Home Made LPG Roaster

[DoubleRis]

I've seen a few home made LPG roasters out there. Perhaps one of the most impressive is this one https://www.youtube.com/watch?v=GP6R-z77yiw.

I'm moving back to the family farm, near Mudgee, very shortly and am keen on trying some home roasting to ensure I always have fresh beans. I have access to a Mig and Tig Welder as well as various other metal working tools and am set on making up something quite solid.

Much like the roaster in the video, I'm thinking of using LPG. I've thought of using BBQ jets, below a rotating drum, driven by an electric motor and a belt.

I'm curious as to whether the drum should be sealed or whether it should have holes in it, like the BBQ coffee roaster drums. Will the beans absorb the scent of the LPG?

Any feedback from home BBQ coffee roaster users would be greatly appreciated.

[Dimal]

That's a damn fine home-made home roaster DR....

What a fantastic effort. As far as roasting drums go, the small commercial jobs I've seen, seem to go for perforated drums to aid air flow and heat transference most likely. Have a look at this video re: the production of small commercial roasters, may give you some food for thought...

Mal.

[DoubleRis]

Great video, Dimal. Nice little Roaster. Might see if I can go take a close look at a roaster to get an idea how the loading hopper and eject door work with the drum. The mesh drum is obviously open at the front but sitting flush against the front metal panel. Tight enough for the beans not to fall out. A matter of mm's. (I assume).

[Aaron]

I built an LPG roaster which i have had running for a few years now. The drum is made from a stainless kitchen canister and its solid. The burner is a segment of a BBQ burner cut to fit the length of the drum. One issue I have with mine is the chaff retention in the drum. My uncle built one on the same principals as mine but with a perforated drum, which allows much more chaff to fall out during the roast. Other than that difference they both work well up to about 750g of beans.
Here's a pic - in this shot I still have an old gas ring as the heat source,

[Bames]

Nice work aaron

Were you roasting on something else before building this? I'm keen to know how something like this compares to a BM/HG set up, as that's what I'm roasting on ATM. It's good and pretty simple but the issue is that I get a little bit of tipping / ashiness that I can't seem to shake. I would be keen to build something like this, but not if the results end up being similar!

[Mono]

Yes, that looks pretty neat, nice job A.

Steve

[Aaron]

I graduated from a pop corn popper to this, which is a pretty big step so its hard to compare. One of the only flaws I found with this was insulating it enough to be able to roast on very cold days. I live in sydney but when i roast outside in the winter it can be hard to get the temp up. The new burner is a big help as it covers more of the drum.
but on windy days i really have to pump the heat in there. It would also be good to find a gas valve with a little finer adjustment, but these are details.
My drum is angled at about 30 degrees to keep the beans from falling out the front. The whole unit - all the aluminium clad bit - hinges forward to dump the beans.
I have been meaning to add an exhaust fan to the horizontal chimney thing, I think it might be good to have some control over airflow, but currently it still roasts fine.

[Harvo]

I have just finished making an LPG drum roaster based on a 50L beer keg with gear motor. I have used a twin ring burner and find the temp control quite good considering the shape doesn't match that of the drum. I haven't picked up any off tastes associated with the LPG. The evenness and repeatability is better than what I had experienced from my coretto. I'll try to upload a video to show off my creation.

[Bames]

Please do Harvo - sounds great!

[Harvo]

I have a video ready to share, but need some kind soul to tell me how to do it! its on an iPad, and is about 16 minutes long (the length of todays roast).

[Bames]

I think you will need to save it onto your computer and then i think load it onto youtube and post a link? Or can you go to Advanced Reply and upload directly?

[aaronpratt]

I'm not an Apple person, but I expect the YouTube app should have the functionality to upload videos on the device. If you log in to it, there should be some option somewhere to upload to your channel.
Interested to see this creation

[Harvo]

http://youtu.be/e5gkqawgy8c is the link - the clip is called BBQ keg coffee roaster. I'm really pleased with it, I'm getting consistent results with load sizes around 1.2kg green.

[Harvo]

As far as getting the heating right, the two ring burner I am using heats the inside of the 50L beer keg well enough to roast 1200g green in 15-16 minutes without any attention paid to insulating the keg body. I would possibly get better heat effectiveness from a fan situated on the extraction outlet, something I haven't tried yet (still have the 5kg roasted beans to get through before I need to roast any more!!). The heat dispersing tray I put inside the keg floor seems to be an important part of the design, as it funnels the heat around the sides of the keg and away from directly under the rotating drum. The temp probe I'm using is situated in the open body of the keg, and tells me I am getting up to 280 deg C at that spot during the roast. Its very pleasing, I may build another!

[MartyMac]

Hi DoubleRis,

I've actually been building a home made LPG roaster myself...well let's call it a DIY roaster, I technically made it at work. But anyway I've used a colander that I modified for the drum. The perforations allow air flow through the drum, which is heated by the gas burners, thus creating a convection oven.

I am in the final stages of the build, so I haven't roasted any beans in it yet. Just have the wiring to complete and I'm in business. I will have to let you know how it goes.

Check some photos on my twitter account. I couldn't get my advanced settings to work on my app, so you might have to copy and paste. Let me know what you think.

Cheers
Marty