So I've taken the fork in the road toward the heat gun/bread machine (HG/BM) approach. Today I destroyed a perfectly good bread machine ($25 on Craigslist) in the attempt but may yet modify it into a workable roasting chamber. Just when I thought it was going to work, I ran into a few problems with melting plastic and a display message of HHH (Hot! Hot! Hot!). The plastic case on the HG also began to melt but stopped short of anything more than cosmetic damage. Here are my first efforts.

Summary before photos and captions:

My first try was to prepare the HG/BM for roasting. Target temperature while sustaining agitation was to simulate Jim Schulman's espresso roasting profile. I've added Celsius numbers to match my thermocouple (TC) reader:

another_jim wrote:0 - 1 min to 250F/121C (basically top speed)
1 - 4 min to 300F/149C (drying phase, an absolute must)
4 - 7 min to 380F/193C (top speed again, the longer you're here, the worse it tastes)
7 - 11/12 min to the end, 11 for brewing, 12 for espresso (balance fast vividness and slower sweetness)

Here are the modification and testing steps taken today in summary. I'll give details with the photos:

1. Removed glass from BM top.
2. Attached thermocouple inside case next to bread basket.
3. Inserted HG in foil holder.
4. Turned on agitation while running HG to roasting temperature for about 5 minutes. Machine kept agitating throughout but started with pulse.
5. Noticed melted plastic around top door of BM.
6. Got HHH display on BM after turning it off.

Here's the BM almost untouched.



I had just started to try and drill a starter hole and wondered whether I was dealing with hard plastic in the window or glass. I had to switch to a carbide tip and began suspecting glass, but I did make a divot.



Then I switched to a routing tip but still wasn't getting anywhere and noticed the glass started to chip away.



So I put a cardboard backing behind the window and prepared to knock out the glass with a masonry chisel and mallet. I put on safety goggles for this step. This immediately broke the glass, and I picked out all the shards I could see with a pliers. But I could still hear glass rattling around inside the door.



So I removed the metal liner, which was held in by tabs, and removed all remaining bits of glass, also carefully cleaning the agitation chamber and work area.



Then I placed the K-type TC, wrapping it around the heating element in the BM.



I placed the HG and turned on the BM for its dough setting, which adds no heat but agitates.



I watched the TC reading and found I got to the top end of the target range after about 5 minutes. The agitation continued unabated, so I thought I was ready to try some actual roasting. But I smelled something funny. I then realized it wasn't a break-in smell from the HG but instead it indicated significant melting plastic around the HG insert.



I lay the heat gun down and then noticed a wisp of smoke coming up from it. And I found that its case had also started to melt with this insertion setup. NG (no good!)...



I then turned off the BM and it immediately displayed HHH, indicating overheating. I don't know yet whether this means the agitation will stop when I get up to temperature, but I don't want to waste a pound of greens finding out!

So at this point, I'm left with the problem of how I can mount the HG without melting the BM and the HG itself. I'm open to any suggestions! (Later: I wonder whether others have used BMs with a metal case so mine just may not work?) If I can create a good mount, then I'll heat test the HG/BM again to see if I avoid all melting this time and whether the BM keeps agitating or whether the agitation stops because it senses overheating. But I'm not there yet. It may keep agitating. However I notice that the agitation starts in pulses and then becomes constant. I'll have to search the user manual to see whether there's a constant agitation setting and if not will determine whether that makes a difference in the roast, because it stirs the beans. If the roast is uneven, I'll have to follow jammin's example:

jammin wrote:I have since "gutted" my bread machine. All the electronics have been removed and the motor is direct wired for constant stir. This is nice because I don't have to wait 5 minutes for it to quit "pulse" stirring and go to constant. I also don't have to worry about the thermostat telling the machine it's "too hot" after a roast. I would often have to wait for it to cool down before it would start again - plus the 5 minutes of pulsing. This may have partially been due to the extreme temps. here in Baghdad though.

Yow! This is hard enough to do in California summer temperatures!

Note that at upwards of 450-500 degrees, the teflon in your bread maker pan (if so equipped, and almost ALL of them are) will release toxic gases.

The gasses will only make you sick, but if you have a parrot, and you overheat teflon indoors, it is very likely they will die. Birds have very sensitive respiratory systems. This is one reason I haven't gotten into BM roasting.

