A Coffee Roastery

[I plan to write a more complete article with pictures at a later date. For now, this.]

I have peculiar taste in coffee, at least when compared to what’s readily available in the local area. I have thus far failed to find a reliable, affordable source of roasted coffee beans that suit my particular predilection. My wife suggested I try roasting my own.

I’ve known a few people that have roasted coffee beans for their own use with excellent results — and significant investment of time and effort. I had been unwilling to enter this rabbit hole. After continued (albeit mild) frustration and some encouragement, I’m diving in.

Based on the experience (and success) of some good friends, I’ve opted for a bread machine + heat gun roasting configuration (aka “Corretto”): it provides a good ratio of control and consistency to cost. Additionally, I’ve taken inspiration from Andrew Tridgell’s linux.conf.au talk from a couple of years ago when preparing my setup.

I have, thus far, acquired the following:

Roasting basics
Green beans
  • A surface upon which to set these things — Some timber and screws to make a rough table.
Still to arrive
  • Multimeter — Includes thermocouple, USB connectivity.


Putting it all together has gone reasonably smoothly — the mic stand holds the heat gun (ordering online means it’s hard to judge the strength of the clip, gooseneck or weight of the heatgun before purchase…), I managed to build a sufficiently sturdy table of adequate dimensions, the cooling assembly works as well as I could have hoped (I really wasn’t sure what I was looking for on this front — I purchased pieces that I thought I could combine in an adequate fashion, and got lucky)

The bread machine has an adequate knead setting that keeps the beans moving, though it does pause and change pace and direction during a roast. I was hoping that I could mod it to run the motor continuously and it seems like that might not be too difficult.

This particular bread machine has a temperature sensor that shuts the whole thing down should it get too hot, which happened during my first roast. I relocated the sensor to a more temperate part of the machine.

For the more frugal aspiring coffee roaster, many of these items could have been purchased more cheaply at yard sales or similar. I was motivated by cost and convenience — driving all over the city to save a few $ didn’t strike me as being worthwhile. YMMV. And though we have a vacuum cleaner, I was reluctant to risk heat damage to it.

The multimeter appears to be the same model used by tridge in his setup (and by others if the results of googling the model number are anything to go by), so I’m hoping that it won’t be too much work to get it working with pyRoast and visualize/log roasts. I’ll be able to find out more when it eventually arrives.

The other side of tridge’s setup is the auto-power control and I’m hopeful that the heatgun I’ve chosen will avoid the need for the full custom power control device — I’d like to be able to have pyRoast control the heatgun directly to vary the temperature during the roast. This bit is more of a personal stretch goal.

I’ve successfully roasted beans with this setup but without any kind of temperature feedback, the results seem pretty random. That said,  having freshly roasted beans from my own roaster has already been a wonderful thing!


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