Too Much Coffee
Roasting - Equipment and Techniques - BeanBrowner Mark I Prototype
liyang - Jul 15, 2009 - 11:57 AM
Post subject: BeanBrowner Mark I Prototype
Here's the link if you want to twit: http://img.ly/1HD
Total cost, not including time and tools and instruments: £20. The (de-varnished) Illy tin was another £4 I think.
That is all for now. Got to get to work. =)
darrensandford - Jul 15, 2009 - 02:41 PM
Post subject: RE: BeanBrowner Mark I Prototype
Haha! That's an awesome looking device, well done! Will be interested to see what it produces.
triptogenetica - Jul 15, 2009 - 05:57 PM
Post subject: RE: BeanBrowner Mark I Prototype
Ah, that's the mini oven I've been using for home roasting!
(I found that a popper gives me a more even roast, but in smaller volumes. A baking tray, occasionally stirred, in that oven gives a larger amount, but not as even. Hopefully the rotisserie drum should improve on this)...
How did you get the spindle mounted in the oven - have you added bearings of some sort? (I thought about doing this to ours, but we also use it for all oven cooking that doesn't need the big oven. It's very mini, but does a good job. So my GF would be unhappy if I made this out of it). 
CakeBoy - Jul 15, 2009 - 06:42 PM
Post subject: RE: BeanBrowner Mark I Prototype
Nice one Liyang How are the roasts?
liyang - Jul 15, 2009 - 11:36 PM
Post subject: Re: BeanBrowner Mark I Prototype
CakeBoy wrote:
Nice one Liyang
How are the roasts?
Well, the one on the left is Steve's Machacamarca; the one in the middle is mine, roasted at what I *thought* was a flat 250ºC profile, but may actually have been closer to 270ºC†; and the one at the right is my Colombia La Manuela at what I thought was 230ºC — I was trying to drag out the roast — but probably closer to 250ºC†. (Don't have Steve's to compare, sorry.)
The Columbian came out somewhat under-roasted — was getting dark and I couldn't see very well — but the colour is very even. I think I stopped it half-way between first and second crack; I may have been a tad too conservative here as I've not quite figured out where the line is drawn between the first and second…
I suspect the mild unevenness of my Machacamarca is due to the ridiculously high temperatures. They do look slightly browner than Steve's, and I'm not sure I heard the first crack, which confused me. It was light enough at that point for me to see that I ought to stop the roast, however.
Σ:3
/Liyang
† Bad placement of the thermocouple probe on my part.
liyang - Jul 16, 2009 - 12:47 AM
Post subject: Re: BeanBrowner Mark I Prototype
triptogenetica wrote:
Ah, that's the mini oven I've been using for home roasting!
Ah, I've been reading your Wiki entry!
triptogenetica wrote:
A baking tray, occasionally stirred, in that oven gives a larger amount, but not as even.
I never figured out how you could stir it without a significant temperature drop. D: That's what stirred me into concocting this harebrained idea, so it wasn't a bad thing…
The BeanBrowner Mk I has comfortably done 125g so far. Could perhaps go up to just under 200g… further tests needed; the Illy tin is rated at 250g — I'd have used a larger vessel had I found something suitable. Burning all the varnish off the tin with a crème brûlée torch nearly melted the front of mine…
For a steel tin, it's next to impossible to drill clean, circular holes on the side (already ruined another Illy tin), so I made four 45º cuts — with abrasive cutting discs‡ on a Dremel knock-off — in a pretty snowflake pattern instead. Use a few‡ rotary wire brushes to clean the cuts from the inside and out.
triptogenetica wrote:
How did you get the spindle mounted in the oven […]?
I took out the thermal cut-out fuse from the control side of the oven, drilled a hole through both the metal tab and the oven wall on the right. (Use a HSS bit for this. If you don't have a centre punch, abuse a sharp wood screw with a hammer to mark the spot.) On the left I just drilled a hole in the same position.
The spindles are actually 100mm M6† carriage bolts from Wilkinsons, with one on the right fixed in place by squeezing a nut in between the tab and the oven wall on the outside. Another pair of nuts tightened against each other act as a stop for the drum. There's a metal tube† running through the middle of the (no longer recognisably Illy) drum, fixed in place at the open end by thick (stripped) gardening wire, illustrated in the photo below. (X cuts along the ridges on the neck of the tin to make holes for the garden wire.) At the closed end I intended to solder the tube to the tin, but haven't done so yet — there's probably no need.
For the cap, drill a centred hole, and clamp it tight between two oversized M6 washers, in turn in between a pair of nuts. Leave an inch of the bolt showing, to plug in to the end of the tube above held in position by garden wire. In between the end of the bolt and nut, put on another section of steel tubing — crimp one end slightly so it won't slide about — to give a smooth surface that can rotate freely in the hole you've drilled on the left oven wall. Maybe add a few dabs of silicone grease, though I haven't needed it myself yet — coffee oil seems to work. At the cap end of the bolt, you can fix a long thin piece of wood, to use as a handle… (not in my first, or any of my photos, yet.) Note if you are actually building this, it may be less frustrating to read this paragraph backwards.
Oh and you'll want to stuff some tin foil around the inside of the tin lid, firstly to stop beans from getting jammed in between the tin and its lid — there'll be a gap since you'll have removed the plastic parts — and subsequently expanding, making the two almost impossible to separate at high temperatures, and secondly to provide a little extra friction so the drum would rotate.
triptogenetica wrote:
I thought about doing this to ours, but we also use it for all oven cooking that doesn't need the big oven.
It's £13 from Argos at the minute. You have no excuse. Other than the lack of time. This took me about two days — interspersed with bits of PhD work — to put together.
Apologies for the brain-dump. I figure I ought to get all the details down while they're still fresh.
later,
/Liyang
† The tube is actually the inner rod of Wilko's 60cm to 100cm telescopic window net rod, stripped of its plastic covering. I bought the M6 nuts and bolts to match. You may want some other size.
‡ I went through half a dozen abrasive discs, and two wire brushes. Haven't quite factored in the cost of those.
liyang - Jul 16, 2009 - 12:54 AM
Post subject: Re: BeanBrowner Mark I Prototype
liyang wrote:
I suspect the mild unevenness of my Machacamarca is due to the ridiculously high temperatures. They do look slightly browner than Steve's, and I'm not sure I heard the first crack, which confused me. It was light enough at that point for me to see that I ought to stop the roast, however.
I should point out that during my taste test, the two were very similar. I'd struggle to tell the difference, but then my palate isn't as developed as a professional cupper, and I've probably killed most of my taste buds by being fed — what would be to most British people — uncomfortably hot (as in, spicy) food since birth.
GreenBean - Jul 18, 2009 - 10:18 AM
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Very impressive Liyang.
triptogenetica - Jul 18, 2009 - 12:19 PM
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Liyang, thanks for the write-up! (I imagine it's also a welcome break from writing up the PhD). It's good to see someone improving that oven - maybe we should get this added to the wiki...
As for stirring - I was simply opening the door as little as possible, reaching in with a fish-slice, and giving everything a good stir. Not ideal, but you get quite deft at at after some practice.
For an excuse not to do this - I gave in and now have one of Joe Behm's exciting roasters. Otherwise this would be my next project. As it is, though, i think my flatmates will quite like the smoke suppression stuff Behm has invented 
Joris - Mar 05, 2010 - 10:59 AM
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Nice DIY project
qwerty69 - Mar 05, 2010 - 08:40 PM
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What a fantastic use for a tin of Illy, tell me you didn't make coffee with the beans though 