When I use a HG, I do it in a fry basket nestled inside of metal bowl, and shake the basket to agitate the beans.

allon wrote:Note that at upwards of 450-500 degrees, the teflon in your bread maker pan (if so equipped, and almost ALL of them are) will release toxic gases.

How can you tell if it's Teflon coated? Mine doesn't have the black coating you find on Teflon pans.

Still, though, even if I take the plastic door off the top, leaving only the metal liner as a mount, there's plastic adjacent to it that can't be removed without removing the whole control panel, so it's still vulnerable to melting, and I'm not eager to breathe in those fumes either.

And yet I'd still like to be able to have an enclosed roasting chamber with sensitive temperature readings. I know, buy a Hottop!

Clint Orchuk wrote:You, gentlemen, are hard core

Yeah, true.

So I just wanted to roast today, right? Get too picky with the method and I can miss out on just living! I took Allon's lead and just let 'er rip with the HG, a colander and sieve. It's coffee, it's past first crack, it ain't burned, and it took about 13 minutes roughly following Jim's guidelines.

Hopefully luck was with me today. My wife noticed three four-leaf clovers in our garden. Here are two of them. I've never seen these before .... OT? Sure, why not?



Oh yeah, roasting. Here are the greens:



First tried them with the heat gun in a colander.



They were hard to agitate so after 30 seconds I moved them to a sieve.



I placed the sieve in the colander and blasted away but noticed it took a little long to get through the yellowing phase, about 5 minutes. So at times I had to almost bury the end of the heat gun in the beans, actually had it about 2 inches away. Next time I'll use the sieve in a metal bowl without holes to conserve and spread the heat. But the roast was already underway, and with some improv, here's what I had after 13 minutes.



It took about 5 minutes of tossing and stirring to cool them down enough for easy touch. There were some light ones I culled out. Into a Mason jar, and now I'll wait a few days and see what I've got. Enough technology already, this doesn't have to be so hard!

Later add: A few days later, this roast was too "bright." 12 days later it was quite nice and chocolaty in an AeroPress.

Gary,

The plastic part of my lid started to melt when I first gave things a try as well. Just pop the metal interior part out and leave the plastic part up. You can use the plastic lid to rest the gun and the metal part to close off the roasting chamber and support the gun. Here is a pic of how I do it:



Notice the plastic trim ring on the heat gun nozzel has been removed. Just twist it and it will pop off. You don't need to - but just letting you know it's really easy to remove.

I'll give you 10 to 1 odds the thermostat is just on the other side of the chamber screwed onto the sidewall(by/below the contol board). Popping the casing off of your BM is a bit of chore, but pulling the thermostat off the sidewall is piece of cake. Be warned, you might become very tempted to continue gutting the roaster at that point and hard-wire it for constant stir

cheers,
~j

Jackson, I was hoping you would find this and chime in!

jammin wrote:The plastic part of my lid started to melt when I first gave things a try as well.

Why didn't you tell me? I'll have to look again though and see if the plastic near the control panel is still too close and needs trimming or something.

jammin wrote:Notice the plastic trim ring on the heat gun nozzel has been removed. Just twist it and it will pop off.

I'll try that.

jammin wrote:I'll give you 10 to 1 odds the thermostat is just on the other side of the chamber screwed onto the sidewall(by/below the contol board). Popping the casing off of your BM is a bit of chore, but pulling the thermostat off the sidewall is piece of cake. Be warned, you might become very tempted to continue gutting the roaster at that point and hard-wire it for constant stir....

Mine is DC I think. Do you know how to direct wire it if I post pictures with the case off?

allon wrote:... upwards of 450-500 degrees, the teflon in your bread maker pan (if so equipped, and almost ALL of them are) will release toxic gases.

Thanks again for the heads up. I'll scratch the inside and see if there's a coating. If yes, it'll need to be polished off with my rotary tool.

Here are some pictures for a better look at how this BM might/might not be modified. First, though, I took another look at the bread chamber and it isn't coated, so no worries about Teflon.

But you can see my concern that the control panel's plastic edge is right next to the bread chamber.



and you can see it started to melt.



Here's a look at the thermometer and heating element connections in the bread chamber, next to the control panel.



And here's a look at the electronics. Are the blue wires the thermometer leads?



Later: Here's a close-up of the electronics: