BBQ Drum roasters thread

[OkcEspresso]

I just wanted to start a thread from RK or other BBQ drum roasters. While reading the air popper and other commonly found home roasting devices, I mostly cannot relate to the profiles, roast times, etc. I really am under the impression that a huge chasm exists in the attainable flavors profiles between a fluid bed and drum roaster.

I have a little old CharBroil grill that makes maybe 35k BTUs. I drilled a hole right through the middle at about bean height and mounted a K-Type T/C on a piece of steel pipe. I also have a mechanical thermometer sitting on the tin pan I have over the burner (to diffuse the flames). I usually keep the heat around 470 - 490 F with the first snap of 1st crack coming around 10:00 and the first snaps of second coming around 15:30.

Of course, results vary.

Chris

[TimEggers]

Hello Chris,

Your method mirrors my method very much. In fact I have made a site with more information on my set-up:

http://www.angelfire.com/pro2/pan...coffeeroaster.html

Any other drum roasters here?

[mattg]

Tim, you've done a great job of covering the essentials of drum roasting on your site.

The profiles you both have described were what I followed for quite some time. I've recently moved toward a longer roast time and am liking the results. I found that by starting the process off at a lower temperature and running a longer roast, all of the 'green tea' flavours in the aftertaste are removed. Not all beans get the green tea flavours, but just 1 in a blend can influence the flavor significantly. The following profile was worked on by grabbing samples of green and roasted single origin beans from a commercial roaster and profiling until reaching a similar flavour. I haven't managed to get as good a flavour as the commercial samples yet, but am getting closer.

My current profile (using a RK drum and BBQ) consists of:
Start off cold or less than 200F (~100C)
Heat up to 400F (204C) by 5 minutes
Slow down roast slightly to 430F (~220C) by 7 minutes
Further slow down roast to ramp up a few degrees per minute to get to:
440F (225-228C) for 300g beans
455F (235C) for 450-500g beans
473F (245C) for 1000g beans
1st crack should arrive between 15 and 19 minutes
Ramp up another 5-20F to second crack between 4-6 minutes after the start of rolling 1st crack (19 - 25 minutes)

[oofnik]

I was going to make a new thread for mine right before I saw this one.
I'm using an aluminum drum I bought off of eBay that was fabricated to fit a Baby George Foreman rotisserie oven. So far I've been having pretty great results, especially for what I paid. Preheating for at least ten minutes makes a huge difference in quality. I typically roast just a little bit into second crack, taking approx. 22 - 27 mins depending on what beans are in there and how much. Typical load is maybe about 250g, or a little more than a half pound, but I know it can do a full pound.
I got kind of tired of the super slow 3rpm motor (yeah, three), so I took the thing downstairs and started hacking it up. I pulled the motor out, modified its mount, and looked through my endless pile of junk to find something that would work in its place.
Aha!
I came across a Black & Decker electric can opener, powered by one of those AC induction motors turning a gear reduction. It spins at maybe 40rpm - I haven't measured it but it takes a bit longer than 1 sec/rev, so it's around there. So, being the twisted mad reverse engineer I am, I whipped out my Dremel and went to work.
This is what emerged:

[gvideo]http://video.google.com/videoplay?docid=-5133515611141398831[/gvideo]

I'll get around to making a proper mount for the motor assembly, but for now, this'll do.

[Kaffee Bitte]

Nice thread gents. I like the digs Tim. Just a few questions since I am seriously considering going this route over the summer. What thermometer should I get to measure the bean temp? I noticed Tim's on his web page but it wasn't clear just how it worked (at least not to me.) As far as motors go, are there other motors out there with enough oomph besides the RK motor? (probably end up going that route anyway though) Finally what would be the minimum BTU's a grill would need to pump out, provided I wanted to attempt using this monster year round? Just to clarify, I live in Montana, and it often gets below 10 deg. F. in the winter. Though there are also many weeks where the temp is 32 or above.
I already have an option for the drum itself. My father has a friend who does metal work as a hobby, so he is going to make me a drum to the specifications I provide. Well maybe just a couple more questions. What thickness for the perforated steel? How far into the bean mass should the mixing veins stick? The guy who is going to do this for me is looking at various designs online but if you all have some good input it would help out a lot. Can't think of anything else at the moment. Thanks