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HG/BM and pre heating...
Cory Nielsen
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Posted on 06/05/2014 5:39 PM
I have read a lot about people pre heating their roasters prior to dropping the beans into the roaster, my question is, with a HG/BM set up should this be done?

Right now my set up is just a standard BM rewired to constant agitation, with a heat gun stuffed down the top, I haven't had any issues getting to SC in under 15 min starting cold. (I have sacrificed some beans in the name of learning my roasters performance arc)
I just don't know if preheating effects the flavor of the beans. Should I pre heat? If so what is the target temp for the pre heat?

In a HG/BM should the roast times be a lot faster then 15 min?

Thanks in advance for any help!

Cory
 
weenie_roaster
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Posted on 06/05/2014 10:22 PM
I imagine it's not very effective to preheat for HG/BM since the heat source is direct-blown as well as the fact that opening the bread machine will release 90% of the heat energy and doing so would lose any preheating benefits you might otherwise gain from fully enclosed setups like drum roasters using radiant heat.
Edited by weenie_roaster on 06/05/2014 10:30 PM
Scott
 
jaywoo
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Posted on 10/29/2014 1:41 AM
I preheat mine, though I've not been roasting long, nor have I tried not preheating. I do have insulation in the form of a fire blanket rapped around the roasting chamber to give it some heat retention. My pre bean drop routine goes like this;
Set HG to around 130DegC at put it in the roasting position while I set up everything else around it.
Now that the thermocouple and software is running I tweak till RoR is flat around 110DegC.
My BM is still stockish, so I have to wait for 3mins till the paddle is fully turning.
With 30secs to go, I remove the HG and set it to the desired starting temp then wait for the BT probe to drop to 100DegC.
Then I drop the beans and add the HG back.
The tipping point is around the 70DegC mark with this preheat. So I'd say it is helping me. I haven't noticed any tipping of the beans either.
farm6.staticflickr.com/5554/14757820347_a1f7f4809a.jpg
https://www.flick...541374907/
 
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jkoll42
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Posted on 10/29/2014 4:20 PM
Hi Cory

Don't get too obsessed with a preheat for hg/bm. Turn it on and preheat for a minute or two if you get the chance but it's not critical. As far as roast time 15 is a little long but not horrible. I've found that for a base profile about 12 minutes is good - drop to 300F in 4 minutes; 300F to 400F in 4 minutes; 400F to finish in 4 minutes. - a little longer for darker fc+ espresso roasts but not much. Hopefully that's right from memory!
-Jon
Honey badger 1k, Bunn LPG-2E, Technivorm, Cimbali Max Hybrid, Vibiemme Double Domo V3
 
Mad Mac
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Posted on 10/30/2014 4:24 AM
jaywoo, what is a cement sheet?
Edited by Mad Mac on 10/30/2014 4:36 AM
 
jaywoo
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Posted on 10/30/2014 5:13 AM
Fibre-cement sheet is another name for it. Sounds like you have found my BM/HG build photos on Flickr. Cement sheet has good thermal properties for it thickness, which is why I used it. In between the cement sheet top and the roasting chamber is a sheet of stainless steel that I cut out of an old clothes dryer. This also forms the exhaust port.
farm6.staticflickr.com/5581/14930399202_731d865c34_z.jpg
farm6.staticflickr.com/5586/14744123810_1f86aedf88_z.jpg
farm4.staticflickr.com/3894/14799827917_f1f624cf46_z.jpg
https://www.flick...541374907/
 
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Mad Mac
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Posted on 10/30/2014 5:57 AM
I wanted to exhaust the internet first before i ask to be considerate.

Nice design. I do believe they sell fiber cement here. On its own, does fiber cement react to the roasting heat?
 
jaywoo
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Posted on 10/31/2014 3:45 AM
I'm not 100% sure but I'm going to say no. The sheet of stainless steel was also intended to form a barrier between the fiber cement and the roasting beans.
https://www.flick...541374907/
 
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