Drum roaster--perforated or closed wall?

[Mark Neuhausen]

I have a grill that is one of the 2% that does not work with the BBQ
roasting drums that have appeared on alt.coffee. It is commercial quality
and has an industrial strength rotisserie that I cannot keep from turning,
fan cooled motor, and a 9/16" octagonal shaft. I was going to try to buy a
modified/redesigned drum, and then decided to just build it myself. With
the perforated stainless steel trash cans now hard to come by, I started
thinking abot perforated or solid drum. Some BBQ roasted coffee that I
tried did have a smoky taste to it which I attributed to the chaff falling
through the drum, into the fire, and burning and producing smoke. With a
closed drum, the chaff would stay in the drum and removal would be during
the cooling cycle in front of (actually on top of) a 20" box fan.

I have chaff that hangs around in my modified PI and have collected some of
it and did not notice it adversely flavoring my coffee. So, my question,
and I accept both opinions and experimental evidence, should my BBQ roaster
have solid or perforated sides?

TIA.

-Mark

[Ed Needham]

I really think the issue of chaff is probably the most significant one in
relation to the solid/perfed question. Of course, the perfed drum will have
less thermal mass than the solid. Of course, the perfed drum will be a bit
more abrasive on the beans (maybe a good thing).
In the long run, I doubt it would make much difference.
I've got two solid stainless drums I intend to turn into coffee roasters.
One is a small one pound size, and one is probably a five pound drum. I
fully expect both to work just fine.
By the way, the large solid drum is part of a bullet trash can I bought at
Target. I may leave the rounded bullet top on the drum and use the spring
assisted flapper door for bean removal. It's not a sure thing yet, but I
think it would work.
--
***********************************************
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com
***********************************************

"Mark Neuhausen" <***@hotmail.com> wrote in message news:***@posting.google.com...
| I have a grill that is one of the 2% that does not work with the BBQ
| roasting drums that have appeared on alt.coffee. It is commercial quality
| and has an industrial strength rotisserie that I cannot keep from turning,
| fan cooled motor, and a 9/16" octagonal shaft. I was going to try to buy a
| modified/redesigned drum, and then decided to just build it myself. With
| the perforated stainless steel trash cans now hard to come by, I started
| thinking abot perforated or solid drum. Some BBQ roasted coffee that I
| tried did have a smoky taste to it which I attributed to the chaff falling
| through the drum, into the fire, and burning and producing smoke. With a
| closed drum, the chaff would stay in the drum and removal would be during
| the cooling cycle in front of (actually on top of) a 20" box fan.
|
| I have chaff that hangs around in my modified PI and have collected some of
| it and did not notice it adversely flavoring my coffee. So, my question,
| and I accept both opinions and experimental evidence, should my BBQ roaster
| have solid or perforated sides?
|
| TIA.
|
| -Mark

[Andy Schecter]

So, my question, and I accept both opinions and experimental
evidence, should my BBQ roaster have solid or perforated sides?

Hi Mark:

I have no experience, just opinion and more questions.

A solid drum will have much slower heat transfer. You'll be heating the beans by
conduction, instead of a combination of convection, conduction and radiation (as
in a perfed drum).

This slower heat transfer might still be fine. Or it might not. I'd speculate
that the rotation speed required to prevent scoarching will be higher with your
solid drum. Does your rotisserie rotate fast enough?

Will your beans roast quickly enough to avoid "baked bean" flavor? (Whatever
that it).

I haven't looked at a whole lot of commercial drum roasters, but they appear to
increase the heat transfer inside their solid drums by blowing heated air
through the drum. This removes the chaff, too, which is captured in a cyclone
separator.

[butch burton]

Post by Mark Neuhausen
I have a grill that is one of the 2% that does not work with the BBQ
roasting drums that have appeared on alt.coffee. It is commercial quality
and has an industrial strength rotisserie that I cannot keep from turning,
fan cooled motor, and a 9/16" octagonal shaft. I was going to try to buy a
modified/redesigned drum, and then decided to just build it myself. With
the perforated stainless steel trash cans now hard to come by, I started
thinking abot perforated or solid drum. Some BBQ roasted coffee that I
tried did have a smoky taste to it which I attributed to the chaff falling
through the drum, into the fire, and burning and producing smoke. With a
closed drum, the chaff would stay in the drum and removal would be during
the cooling cycle in front of (actually on top of) a 20" box fan.
I have chaff that hangs around in my modified PI and have collected some of
it and did not notice it adversely flavoring my coffee. So, my question,
and I accept both opinions and experimental evidence, should my BBQ roaster
have solid or perforated sides?
TIA.
-Mark

Made my drum out of 18 gauge CR steel plate-drilled 3/32" holes IIRC
to be able to roast small beans and get no hangers in the holes. Most
of the chaff comes out the ends where my home made ends and the drum
don't quite meet-but no beans escape or get caught. Very little of
the chaff ends up burning on one of the three burners. The real smoke
production comes from the beans-at least that is my opinion since I do
not have xray vision. Think the real question is does smoke that is
produced by the beans cause any harm or maybe possible benefit if it
stays in the drum.

