F e l i x D i a l
f e l i x d i a l at cox dot net
I bought my first popper, the 1200Watt WestBend Poppery2 (WBP2) from an auction on eBay. The total cost of the item was about $15 including shipping and handling. Before this popper even arrived, I won another auction for the 1250Watt WearEver Pumper (WEP2) for about $13 including shipping and handling.
Of course since I made these purchases, I've seen about
10 WBP2s in thrift stores here in San Diego! I've only seen 3 of the WEP2s.
None were priced higher than $5. So I bought 3 WBP2s and all 3 WEP2s as
backups, and all were purchased for less than $15. I also got lucky and
found a 1500Watt WB Poppery1 for $5.50. It was used heavily and required
a good deal of cleaning. I've yet to come across another of the WBP1s and
the 1400Watt WearEver Pumper (WEP1) in a San Diego thrift shop.
Well I selected one of the WBP2s from
my new collection, drilled a small hole through the plastic
top, and with a cooper
thermometer and the two pounds of Kenya Mika and two pounds of the
Organic Bolivian that I bought from Tom and Maria at http://www.sweetmarias.com/,
I began roasting coffee.
After the first two or three roasts,
I disabled the thermostat using a method I found in alt.coffee.
It wasn't long after that that I installed a toggle switch for the heating
element in an attempt to improve my roasts. I drank way too many sour cups
of coffee in the beginning. I guess I was overly ambitious starting out
with the Kenya Mika!
My roasts improved with the toggle
switch, but they were nowhere near what I wanted them to be. I also had
a difficult time getting consistent results from one roast to the next.
I read about people using Variacs
to extend roasting times, but they were pretty expensive and I couldn't
afford to buy one. I also read that dimmers could be used to modify the
amount of heat generated by the heating elements in the poppers. Unfortunately,
dimmers rated higher than 1250Watts usually are priced higher than some
Variacs.
Well thank goodness for eBay. I bought
a Leviton 1500Watt dimmer with a retail price of $150 for $18 (including
$5 s&h). I saw a 2000W dimmer sell on eBay for $2.81 without s&h
at the beginning of this month (Aug 2003 eBay item 2548426289).
After more research on alt.coffee and
web pages on modifying roasters (Cafe
Rosto, FR+,
Popper),
I decided that I might as well modify the poppers to allow full control
of the fans. Note that the WBP2s and WEP2s use two
heat sources. The secondary heat source reduces the voltage from 120V
down to 20-25V and essentially powers the fan motor. Adding the toggle
switch to the popper, as I did above, only toggles the main heat source.
The secondary heat source was always on. Even with the toggle in the off
position, the secondary heat source will still generate enough heat to
keep the popper at about 125°F. If the fan and heat circuits are separated,
the fan motor requires a transformer to reduce the voltage. Turning off
the heat in my setup turns off both primary and secondary heat sources
and the cooling cycle can now reduce the heat from 450°F to 100°F
in about 3 1/2 minutes.
I bought a 600Watt dimmer, a transformer
from Radio Shack (cat number 273-1512), a couple of receptacles, a switch,
and some electrical boxes and connectors. I slapped all of these items
together and placed them all on a plank of wood. The result of all of this
is a control station that allows me full control of the roasting process
by modifying, using two dimmers, both the fan and both the primary and
secondary heaters on a WBP2 and a WEP2. Please see the photos below.
Figure 1: Control Station and WBP2 and WEP2s
All three of the poppers in Figure 1 have been modified. The thermostats have been modified using the method referenced above and the fan motors have been removed from the heating circuit. The WEP2 with the glass hurricane chimney and the WBP2 with the tin can chimney each have two power supply cords. Each popper has one cord that has blue tape (these cords are not visible in Figure 1) and is wired directly to the fan unit within each popper. This blue cord plugs into the receptacle powered by the 600W dimmer (see Figure 2). The second cord has red tape and is wired directly to the primary and secondary heating elements within each popper. This red cord plugs into the receptacle controlled by the 1500W dimmer (see Figure 3). Bad things would happen if I were to accidentally plug the blue cord for the fan into the receptacle dedicated for the heat element cord.
