Coffee roaster drum design


New member
Nov 10, 2019
So I'm going to do the typical thing and join to ask a question. It seems like a forum that may be worth investing some time in. I have built several roasters in the last few years, they all had their drawbacks, and I am about to the end of the capabilities of my current one. I think I am going to build a scaled down version of a commercial drum roaster, utilizing a double wall drum with conduction and convection heating. I have searched a lot and can find very little info on how to place the mixing paddles in the drum, and how the beans should move in the drum. The best I can do is find some pictures of drums in videos etc, but very little info on drum design. It seems this is a military grade secret. I would be making a small roaster, 1-3 lbs probably. Does anyone have experience or knowledge on that? Maybe books to recommend? From looking at the large drums it seems the beans travel to one end on the outside of the drum and back to the other end on the inside of the rotating bean mass with the center paddles, but I'm not sure this would work in a small drum. The drum I currently have is the wire mesh one that's all over Ebay, and I have soldered two horizontal paddles in it, and turn it at 60 rpm. It does decentlly well mixing, but it doesn't move the beans side to side any at all, and I am getting a somewhat uneven roast. I am determined to get some direction before I spend money on something that may not work again. Thanks a lot


New member
Dec 4, 2020
I had a friend who started a business with the production of coffee machines, in my opinion, now he has his own factory for the production of various kitchen appliances. I might be able to ask him something like that, but that's not certain. Listen, aren't there people here who know how to invest money?