HomeRoast Digest

Topic: more on Pumper roasting (14 msgs / 458 lines)
1) From: peter zulkowski
Well, my wife had to go to Walmart anyway, and of course I had to go to 
the thrift shops. In deference to roasting larger quantities, I picked 
up a larger cooling fan (10 ") for 2.50. It puts out lots of air, but 
just blows the chaff away and stirs the beans gently.
So I got my 5 gallon plastic pail with a lid. The lids did not fir the 
half size very well, and they cost 50 cents more besides. (Bucket 2.50, 
lid .97)
Had dinner and used my X acto knife to cut out a hole for the Pumper in 
the lid of the bucket and an inlet in the side for the Stinger Vacuum 
from Home Depot for under $30.00. Thanks to the tip from this list :)
I did not want to fool with the new flexible thermocouple so just 
inserted my Cooper into the side of the aluminum chimney like when I do 
only 150 gr. This batch was 250 gr.
First I dumped the 250 gr. into the roast chamber, and it filled it well 
above the slotted aluminum chamber. I put on the extension chamber (10" 
aluminum flashing, about the same diameter as the chamber, it is a press 
fit) and turned on the Pumper air. That did not move the beans so I 
cranked up the voltage on the Stinger. This did not blow beans all over 
the porch as I thought it might. I really did not need the Variac on it 
at all except to boost the power to it. It did ruffle the beans some, 
but when I turned on the heater power I found I got better results when 
I tilted the whole thing, and kept it tilted for the first 3 minutes or 
so. I tried cutting back on the Stinger air, but that dropped bean 
agitation such that I thought beans would burn. After about 6 Minutes 
first crack was in full swing, and I did cut back the vacuum air a bit 
to keep the beans moving smoothly.
During this time the temperature on the thermometer never got above 300 
F. Definitely need to experiment with placement, the probe by now was 
about in the middle of the mass.
By about 11 minutes it was definitely into 2nd crack.. lots of smoke and 
noise from the beans, and they were starting to jump out of the top of 
the chamber from sheer volume! So I added my glass chimney to the top of 
this, just to keep the beans from flying onto the porch. At about 12 
minutes I cut the heat power, and let the blowers cool it for about 30 
seconds before dumping into my cooling basket over the 'new' fan.
What did I learn from this.... wellll..
One should use duct tape around the top of the Pumper where the top 
joins the side. Lots of hot air comes out there during 'supercharging'.
1250 watts of Popcorn Pumper will definitely roast  250 gr. of coffee 
evenly into first crack and on and on, if you boost the air flow; and in 
a reasonable amount of time also :)
Adding additional air flow is very noisy with a cheap shop vac ;)
If I really want to roast 1/2 lb at a time I need a bigger roasting 
chamber :)
With so many beans I have no idea what their temperature is, but the 
coffee comes out good by using the old sight, sound and smell method.
More about the setup.
I roast on the back porch, and everything is connected to one electrical 
outlet, which I suspect is run off the same outlet with the ground fault 
in the bathroom that runs all the other outside connections.
Into this outlet I have a 16 gauge 25 foot extension cord, and a 3 
outlet adapter on the end of it. (Talk about a large resistor)
Into this I have plugged the heater Variac, the Pumper fan control box, 
and the cooling fan that I hold the basket over at the end. The Stinger 
Variac was plugged into the same wall in the upper outlet of the two.
All this because I could not make up my mind between a french roast and 
an alpenrost.
Not sure if I have spent enough that I could have bought a Hot top.... 
Close ......
This is surely more fun though :)
Still roasting in the dark here in LHC, where the wind sometimes dies 
down after sundown.

2) From: Johnny Kent
At 09:23 PM 1/3/2004 -0700, peter zulkowski  wrote:
That's surprizing. There must be an air leak somewhere.
My stinger will loft 12 oz greens into a fountain stream 12 inches above
the roast chamber on full power without a variac.
I silenced mine some with an  overcoat of R13 insulation.
Anyway it looks like you are having a lot of fun.

3) From: peter zulkowski
This is a multi-part message in MIME format.
Hi Johnny,
thanks for the reply. What do you use for a roaster?
Yes, I do have a few air leaks, and need to get out the duct tape. No 
real seal anywhere (did this in the dark kinda).  When I seal it better 
I will report the results.
However what is really bothering me is the temperature thing.
Do you think it is possible that the beans are only getting to 300F and 
still getting into second crack?
Do you measure the temp while roasting? If so, where do you take your 
Yes, I am still a newbie at this, every day I learn more and more.
Thanks for the tip on the insulation :)
Still having fun roasting here in 48F LHC
Johnny Kent wrote:

4) From: Ron Kyle
snip from Peter Z's Post:
At 300 degrees, coffee beans would not even get to first crack.
First crack on a regular metal probe thermometer, stuck in the mass of
roasting beans should read between 375 to 400 degrees for first crack and
anywhere between 435 and 455 for 2nd crack. These are the readings I used to
get when I was roasting with a hot air roaster.
Ron Kyle

5) From: Ed Needham
Just had an interesting idea, since Peter mentioned a 5 gallon bucket.  How
about setting the air roasters 'inside' the bucket to roast in cold days?
You could use the lid or other device to close off part of the top of the
bucket to allow more or less heat buildup inside.  Chaff would be a problem
with the popper roasters, and might get recirculated into the roaster unless
a chaff collector could be placed on top of the roaster.  HWP's, FR's and
other air roasters would be fine.
Might do better than a box, and when done, throw everything in the bucket and
store until the next time.
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com

