I hereby reveal my latest development in the home roasting of coffee beans – a breadmaker and heat gun roaster mounted on a trolley for easy setup and storage.
Previously, I roasted coffee beans with just a bowl, a wooden spoon, and a heat gun mounted on a tripod (I wrote about it here). A heat gun is like an industrial strength hairdryer, blowing out there at 600°C, and it worked very well. It all dismantled and fit into a crate for easy storage indoors, the only disadvantage being the time required to set it up and pack it away.
Recently I progressed to using a bread maker to house and stir the beans – much easier, with greater temperature control and more evenly roasted beans. The only problem was that it didn’t all fit into a crate, and taking all the bits outside and setting up, then later dismantling and storing, took longer than the roasting itself. Because of the smoke and chaff produced when roasting coffee it needs to be done outside, but I don’t have anywhere outside suitable for storing the gear, so the obvious solution was to build some sort of mobile arrangement. These photos show what I came up with (click on any of them to see larger versions).
The first photo shows my coffee roaster in storage mode, as it is when kept indoors. Built onto a box-moving trolley is a wooden platform holding the bread maker, a heat gun mounted on the centre column of a tripod, and the fold-down cooling platform (the toilet seat). Stored with this are the other necessary bits – cooling tray, power board, extension cable, multi-meter with temperature probe, stopwatch, oven glove, wooden spoon, fold up stool, and a sweat band (it can get hot when roasting). The only thing not housed on the trolley is the fan: that’s because it gets used elsewhere for other things.
The second photo is roasting mode, seen here inside my garage. Hot air from the heat gun blows onto the beans being agitated inside the bread maker, with the bean temperature being measured by a probe inserted into the side. Temperature is adjusted by moving the heat gun up and down. The fan reduces the stress on the heat gun element while also blowing away some of the chaff.
The third photo shows cooling mode. Once the beans are done, the fan is laid down on its back, a mesh cooling tray is placed on top of the fan, and the hot beans are poured onto the cooling tray. It only takes a minute for the air blowing upwards through the beans to cool them down completely. After the removal of the beans and a quick bit of unplugging and folding up, the contraption is ready to be wheeled back indoors until next time.
Why the toilet seat, you may ask? I needed some method of supporting the fan in its laying down position – something to keep it up off the ground to allow good airflow, with plenty of open space in the middle where the fan draws up the air. A toilet seat performs this function perfectly, without modification. It even came with its own built-in hinge so it could be folded up for storage … and being a guy, leaving the seat up comes naturally to me.
Apart from the bread maker (which I picked up second-hand from a pawn shop), I didn’t need to spend anything on this mobile coffee roaster. I already had the trolley, the bits of wood and other parts, and the toilet seat was been sitting around for at least 10 years waiting for another chance at life. It all supports my belief that nothing potentially useful should be thrown away in case it might be useful one day.