I have been roasting beans for a long time using a Popcorn Pumper and that really only roasts enough for two pots of coffee. I finally managed to get a large commercial coffee grinder (Grindmaster 875) and was looking for a way to roast enough coffee for an entire week. After scouring the web I decided to use a heat gun and was going to make a stirrer basket when I came across the Correto method link 1
and link 2
using a bread machine.
It took awhile but I finally got a bread maker for $15 off Craigslist. It had pics and all that jazz, but turned out to be very dirty and required disassembly for proper cleaning. Before doing too much I ran it to see how long the cycle was since most of the heat gun bread machine methods speak of 10-12 min. It turns out the motor cycled on and off for two minutes and then was on for 50-55 seconds of every minute for the next 5-6 min. Not quite enough to make a batch and it would be a real PITA to have to stop and restart the cycle.
Anyway, took the machine apart, cleaned and killed a few crawlies (yup, it was that nasty inside). Thought about calling the previous owner and telling them to exterminate, but figured they had to already know. After cleaning played around with the circuit board and inadvertently crossed two wires and tripped the circuit breaker. After figuring out I had fried the board I decided to take the thing apart so I would know more about them the next time I found one on the cheap.
The motor was 110VDC and I disassembled it completely. I thought about direct drive and looked at motors online and could not find a replacement. I spoke to an electrician and he said I might be able to run the motor off household current by using a bridge rectifier
since the voltage was simply a swap of AC to DC. I found one at Radio Shack
for $2.59. Since that sounded like an easy test I drove to RS and got one and it worked like a champ. In case the motor was only rated for intermittent duty I ran it for 15 minutes and it did not heat up at all, that may not be the case with a full load of beans, but the motor is real close to the bread baking chamber so it must be slightly immune to heat.
With the bread machine gutted I reinstalled the heat shield, but the only electronics that remain are the cord and motor wiring. I left the heating element in place since it seems to add rigidity to the baking chamber.
Of course I had to try a small test roast. I followed the instructions I found here
and the pictures here
and from the Corretto links I had seen a fan setup to blow the chaff away from the bread machine so I set it up that way.
I found a little over a cup of green beans which turned out to be a little more than 6 ounces by weight. This seemed like a good amount to try out the setup since it was more than the capacity of the i-Roast 2. With the digital heat gun
on the highest setting I was afraid I would not hear the 'cracks' due to the BM and HG noise combined so I backed down. Turns out I should have kept it up full blast and closer to the beans since my total time went nearly 15 min for the test roast. I could hear the cracks plainly and it was a piece of cake to back off and move around for an even roast. I cooled the way I always have by putting the beans into a colander and spritzing with a spray bottle of water.
Anyway, the two photos are my results, one with the flash and the other without. I figure this is just about midway Full City roast.
So the bread machine was $15, the heat gun was $40 and the bridge rectifier was $2.59. So my total out of pocket was less than $60 and I can use the heat gun for other things. Not bad for a Super Roaster!
The old Toastmaster Breadmaker has become the Roastmaster Coffee Bean Agitator