Author Topic: I wanna build a new roaster, but ....  (Read 6935 times)

Offline stevea

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Re: I wanna build a new roaster, but ....
« Reply #15 on: May 23, 2017, 06:16:25 PM »
Hey Peter - that's actually a good idea.

I did mod my SC/TO to vent some air, then tried to duplicate the profile on my "closed" system.   If you taste the cooled whole beans (just suck on a teaspoon full) then you can taste some difference.  It's harder to tell in the pot.

I bought a halogen TO, and so far my first attempt failed.   The temperature limiter kept kicking in as I approached 1st crack.  So I switched to my standard GG to finish the lot.  What is genuinely weird is that the half-halogen'ed beans appear to be much smaller than the same beans conventionally roast.   It might be due to the 'switchover' profile problem, but these beans clearly didn't expand as much as expected.  They do taste good - no problem there.

By next week when I roast again I'll defeat the over-temp switch and try a fair side-by-side of the same beans halogen vs hot-air TO.

 
"Never put off until tomorrow what you can do the day after tomorrow."  — Mark Twain

Offline peter

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Re: I wanna build a new roaster, but ....
« Reply #16 on: May 23, 2017, 09:48:32 PM »
Sounds like you're havin' fun, Steve!
Quote of the Day; \"...yet you refuse to come to Me that you

Inabcentia

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Re: I wanna build a new roaster, but ....
« Reply #17 on: July 05, 2017, 07:25:02 PM »
Stevea, how did this project finally turn out? Did you build a new roaster?

Offline stevea

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Re: I wanna build a new roaster, but ....
« Reply #18 on: November 07, 2017, 11:45:19 PM »
Well - I stalled on the new roaster design, but I finally have continued with the halogen SC/TO.

The halogen TO I have came from Aldi's ~$30 IIRc0, is rated at 1300W,and aside from the heating element and plastic knobs, is close cousin to my conventional 1430W GG.   The relay based thermal cut-out had to be defeated, otherwise it kicks off in the middle of a roast.

So among differences - the old SC would release smoke between 1st & 2nd crack, but the halogen unit seems to burnoff the smoke.   My garage is a LOT less smoky.    If I stall the halogen heater to add some rest time late in a roast - then I get smoke.

Same beans take 30-40 seconds extra to hit 1st crack in the halogen system. I suppose I could attribute that to 1300W vs 1430 watts.

The resulting coffee is notably brighter,  a notch more brightly acidity, despite having very similar color and a longer roasting time !  It's on the edge to 'too acidic' and holding onto varietal flavors of nut & fruit well - and this is a touch into 2nd crack.

So far the glass on the TO is only discoloring/fogging on the OUTSIDE of the springform holder, and a cursory inspection the halogen element looks clean.   I've only put ~4.5lbs of greens through it, but the halogen heating method looks very promising so far.
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As an aside I rather gave upon fluid-bed after correcting my calculation of re-coverable heat. Too inefficient. That leaved induction heating and various forms of light/EM.


"Never put off until tomorrow what you can do the day after tomorrow."  — Mark Twain

Offline ptrmorton

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Re: I wanna build a new roaster, but ....
« Reply #19 on: November 08, 2017, 07:34:34 AM »
Thanks for the update stevea.  I'm always curious about this sort of thing.
AZ Peter

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Offline stevea

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Re: I wanna build a new roaster, but ....
« Reply #20 on: November 08, 2017, 09:05:38 AM »
I see over on homeroaster.org in the recent months some aussie guy is building an (IMHO) too complex contraption of strainers and pots and wiper motors with a similar halogen turbo-oven on top.  Still he claims similarly good results from halogen heating.
"Never put off until tomorrow what you can do the day after tomorrow."  — Mark Twain