Introducing myself and my roaster. Hi from CO, USA - Page 2

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
Capuchin Monk

#11: Post by Capuchin Monk »

I notice that you own or have access to some serious metal tools. Are you completely set on fluid bed air roaster or have you thought about building a drum roaster as well?

Erichimedes (original poster)
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#12: Post by Erichimedes (original poster) replying to Capuchin Monk »

I have, pretty seriously in the past. I always had a bit of an inferiority complex using an air roaster, since I would see it written over and over again that serious roasters use drums. But with roasts getting lighter and faster, and hybrid roasters like IMF and Loring machines becoming popular, I feel somewhat vindicated in sticking with air. My roasts have always been better than anything I've ever had out of a commercial drum roaster, but I've never had the opportunity to actually compare side to side with fresh, well roasted drum coffee so I really just don't know.

What it came down to for me was that a drum roaster is significantly more complex to make than an air roaster, and they also take up more room. And if I'm going to make a drum roaster, I want it done right with helical vanes, a real cooling tray, and full control over airflow, heat and drum speed. I actually made the drum already for a 2.5lb roaster, and when I got to the next step I realized the scale of what I was taking on, and put that project on hold. The drum is just sitting on my shelf. It really comes down to scale. For commercial roasting, an air roaster like mine makes absolutely no sense at all, but one could also argue that on the hobby scale, a drum roaster is pretty overly complex for doing the job of roasting coffee. Don't get me wrong, just because it's overly complex, doesn't mean one shouldn't roast in a drum, it just means that for me, making the thing from scratch, it felt like too much work.

That said, I'm really, really interested in hybrid style roasters like IMF and Loring drums. It would be quite easy to make a drum attachment that uses my roaster as the heat/control source, so I would like to do that someday in the future. I might make it so that the solid drum I already made fits, but also can use a perforated drum so I can switch them out. I'm not actually convinced that a hybrid perforated drum air roaster would make coffee that is significantly different in any way than my fluid bed roaster makes, but it would be fun to find out. I think for commercial roasting it just comes down to scale. My fluid bed is slightly less efficient in it's use of heat and airflow, but at the amount of coffee I roast per year it's completely negligible. For commercial roasting, totally different story of course.

Sorry, another long answer, but your question has plagued me in one way or another for years :lol:

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#13: Post by Brewzologist »

Another option would be to pick up a used drum roaster and mod it to take air input (vs burner) to create a hybrid roaster.

For example, I've pondered the idea of modding my Huky to do this by adding a sealed plate on the bottom except for air input from the bottom/back of the plate. I could do this where it's completely reversible in case I wanted to go back to a conventional drum. I've already implemented RPM control of the drum and exhaust fan control which I could leverage in the hybrid roaster. Add an inlet temp probe to my existing Phidgets and of course the heat gun assembly and maybe I'm mostly done?!

FYI: I lived in Durango from 2000-2012. Great area.

Erichimedes (original poster)
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#14: Post by Erichimedes (original poster) replying to Brewzologist »

Sorry for the slow reply here, that's awesome you lived in Durango! It's a good spot, it's getting pretty big these days but we still like it.

Yes, I think a lot of the smaller drum roasters like the Huky could be pretty easily converted to a convection specific design. They already sell the perforated drum (at least for the Huky, not sure about the others like the Quest M3?) so all you need to do is add the heat source like you described. Let us know how it goes if you try it!