The main switch supplies power to both the fan control
portion and the heat control portion of the controller setup. It is not
in figure 1, but the switch has a 3-prong 15Amp cord used to power the
control station.
The leftmost WEP2 (no On-Off switch
on unit) used to have two cords like the other two poppers. This was actually
the first WEP2 that I modified. However, before I even started roasting
coffee with it, I plugged it into the control station and began playing
with the heat and fan dimmers. Unfortunately, I lowered the fan motor
too far without lowering the heat level, and all of a sudden, the popper
just quit producing heat. I thought I blew out the thermal fuse, but after
opening it up, I found that I blew out the heating coil. The WEP2 with
the glass chimney is its replacement.
Figure 2: Fan Control where the 600W dimmer moderates
the voltage (120V) into the transformer.
Note the timer I use for roasting.
Figure 3: Main Power Switch and 1500W Heat Control. Note the red cord.
I read an article written by Floyd Burton on the SweetMarias roasting list stating that the WBP2s with the label "Poppery II" in white letters versus yellow letters actually have stronger fan motors (Msg 14 of "FrankenRoaster" thread date: Sat Dec 30 18:07:21 2000). Well I have one data point to confirm this claim. The WBP2 that I use (figure 4) has the yellow letters, but the fan and roasting chamber are from a WBP2 with the white letters. An article in alt.coffee recommended drilling holes in the bottom of the roast chamber of a WEP2 to increase air flow and therefore increase roasting capacity (link to article later). Unfortunately, it had the opposite effect in my case with the WBP2. I have not tried this modification with the WEP2s that I own. While I was swapping out the roasting chamber with one of my backups, I broke one of the prongs on the rectifier to the fan motor. So I swapped out the fan motor as well. I guess I got lucky because with the swapped out fan and roasting chamber, from a backup that had the "Poppery II" in white letters, the WBP2 can now easily roast with no stirring 3/4 cups (about 128 grams) of beans. I could probably roast 7/8 cup with stirring but have not tried yet. I tried 3/4 cups in the WEP2, but had to stir not just through the drying stage, but also through first crack. Others have had success modifying their WEP2s to roast 7/8 to 1 cup of green beans. I haven't been so lucky.
Figure 4 is a photo of my primary roaster. Note the tin
chimney and the thermometer and thermocouple "clip holder". The tin chimney
is a vegetable can that I cut a slit into so it would slide into the top
of the WBP2. Before I bought the glass chimney for the WEP2, I used this
same tin chimney in the WEP2. Flipped over, the tin can fits snugly
into the top of the WEP2.
Figure 4 : My Primary Roaster
I've been using the following profile that Mike McKoffee mentions in the SweetMarias roasting list (topic: “Kenya Mika revisited”) with lots of success, format is (minutes, degrees F):
Mike McKoffee Profile
(1, 230°) (2, 300°) (3, 310°) (4, 320°)
(5, 330°) (6, 350°)
(7, 370°) (8, 390°) (9, 410°) (10, 430°)
(11, 440°) (12, 450°)
Update 04 Sep 03: Begin
Mike has informed me that the above profile was intended
for Sumatra and similar coffees and not necessarily for the Kenya Mika.
However, the profile for me yielded results betterthan any of my previous
roasts.
Update 04 Sep 03: End
I modified the profile a bit to allow for a City roast (420°-430°) in 12-13 minutes. I have gotten really good results roasting the Bolivian Organic with this profile.
City Profile
(1, 230°) (2, 300°) (3, 310°) (4, 320°)
(5, 330°) (6, 350°)
(7, 370°) (8, 380°) (9, 390°) (10, 400°)
(11, 410°) (12, 420°) (12.5, 425°) (13, 430°)
Update 19 Nov 03: Begin
The roast profiles I now use are based on the profiles
posted by Jim Schulman to the SweetMarias roasting list (topic: “Variacs
& Roast Profiles” on 27 Aug 03).
