So my good friend Nathan and I decided it would be really fun to build a coffee roaster.
He really wanted to build a PID controller from scratch that ran the roast and I really wanted to build the coffee roaster.
I started studying coffee roasters. During my research, I visited local coffee places that had roasters and studied them, took pictures and thought about how I would design one.
I discovered was that there was primarily two types of roasters out there, barrel roasters that move the beans around a spinning barrel and hot air roasters that shoot hot air into beans and move them around.
I decided to come up with some interesting ways of moving the beans around through hot air.
I thought about a mesh shake table with hot air coming up from below, but thought it might be too unpredictable for an even roast.
Then I thought about a conveyor belt system that would be 3/4 oven and 1/4 glass viewing area so the beans would stay on the belt and you could see them as they went around, kind of like a sushi restaurant. I decided that heating and temporarily cooling the beans wasn’t that efficient even though it looked interesting.
I took the conveyor belt idea and morphed it into a mesh pizza plate concept but then discovered I probably wouldn’t get even heating because the beans in the middle would move through the oven more than the outer ones. Again, uneven roasting.
Then there was a hybrid idea that took the shaker table but removed the shaking and added an agitator and pockets that could open and the roasted beans could fall through.
Another interesting idea would be an auger system that would use pipes and two augers that would move the beans around a pipe system. But what happens when I do a small roast? It probably won’t move the beans the way I want.
Another option is based off an old roaster found in France, it is a simple design but at this point I began to come back around to the barrel design predominantly used in most roasters.
Funny enough I just ended up liking the standard roaster design the most and I wanted to build one out of scavanged parts from kitchen supply stores and scrap yards.
I split up the design into an upper barrel and lower oven section and started the parts search.
And that is ultimately what I am going to build.
