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portable "concrete mixer" roaster

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  • portable "concrete mixer" roaster

    Ive been working on my design for my first roaster so I thought Id ask a few opinions before I kicked into building it. My design has been influenced by a few needs

    -complete lack of cash ;D
    -need for portability & ability to run off 12v supply (ie camper van socket)

    I like the idea of a rotisserie style roaster, but they all seem bbq based. But making a drum seemed like a pain & having to empty it while it was hot is a bit of a downside
    So I though why not a concrete-mixer style rotisserie
    So heres my sketch for what Im planning, I think materials needed will be

    -large stainless steel billy courtesy of ozzie disposals
    -windscreen wiper motor from a very dodgey motor-wrecker
    -old camp stove that I have hundreds of spare canisters for
    -a few bits of metal and a pop-riveter
    -bolts & nuts as needed

    So heres a sketch of the plan

    Im thinking it might be able to roast about 500g of coffee at a time, depending on the size of the billy.
    So Id run the roast then just turn off the stove and hit the beans with a 12v fan
    If it struggled to get up to temp I could also run it with the lid on the billy.

    My only concerns are that the billy isnt perforated & probably should be.

    Just wondering if anyone has tried anything like this? Any suggestions/criticism is welcome before I start the build.
    Any alternatives I could use instead of the billy would be welcome too

  • #2
    Re: portable "concrete mixer" roaster

    Looks very interesting
    Im thinking you could maybe use a HG instead of a gas stove, it may be easier to do little alterations to it. If you used the gas stove and have holes in the drum maybe the beans just get burnt on the outside. If you used a HG the holes could let chaff out.
    But if you used a HG then you wouldnt need holes probably since the air blown in would just shoot the chaff out.



    • #3
      Re: portable "concrete mixer" roaster

      Dont know how you would go with a HG on 12v but I would give the gas stove a miss.

      I used the same principle with the bbq for a while and had a lot of problems with the outside beans getting too hot.

      Arrived a a vane shape that was more like a cork screw with some success, it forced the beans towards the front which made dumping easier as well.

      The Coretto is a great alternative, you can also set it up in the toilet block of most municipal camp grounds when you are on the road.


      • #4
        Re: portable "concrete mixer" roaster

        you could simply roast in a largish ( wide, but not too deep) SS pot, or even a small wok which sits on your camping stove and use a whisk to agitate; it may be old fashioned but it does work and the advantage is that you can see the beans and manipulate the heat according to the roast level...
        roasted that way, a batch of about 300gm or 400 gm will roast better than a smaller batch, because of the heat distribution/retention.

        somehow i dont think that the various councils would be too pleased with having to clean chaff out of their amenities blocks
        i have Corretto-roasted in our own (motorhome) bathroom when the weather was too bad to do it outside and there is still chaff hanging in the curtain and behind the mirror! ;D ;D

        Good Luck,



        • #5
          Re: portable "concrete mixer" roaster

          For some reason, everytime I see something perforated or made with mesh I think about coffee roasting.
          The following odds and ends have caught my eye lately:

          Saw this metal light shade [model FA12021 or 12019] only $30 at Bunnings its very strong and could well do the job....see pic at link:

          Have thought about joining [hinging] 2 of those SS conical shaped colanders together.

          Howards Storage Solutions and probably Officeworks have chrome mesh waste baskets.

          Robusto seems to be the resident CS BBQ Drum roaster, give him a PM

          Originally posted by Lizzi link=1195024688/0#3 date=1195074373
          i have Corretto-roasted in our own (motorhome) bathroom when the weather was too bad to do it outside and there is still chaff hanging in the curtain and behind the mirror! L
          Lizzi.........thats true CS dedication!


          • #6
            Re: portable "concrete mixer" roaster


            2nd post down is a contraption I made thats very simlar, you really need a way to stir the beans back to teh top to keep the roast even and it needs to be very strong to support the weight

            perhaps for 12v powered you could use the wiper motor to run a paddle like a bread maker and use some type of blowtorch as a heat source