Monday, 28 July 2025

Behmor Roaster - general temps etc

Important nuance to note with your Behmor
The Behmor doesn’t directly display true bean temperature—it shows a chamber/wall temp. 
The actual bean temp isn't the sensor reading & the Behmor temps are nothing like what you'd expect from a standard drum roaster.

The Behmor uses an infrared quartz heating element that heats differently to a gas flame, hot plate, electric coil or air-convection. Quartz light provides near instant heat but unlike most heating elements it heats objects not the surrounding air. The infrared rays (similar to the sun) pass through the air and are absorbed by solid objects.

The Behmor roaster safety button requires users to press the START button  (or C button) within a 30-second window when the timer hits 75% completion (e.g., 2:30 remaining on a 10-minute roast), indicated by a flashing display. Failure to do so results in Error 7 (Err7) and an automatic, forced cooling cycle to prevent fire hazards.





πŸ”₯ Use Temp B (chamber) as your main reference
Why Temp B is better
+ It measures the air temperature in the roasting chamber
+ That’s closer to what the beans are actually experiencing
+ It responds more smoothly and predictably during the roast.
+ The B probe is attached below the drum chamber.
+ Most Behmor roasting guides and profiles are based on Temp B

🧱 Temp A is focused on measuring the exhaust temperature .
Exhaust temps are generally useful for measuring the momentum and total energy in a roaster, however Temp A doesn't seem to measure anything until latter in the roast cycle..
+ It is useful as a secondary safety indicator (e.g. overheating), but not for tracking roast stages.
+ The “A” temperature reading only becomes active midway through the roast when the fan kicks on. 

🎯 Practical takeaway
Track your roast stages (dry end, browning, first crack) using:
Temp B + time + sensory cues (smell, sound, colour)
Glance at Temp A only to make sure things aren’t running away too hot

🧠 Simple rule of thumb
Temp B = “what’s happening to the beans”
Temp A = “what the machine walls are doing”























🎯 Charging/Preheating

Charge temp
On a Behmor 1600 Plus Coffee Roaster, “charge temp” isn’t as tightly controlled as on a commercial drum roaster—but you can still think in terms of a preheat target (Temp B) before you drop the beans.

πŸ”₯ Good starting charge (preheat) temps:
The manual recommends:
 Press any weigh and then Start. Allow the system to run for up to 1:30 minutes. Press OFF,
insert roasting drum, tray and start your roast.

Use Temp B (chamber temp):
I pre heat to 104C-120C (220-250F).

+ Preheat with the chaff collector in (and if possible, the drum too).
+ Load beans quickly
+ Start on P1 or P2 (full or near-full power) in auto mode
    or P5 in manual mode.
Adjust based on goals:
+ Want more acidity / shorter roast → charge closer to 120C
+ Want more control / smoother profile → stay around 100°C

☕ What actually happens on Behmor
When you add beans, temp will drop hard (20–40°C)
Then it climbs back up as the roast progresses
So your “charge temp” is really about:
+ how much momentum you start with
+ how quickly you get through drying

⚠️ Behmor-specific quirks
Preheating too high (>150°C) can:
+ Trigger safety shutdown
+ Increase risk of scorching
As there is no direct bean temp probe → rely on:
+ time to dry end (~4–6 min)
+ time to first crack (~9–12 min)

🧠 Simple rule of thumb
Start around ~120°C Temp B, then adjust based on:
+ How fast you hit dry end
+ How soon first crack arrives

=================================================

🌑️ Dry End Temperature Range

~140°C to 160°C (302°F to 320°F bean temp equivalent)
Many Behmor users track dry end by time + visual cues:
Usually around 4–6 minutes into the roast (depending on batch size and profile)

===============================================
☕ Browning Phase (Maillard Reaction)

🌑️  temp (approx.).. B button
~140-150°C 

πŸ‘€ What to look for
Beans shift yellow → light brown → cinnamon
Smell turns from hay → bread/toast → caramel
Surface becomes more matte and textured
===============================================
πŸ”Š First Crack

🌑️  temp (approx.)
~141°C on the B probe.