6) From: Gene Smith
I tested my Aromaroast this way and the temperatures really jumped.
Problem: If you want to stop the extra heating, or deal with the end of the
roast, you will find it awkward to reach into the bucket to cope with hot
everything.  The simple solution: cut the bottom out of the bucket and lower
it around the roaster instead of putting the roaster inside it.  You get the
same effect and it is instantly adjustable - just lift the bucket off.  You
do lose the handy storage container, however.
Gene Smith
riding the wild learning curve in Houston

7) From: Ed Needham
...or screw the roaster to the lid, and lower the bucket over the roaster.
Cut half of the bucket bottom away, and bold on another piece of plastic
which can be rotated to open or close the opening.  Timers and thermometers
can be attached to the bucket for easy access.  When finished roasting, the
lid and roaster are inverted into the 'storage bucket', and stashed away.
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com

8) From: Gene Smith
My oh my, you folks *does* like to complicate things, doesn't you?  Okay, I
admit it, I do, too...but in this instance it doesn't seem necessary.  I
cannot speak for the popper crowd, but my anemic little Aromaroast tops out
at about 430F empty in 6 minutes (with the simple mod. that allows the
baffle to close all the way) and when I set it down in the bucket it hit
500F in 5 minutes - at which point I shut it off.
That was with no restriction whatsoever to the top of the bucket - just
allowing the sides of the bucket to recirculate some of the hot air coming
out the top of the Aromaroast to the air intake in the bottom.  I don't
think the walls of the bucket even needed to be that high - it certainly
didn't need a top on it unless you wanted to melt something, or set it on
Now, considering that when I finally did a roast with real beans my slightly
modified Aromaroast hit 450F by 8 minutes and 460F long before the end of
the roast, the only thing I would need the bucket for would be to kick the
temp higher/faster than I am already getting...OR...to kick up the heat
while using the full airflow position in order to roast more beans.
At full airflow (empty) the Aromaroast barely crosses 300F...305F was the
most I saw with no beans in it.  I suspect with the help of the bucket, I
can get roasting temperatures while still moving the beans adequately at a
larger bean weight/volume.  But I would like to wait until I can rig a
chimney to try it.  That's why I've been asking about the size of the
Freshroast glass roasting chamber - I want a see-through chimney, not a tin
can, so I can watch the roasting process without taking the chaff collecter
off the top of the Aromaroast - and losing a lot of hard-won heat in the
I think the Aromaroast still has potential - even without the more radical
Gene Smith
riding the wild learning curve in Houston

9) From: Ron Kyle
Snip from Gene Smith
Freshroast glass roasting chamber -
Gene It measures 2.5" dia. by 4.25 high. I have one that has a slight crack
in it, but it should do fine for a chimney. You can have it if you want it.

10) From: Ed Needham
Gene...the bucket suggestion was pretty much for people who 'must' roast
outside on cold days.  Even the best popper/roaster has a hard time keeping
temps high enough if the temps are down near freezing.  Thus, the bucket,
which replaces the cardboard box, which I would imagine has been frustrating
for some to use if the wind kicks up a bit.
sorry I didn't make that more clear.
Ed Needham
To Absurdity and Beyond!
homeroaster ... d.o.t ... com

11) From: Gene Smith
My bad, too, Ed, as I suspected that might be what you were referring to.
In Houston it is necessary to remind oneself from time to time that it
*does* get cold in other places.  I would still run a temp check with an
open bucket - even outdoors in the cold - just to see what happened
(assuming the availability of a temp. measuring device)...I was surprised at
how quickly the recycled hot air kicked the temperature up - even though the
top of the bucket was completely open.
I loved the idea of inverting the bucket and creating an adjustable baffle
in the bottom, by the way.  Too cool!  I thought about doing that by cutting
the bottom off another bucket - since they stack - and cutting half out of
each.  Slip the cutoff over the whole bucket bottom and get a baffle that
adjusts from 0 to 50% opening just by twisting.  Of course, one of the
advantages of using the bucket the right way up - a handle to quickly grab
if things go really wrong - is compromised by inverting it.
Gene Smith
riding the wild learning curve in Houston

12) From: Gene Smith
Is the 2.5" an inner diameter or an outer diameter, Ron?  In either case,
yes, thank you very much, I would love to play with it and see if I can make
it work.
Gene Smith
riding the wild learning curve in Houston

13) From: Ken Mary
Keep up the work, there are very few of us Aromaroast users left. Do not
worry about losing heat while lifting the trap to check on the beans. The
chamber design seems to give me cleaner roast flavors near second crack when
compared with poppers.

14) From: Michael Walls
I think a pasta pot might work.Find one that has
enough space under the stainer basket to fit a
stripped down popper. Cut a whole in the bottom of the
strainer to fit around the popper then line the
stainer with metal screen. I believe the Rosto would
be cheaper and better in the long run. Since I
bypassed the thermostat and thermo fuse and added a
dimmer on mine it has been working perfectly for small
batches. I took the bowl off because it would not get
hot enough to roast when the temp is too cold outside.
Mike Walls,
 From: "Gene Smith" 
Subject: Re: +more on Pumper roasting
Date: Sun, 4 Jan 2004 14:21:21 -0600
Reply-To: homeroast
a 5 gallon 
to roast in cold 
part of the top of 
Chaff would be a
into the roaster
roaster.  HWP's, FR's 
everything in the 

HomeRoast Digest