tracking Temperature on a Behmor

[rionato]

I have had my Behmor for about 4 months, and I have been very pleased with my results.
But, I want to start really perfecting my roasts. Is there any way to monitor the internal temperature?

[yakster]

This is pretty easy to do with a thermocouple like the one that Tom sells on this page and manually entering the data into the BehmorThing program for PCs. This is what I do.

There was a rumor that Ira (the author of BehmorThing) might be working on a USB thermocouple that would automate this in the future.

I used to have the thermocouple taped to the ceiling of the Behmor just to the right of the light, but after I took the thermocouple to work to check a microprocessor temperature issue, I now snake it along the bottom of the Behmor pointed up at the back just below the bottom heating element. I use 3M's Scotch 5413 high temperature film tape to secure the probe, tech note available here.

Now that you've got temperature available, the next question is what you can do with it. From the vantage point of the two distinct areas in the Behmor that I measured temperatures, I can say that I don't have a good picture of what is going on inside the whole Behmor. I can see when the heaters are kicking on, but with the airflow and the drum, it's hard to say what the temperature the beans are seeing. I read about some Behmor enthusiast who snaked a thermocouple into the drum by drilling out the side and inserting a tube on the left to enter the drum... this is a little extreme for me. Besides, without seriously moding your Behmor, you can only adjust your profile for the next roast and not make any roasting corrections (besides maybe cracking the door or hitting cool) with the realtime information you gather.

Having said that, I do think that I've learned more about how the Behmor roasts and working with BehmorThing understand how to better program my roasts, and I've really enjoyed looking at the data (if your that kind of person). It also gives me something to do (log the temp changes every 20 degrees during the drying and cooling ramps, and at finer increments when approaching first crack) during the roast that keeps me engaged and paying attention so I don't have to worry about the roast getting away from me.

You can see some of my temp logs in my roasts on my photobucket page.

-Chris

[curlyjim]

I think the data is useful. You do have a few points for reference.

Beans turn yellow about 325F
At 1C beans are around 400F
At 2C beans are around 440F

Compare your recorded temperatures at these reference points and see if there is a consistent or predictable difference. If so, then you might be able to surmise bean temperature at other places, at least roughly.

I just started using a thermocouple with my Behmor, so I haven't really figured out if this is accurate enough to be useful.

Curlyjim

[jrgumby]

Anyone messed with drilling through the left side of the oven and through the center of that peg to allow the thermocouple to be inserted into the bean mass and read bean temp a bit more than environmental temp?

[yakster]

I saw this post on Home-Barista where Farmroast did just that, but I haven't taken that step yet.

Once you go there, the next natural step is a full manual mod to allow you to respond in realtime to your measurements. I'm not quite ready for that level of modding, time, and expense.

-Chris

[Dthomas]

I used to have the thermocouple taped to the ceiling of the Behmor just to the right of the light, but after I took the thermocouple to work to check a microprocessor temperature issue, I now snake it along the bottom of the Behmor pointed up at the back just below the bottom heating element. I use 3M's Scotch 5413 high temperature film tape to secure the probe, tech note available here.



-Chris

Chris, if you have a TC inserted into your Behmor, than my USB datalogger and software system would work with it. http://homeroastprofiler.blogspot.com/ is the blog I just started about it. I was wondering how my unit might work with a behmor, its good to know a TC can be used with it's design.
There is also a thread about it on this forum. viewtopic.php?f=5&t=580

I'm trying to make it better, so feel free to let me know what other info might be handy.

Good luck!

[Gregr]

I hope it's not bad form to bring this thread back to life instead of starting a new one. I decided to bring this one back thinking that the folks that use a thermocouple with the Behmor will be more likely to see this and respond.
What I'd love to know is can you simulate the P2 power drop by opening the door? Or for that matter, have you come up with any sort of rough guidelines on how much of a temp drop you get by opening the door for say, 30 seconds for example? I know the ambient temp of the roasting room will be a significant factor. I find myself opening the door on just about every roast trying to lengthen the time between cracks.