One advantage to what I call "air drums" -these are very thin walled
drums with lots of holes and little mass - would be if you happen to
roast in colder climates-it will take less time to preheat your drum.
You can also vary the temp faster as there is less mass in the drum.
I went for the more mass approach since it is way easier to fab CR
steel than SS.

Here is an issue I have always wondered about-some drums are fairly
short in length and have a larger diameter while some are longer and
have a smaller diameter-how would that affect roasting-more contact
with the drum vs less. When you get your drum built-buy at least 10#
of a very forgiving bean like Columbian to find your new drum's
roasting sweet spots. Also be prepared for lots of smoke and it
stinks-it infuses your clothing and hide with smoke. A vac is in
order to clean out the grill after each session-let it cool first or
you will melt the vac hose. Also be prepared for burning beans-one
roaster said it was not if but when you have to dispose of a batch of
burning beans-they apparently burn with gusto-said he still has a spot
in his driveway.

Good luck and let us know how the project goes.

[Roger Shoaf]

Post by Mark Neuhausen
I have a grill that is one of the 2% that does not work with the BBQ
roasting drums that have appeared on alt.coffee. It is commercial quality
and has an industrial strength rotisserie that I cannot keep from turning,
fan cooled motor, and a 9/16" octagonal shaft.

Why can't you keep the motor from turning? Removal would seem to take care
of that problem. As far as the 9/16ths shaft size, I assume this is a
problem because the bearing surface is too big for the spit rod. A bushing
would be the answer to that.



I was going to try to buy a

Post by Mark Neuhausen
modified/redesigned drum, and then decided to just build it myself. With
the perforated stainless steel trash cans now hard to come by, I started
thinking abot perforated or solid drum. Some BBQ roasted coffee that I
tried did have a smoky taste to it which I attributed to the chaff falling
through the drum, into the fire, and burning and producing smoke.

I have a perforated drum and the chaff is not what appears to be smoking, it
is coming from the beans.


With a

Post by Mark Neuhausen
closed drum, the chaff would stay in the drum and removal would be during
the cooling cycle in front of (actually on top of) a 20" box fan.
I have chaff that hangs around in my modified PI and have collected some of
it and did not notice it adversely flavoring my coffee. So, my question,
and I accept both opinions and experimental evidence, should my BBQ roaster
have solid or perforated sides?

Small holes and lots of them. I used perf sheet with about a 65% open area
and it works great. Most all of the chaff fall straight through and lands
on an aluminum plate, once in a while a piece will sneak to the flame and
ignite but not a big deal.

I think the best approach would be to modify one of Ron's drums to work, I
made my own from scratch and making one of these is a pain, making 100 would
be a snap as this would justify some nifty jigs to speed the process.

I betcha Ron might even be able to provide you with a larger octagonal shaft
if you needed one also.

[loring]

Post by Mark Neuhausen
I have a grill that is one of the 2% that does not work with the BBQ
roasting drums that have appeared on alt.coffee. It is commercial quality
and has an industrial strength rotisserie that I cannot keep from turning,
fan cooled motor, and a 9/16" octagonal shaft. I was going to try to buy a
modified/redesigned drum, and then decided to just build it myself. With
the perforated stainless steel trash cans now hard to come by, I started
thinking abot perforated or solid drum. Some BBQ roasted coffee that I
tried did have a smoky taste to it which I attributed to the chaff falling
through the drum, into the fire, and burning and producing smoke. With a
closed drum, the chaff would stay in the drum and removal would be during
the cooling cycle in front of (actually on top of) a 20" box fan.
I have chaff that hangs around in my modified PI and have collected some of
it and did not notice it adversely flavoring my coffee. So, my question,
and I accept both opinions and experimental evidence, should my BBQ roaster
have solid or perforated sides?
TIA.

i am still pretty new to gas grill roasting and am not a "craftsman".
i first built a solid drum. having no roasting skills and not being
able to see the coffee made this very difficult. i built a perforated
drum and my skills are starting to grow as far as "pops" and "smell"
goes but i still rely heavily on the visual. i like the perforated
drum.