Wet Processed Beans
(1, 260°) (2, 270°) (3, 280°) (4, 290°)
(5, 300°) * drying and tanning
(6, 330°) (7, 360°) (8,
390°) * lead up to 1st crack
(9, 400°) (10, 410°) (11, 420°) (12, 430°)
(13, 440°) (12, 450°)
* 1st crack to finish
Dry Processed Beans
(1, 260°) (2, 300°) (3, 330°) (4, 360°)
(5, 390°) * lead up to 1st crack
(6, 400°) (7, 410°) (8,
420°) (9, 430°) (10, 440°) (11, 450°) * 1st
crack to finish
I use these two profiles for all beans that I roast, and
I've been getting excellent results. I don't have enough experience to
have specific profiles for specific bean origins. However, changing
final temperature by as little 5°-10° alone yields noticeable differences.
Update 19 Nov 03: End
In my setup, I found it difficult to do any profile roasting with the cooper thermometer as it is too slow to react to temperature changes. Turning down the heat or speeding up the fan to slow down a roast would often result in really big temperature decreases (sometimes 25°-50° F). Things improved with the use of the Extech 411 Digital Multimeter with thermocouple ($29 on sale from Fry's). I now have a much easier time following a roast profile. However, I still use the cooper thermometer during my roasts. The cooper is very accurate and I use it as check against my Extech readings. I position both the Extech thermocouple and the cooper in the same spot of the roast chamber (figure 5), which is just about the same depth into the roasting chamber as if I had dropped the thermometer through the hole in the plastic top. Actually, figure 5 isn't entirely correct. The beans flow in a counter clockwise direction during the roasting process. The way the thermometer is positioned, it points right into the flow of the beans. While I roast, I actually have the thermometer pointed as much in the center of the chamber as possible or at least in the direction with the flow of the beans. The tin can is positioned properly. It's just that the the thermometer should be pointing either towards the center of the chamber or towards the front-right hand side of the popper, and not the back-right hand side as it is shown in figure 5.
Before I had the thermocouple, for one roast, I positioned
the thermometer lower into the roasting chamber to get it even further
into the bean mass. Unfortunately, the thermometer disrupted the bean flow.
The result was a very uneven roast with lots of scorched coffee beans.
Figure 5: Thermocouple and Almost Accurate Thermometer Position
Figure 6 displays the two WEP2s that I've modified so
far. Again, I blew out the heating coil in the popper on the left. All
that it is good for is blowing nice cool air. If you look at the bottom
of the WEP2 with the glass chimney, you'll see that I've knocked out at
least two of the little plastic squares. I actually removed 8 of these
squares to increase air flow. I don't know if I increased air flow
or not, but I still can't roast without stirring any more than 1/2 cup
of green beans. I will say that it is nice to be able to view the roasting
process through the glass chimney. I have had no luck finding a glass
chimney to fit the WBP2. Note that the WEP2 with the glass chimney is the
model that includes the On-Off switch. In its current modified form,
the On-Off switch serves no function.
Figure 6: WEP2s. Chimney was not cleaned after previous
roasting session.
Also note the lack of "Danger" stickers on these two
poppers.
Figure 7 is a photo of a 1400W WearEver Pumper and the WestBend Poppery. I haven't opened up to see what is inside the Pumper, but from what I've read on-line, the insides are similar to the Poppery.
It would not be too much work to separate the fan motors
from the heating elements in these two poppers and to add an extra cord
in each so that I could use them with my control station. The fans in these
two poppers run on 120V AC, so I would have to add an extra receptacle
to the control station and have the 600W dimmer power this receptacle directly
bypassing the transformer. In fact, I've plugged these two poppers
(not at the same time) into the heater receptacle that's controlled by
the 1500W dimmer in my control station. I was able to simultaneously modify
the fan and the heat using this single dimmer, and in the process, I extended
the roasting profile of popcorn. The result was a very smooth, not
sour, very flavorful, and full bodied batch of roasted corn (grin).
Figure 7: 1400W Pumper and The Poppery
Update 19 Nov 03: I modified both of the poppers in figure 7 and now use them to roast coffee.
click here to view my poppery
modification page
click here to view my coffee
links page
date online: 27 August 2003
last modified: 08 January 2004
