Hey folks. I am experiencing a situation with my roasting conditions. TL;DR is this - I need my BT Probe Drop temp to be 200C - but IBTS at 310C (max) wont get it that high from cool - Should I blind roast for a minute or so for the heat to get high enough and then go through Preheat again??? (I use BT for my batch size, im a probat user when i was working in a larger roastery - IBTS is great, but not my main marker)
Explanation - I preheat my roaster to 300/310C on the IBTS (Max setting) which yeilds a 185/190C drop temp (from cold). however, after 2 roasts, always get my BT probe to 200C without fail (Solid Heat in the drum and surroundings)
My recipe for a Brazil requires 200C drop temp so it doesnt legnthen the Maillard and overall roast (cool start with high energy P9 - adds an extra 45 to 1 minutes)
How many minutes do you preheat the first time? If you preheat for about 20+ Minutes to begin with (even if you get the Charge Prompt in between), the BT usually does go up to 200C and beyond. In fact in my case, it is the second back-to-back roast that does not have as much momentum as the first roast.
I usually just aloow it to go to the charge prompt. I dont think I have let the roaster sit idle when the Charge Prompt takes place, but looking at the way it still fluctuates between power settings to float the temperature, and by what you have said, I assume I can just let it idle until I reach my temperature?
The charge prompt based on some internal algorithm does not always ensure a fully heated drum, so (based on earlier discussions that have happened), quite a few of us keep preheating beyond the prompt till our required BT is achieved. Hope this helps.
As Cash suggests I long ago started using B-Temp to determine when to Charge the 1st roast. B-Temp is strongly influenced by the front plate during Preheat. The probe gets a small amount of radiated heat from the drum plus a lot of conducted heat from the front plate. So until you do the 1st roast there is no quick way to get heat from the inductively heated drum into the front panel and then to the probe.
The quickest way is probably a throw-away roast but at $8/lb (or more!) I’m not willing to do that. So I wait on the order of 45-60 minutes to charge the first roast.
As an aside, B-Temp is what I use to Charge the roast (about 302-305°F on #2 or later); I-Temp I use to manage the roast once it gets back on-screen. I could scale the Right axis to keep it on screen but that doesn’t offer sufficient resolution for managing a roast.
Note: I’m roasting on an R1; not sure how applicable these comments are to an R2 roast.
Just struck me: since I-RoR goes off screen initially I wonder if RT4 could be modified to use log scaling for the Y2 (right) axis only… ?? That would make it possible to keep I-RoR on-screen for the entire roast plus expand the scale at lower values to make it readable. Yeah, the non-linear display might drive some users crazy (it would have to be optional) but it would be a real plus to have continuous display as an option.
I’d probably be alright with the non-linear graphing but I can imagine all the ‘it doesn’t look right’ whining. Did I ever mention I’d never want your job?!
SE Arizona is heating up as summer creeps closer and closer. It’s a balancing act surviving late spring heat until monsoons (our desert-version of what you see) begin about 6 Jul. They aren’t much but they make it survivable here. About 200 miles NW of us in Phoenix, Arizona they don’t see the monsoons and have recorded temps as high as 137°F/58.3°C. Not fit for humans… which must be why that’s where all our Arizona state politicians work.