Behmor 1600 not keeping temperature

[Mickster]

Andy - HELP!
My Behmor for the last couple of months has been struggling to keep temperature and is under-roasting.
I'm using the temperature probe and 'Roasting Datalogger' to keep track of my roasts.
I pre-heat the oven to 110°C with 450g of beans in the drum (to try to get consistency) set to P2C++++, , after the initial full power it gets to around 250 - 260°C then struggles to hold 200°C for the rest of the roast.
I used to stop the roaster at around minus 1min to attain 50sec of rolling 2nd crack - around CS9 (my preference)
At best now it gets to about CS7 - just gets to 2nd crack. I've even tried shutting it down instead of letting it go through cool down to get some 2nd crack happening, intermittently starting cool down and stopping to turn the drum - I get an inconsistent (mottled) CS9.
I've noted that ambient temperature has an effect, the cooler the day, the more it struggles.
Last few roasts were done at about 14°C ambient. - It's getting cool now in the Adelaide Hills!
All regular cleaning with Simple Green spray and dry burns have been done. I've even taken the covers off to see if it was badly dirty inside - seems pretty clean.

Has anyone else had this issue?
What's the fix?

Thanks in advance,
Mick.

[flynnaus]

I would say ambient temp is what's causing your roasting problems now. Also, 450g is a very large batch size for the Behmor even in warm temps.

I would definitely go for a smaller batch size. On a chilly winter morning in Sydney, I went from a usual 360g batch down to 340 while trying the P2C profile and finding even then I have to add time.

50 seconds of rolling second crack? In my roasting experience, that's more likely to result in CS11 (ie quite a dark roast) rather than CS9. I rarely venture into RSC, usually stopping before.

[JojoS]

Pre-heat the Behmor to 110 degrees Celsius? I didn't it was possible to pre-heat that high and be able to start it.

[sysiphus]

My Behmor is behaving similarly, and has been for months now.
I've been doing 420g (P2C) consistently for the past couple of years, and this has consistently got me to second crack just as it hit the cooling cycle.
Now, however, I've had to reduce it significantly to even get it to rolling first - I'm down to 350G, and max additional time. Ambient temp isn't too much of an issue (or at least, wasn't until last night!) -- Brisbane has been pretty consistently warm all year.

[Mickster]

Pre-heat the Behmor to 110 degrees Celsius? I didn't it was possible to pre-heat that high and be able to start it.

I found if it went past 130°C it wouldn't start... just had to find the max!

[flynnaus]

My Behmor is behaving similarly, and has been for months now.
I've been doing 420g (P2C) consistently for the past couple of years, and this has consistently got me to second crack just as it hit the cooling cycle.
Now, however, I've had to reduce it significantly to even get it to rolling first - I'm down to 350G, and max additional time. Ambient temp isn't too much of an issue (or at least, wasn't until last night!) -- Brisbane has been pretty consistently warm all year.

Have a another look at Update 3 for the Behmor manual that outlines Important Maintenance Procedures.

"Failure to perform this cleaning will lead to longer roast times and possible equipment failure"

[JojoS]

I found if it went past 130°C it wouldn't start... just had to find the max!

Good to know! Thanks!

[kutis]

I found if it went past 130°C it wouldn't start... just had to find the max!

Huh?! What's the number reported from the wall chamber temp? How long do usually pre-heat? I'd be very happy if I can pre-heat to 100º, from my logs it'll be 5-6 mins :S

Sorry, can't help with your original problem. I've been roasting 200g batches. But, I'll try, since the problem is "keeping more heat" after the drop from the P2 profile setting, I doubt it's the batch size issue.

Is the 250-260º max is your usual max? If so, I'm betting on ambient temp. Try roasting indoor, or if you're already indoor, go to a smaller room?

If the 250-260º is lower that your usual max, it might be your electricity...

Or, upgrade to 1600+, technically you can roast even longer...

[JojoS]

I am guessing that the temperature measurements are not taken from the side wall sensor.

[Mickster]

Huh?! What's the number reported from the wall chamber temp? How long do usually pre-heat? I'd be very happy if I can pre-heat to 100º, from my logs it'll be 5-6 mins :S

Sorry, can't help with your original problem. I've been roasting 200g batches. But, I'll try, since the problem is "keeping more heat" after the drop from the P2 profile setting, I doubt it's the batch size issue.

Is the 250-260º max is your usual max? If so, I'm betting on ambient temp. Try roasting indoor, or if you're already indoor, go to a smaller room?

If the 250-260º is lower that your usual max, it might be your electricity...

Or, upgrade to 1600+, technically you can roast even longer...

Hi kutis...
Not sure what happened with my original post???
I'm using Andy's USB temperature datalogger with the thermocouple sitting in a hole drilled in the side of the roaster.
The initial heat up is fairly normal but when the P2 profile sits on 75%, it used to maintain between 209 - 214°C but now barely keeps 200°C.
This does not roast the beans enough to get to 2nd crack in the allowable time.
Power is good - I do roast in the shed and teh ambient temps are dropping - I think this is looking more like the problem than anything else.
I only just read about the upgrade - looks good if able to extend the roast time just a little.
Roasting 1lb (454g) should be doable - seems like many are using less to get teh results they want.
My next step is to bypass the inbuilt controller and rig up an external one that will roast on temperature - not time like this one!

[kutis]

I only just read about the upgrade - looks good if able to extend the roast time just a little.

http://coffeesnobs.com.au/roasters/3...tml#post532674

So, how many minutes did you normally pre-heat so it reaches 100º? I've read somewhere it's 2:30 secs before it can stop without the cooling cycle kicks in...

[JojoS]

I believe that there was a suggestion to get it to 60 degrees Celsius on the the side wall sensor if pre-heating is desired for consistency other than the 2 minute time suggested for US 120V versions. I have yet to try it since it is summertime now in HK have done away with pre-heating. I did 90 second pre-heat last winter when ambient temperature in my kitchen was in the 15 to 18 degree Celsius range.

[kutis]

Hmm, I've been logging starting from minute 3, wall sensor usually reports 69-75º. 60º would be within 2:30 sec ballpark, seems about right. Though pre heat to a certain temp makes more sense for consistencies than time.

Thanks JojoS!

[dlqkdnf89]

Hi All,

I was experiencing the same issue. I have roasted two 350g batches, one on P1 and the other on P2. For both these settings, they both failed to reach 2nd crack. I feel the beans are just baking in there. Was wondering if anyone had an update on what has/hasnt been working. Thank you in advance!

Paul

[Barry O'Speedwagon]

Hi Paul,

A bit more info may help:

P1 / P2 what? i.e. A/B/C? Presumably you've set the weight to 400?

Are you roasting outside or inside? What beans?

Have you tried adding a little bit of time to the roast?

Have you cleaned the fan and exhaust channels?

Cheers