Loring

Post by Mark Neuhausen
-Mark

[Ed Needham]

I built a small, solid wall stainless drum yesterday afternoon, and roasted a
pound of Peru in it. Major difference is how much heat I needed to get the
beans up to temp. Perfed requires 'much' less heat to push the roast through
it's paces. I roast five pound batches in my perfed drum, and only have the
grill on high to first crack. This small drum, roasting one pound required
the grill temps to be 'much' higher to hit the bean temp marks. I ran
several minutes longer on the roast than I wanted to (a 24 minute roast!)
because I had not anticipated the drastic difference in thermal conductivity,
and I even preheated the solid drum!
My perfed roaster had holes that would allow small beans to fall through or
get stuck in the holes, so I was limited to normal or larger sized beans.
I'm going out now to roast the last half pound of the smallish sized Island
of St. Helena (ISH) stash with my new roaster. I bet it's better than the
Hearthware Precision air roasts I got with that bean. I'll post pics and
results later.
--
***********************************************
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com
***********************************************

"loring" <***@aol.com> wrote in message news:***@posting.google.com...
| i am still pretty new to gas grill roasting and am not a "craftsman".
| i first built a solid drum. having no roasting skills and not being
| able to see the coffee made this very difficult. i built a perforated
| drum and my skills are starting to grow as far as "pops" and "smell"
| goes but i still rely heavily on the visual. i like the perforated
| drum.

[Ed Needham]

Follow up post...
I went to the workshop Friday to build a grill drum that could roast tiny
beans. I opted for a solid wall drum, only large enough to roast a little
less than a pound at a time. I used a stainless restaurant container about 5
inches in diameter and about 7 inches tall. Easily obtained at any
restaurant supply. For the end, I used a stainless steel canning jar funnel.
I installed two stirring vanes that are about 1 1/2 " tall. A flange I had
on hand worked perfectly and the whole thing was finished using a few pieces
of 22 gauge stainless for stirring vanes and an internal strut, a stainless
canister, a flange, a stainless canning jar funnel. Tools used were a drill,
a pop riveter, hand tin snips, a file and a metal, cork backed ruler for
layout and measuring.

The whole thing took about three hours. Here's a picture of the final
result...

Loading Image...

I've roasted two batches in it so far and both tase great. Getting used to
heat settings and establishing patterns for future roasts will be next on my
list. Hey! I wonder if those aged, little Maui Moka beans I still have will
be any good drum roasted? never could roast those BB sized beans in my
drums.

***********************************************
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com
***********************************************

"Ed Needham" <***@NOSPAMhomeroaster.com> wrote in message news:R96yb.156890$***@attbi_s02...
| I built a small, solid wall stainless drum yesterday afternoon, <SNIP>
| I'll post pics andresults later.
| Ed Needham

[Mark Neuhausen]

Thanks for all your comments and responses. I am going to start cheap, want
something that works with all beans, and will likely go with a thin solid
stainless steel can. The end will be open, and I will mount the end brace
at the open end inside the can so that I can have a fixed mount for a
thermocouple to ride in the bean mass as the drum turns. I'm not as worried
about getting the heat into the can, as my grill has an insulated top, 50K
BTUs, plus a 15K BTU infrared rear burner that I have not figured out if it
will help or hurt in the coffee roasting.

-Mark

Post by Mark Neuhausen
I have a grill that is one of the 2% that does not work with the BBQ
roasting drums that have appeared on alt.coffee. It is commercial quality
and has an industrial strength rotisserie that I cannot keep from turning,
fan cooled motor, and a 9/16" octagonal shaft. I was going to try to buy a
modified/redesigned drum, and then decided to just build it myself. With
the perforated stainless steel trash cans now hard to come by, I started
thinking abot perforated or solid drum. Some BBQ roasted coffee that I
tried did have a smoky taste to it which I attributed to the chaff falling
through the drum, into the fire, and burning and producing smoke. With a
closed drum, the chaff would stay in the drum and removal would be during
the cooling cycle in front of (actually on top of) a 20" box fan.
I have chaff that hangs around in my modified PI and have collected some of
it and did not notice it adversely flavoring my coffee. So, my question,
and I accept both opinions and experimental evidence, should my BBQ roaster
have solid or perforated sides?
TIA.
-Mark