and once it started tried to keep it close to 6 sec. HT seemed pretty responsive to changes i made, so it didn't take much to make it cooperate.

but made me realize how much lower i needed the heat in the drying stage (i think ended up at P4 or 5). In my other attempts, I tried to follow this guide from another thread on a successful Brazil Formosa roast profile, for 150g batch... but when i had the power as he did, it took much faster than listed here, and made my ramp up be around 40F/min:

P8, F1 @ 24 min. (ET=383 , BT=323 Charge)
P10 @ 21.5 min. (ET=338 , BT=215)
P8 @ 17 min. (ET=424, BT=336)
P7 @ 15 min. (ET=444, BT=376)
P6 @ 13.5 min (ET=455, BT=399 FC begins)
F2 @ 11.5 min (ET=460, BT=416 FC ends)
P5 @ 10 min (ET=470, BT=434)
Drop @ ~9.25 (ET=472, BT=440)

So this attempt i just used his charge temp, but power setting came from following 20F/min guideline...I enjoyed a great aeropress cup now minutes after roasting... we'll see how it tastes in next few days too.

i hope it's a start to more consistent roasts, and the end to cups that just taste weird... especially as they cool a bit (which i think may equal what people define as "grassy", i'm not sure).

thanks again for sharing a simple path for a beginner.