πŸ‘‚ What to listen for
Distinct popping/cracking sounds (like popcorn, but sharper)
Beans visibly expand and shed chaff
Aroma becomes sweet, nutty, more “coffee-like”

==================
Afterburners.
Mid way through the roast there will be a temporary drop in the B temperature.
This is normal. The program is designed to have a fan come on to pull air/ smoke through the afterburners to burn off smoke and other impurities. 
When the afterburners come on, heat will be drawn over the beans and away from the sensor thus the reading on b drops.




===========================
Below are 2 examples of standard medium roast profiles.
They are useful guides as to what sort of temperatures the Behmor will read during a standard roast.

The first is a 200g roast. @ 200g setting.
I press the200g button, then P1 button + "start".
Then press P5  (to enter manual mode)
Note that in manual mode, P5 = 100% power.
(Temp: just using the B button - for chamber temp only)
Note that my max temp for this roast is 160C (The Behmor automatically shuts down at 170C)
so one of my goals is to keep the B temperature below this value.

Charge temp: 120C

Time    Temp B
00.00 : 120C (charge)
00.30 : 120C (press P5)
01.00 : 126C
01.30 : 132C
02.00 : 138C
02.30 : 145C
03.00 : 151C
03.30 : 157C (press P4)
04.00 : 162C (press P3)... I dropped temp to P3 to avoid the shutdown feature
04.30 : 163C
05.00 : 160C (@ 5mins the fan will start & the heat will start to drop, so I'll need to increase the power)
05.30 : 146C (press P5)
06.00 : 142C
06.30 : 146C = Dry End
07.00 : 148C (press P4) ... I'm gradually reducing the temp...you can also open the door to cool the roast
                                           Also use fast drum (this mimics air flow in a drum roaster)
07.30 : 148C (press p3)... I'm stretching out the browning phase by making sure the 
                                          temperatures aren't constantly increasing.
08.00 : 147C
08.30 : 142C (press P4)... increase the temp a bit.. stabilise the temp .. avoid crashes or peaks
09.00 : 141C
09.30 : 141C
10.00 : 141C
10.30 : 141C --- First Crack  
11.00 : 142C (you could press P3 or P2 to lower the temp if desired).
11.30 : 138C 
12.00 : 140C... exothermic reaction !
12.30 : 142C
13.00 : drop

------------------------------------------------------------

This is an example of one of my standard medium roast profiles.
This is a 100g roast. @ 200g setting.
I press the 200g button, then P1 button + "start".
Then press P5  (to enter manual mode)
Note that in manual mode, P5 = 100% power.
(Temp: just using the B button - for chamber temp only)
Note that my max temp for this roast is 160C (The Behmor automatically shuts down at 170C)
so one of my goals is to keep the B temperature below this value.
Another goal is to aim for a 50% drying ratio, 30% browning, 20% develop.
So accurately marking Dry End, FC, etc is impt.

Actual Charge Temp : 92C (B setting)
I preheated the drum & machine to 110C but lost some heat when I opened the door & dropped
the beans into the drum.

Time    Temp B
00.00 : 92C (charge)
00.30 : 93C (press P5)
01.00 : 100C
01.30 : 101C
02.00 : 102C
02.30 : 120C
03.00 : 137C
03.30 : 143C 
04.00 : 150C 
04.30 : 155C
05.00 : 157C  - fan kicked on. The A temp is available now.
05.30 : 162C    I pressed P4 to lower temp. 
06.00 : 158C = Dry End @ 5.40
06.30 : 157C 
07.00 : 156C .. I'm gradually reducing the temp...you can also open the door to cool the roast
                                           Also use fast drum (this mimics air flow in a drum roaster)
07.30 : 155C (I could press p3 but the temp seems pretty stable for now)... 
                      I'm stretching out the browning phase by making sure the temperatures aren't 
                      constantly increasing.
08.00 : 155C
08.30 : 142C (press P4)... increase the temp a bit.. stabilise the temp .. avoid crashes or peaks
09.00 : 144C
09.30 : 147C --- First Crack  ?
10.00 : 150C
10.30 : 152C Drop

If you intend to run the full cooling cycle  press "cool" on 1st crack since the roast will continue to develop while the hot chamber cools.

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