HomeRoast Digest


Topic: IRoast 2 Tip Sheet (30 msgs / 795 lines)
1) From: Christopher Navarro
I'm fairly new to home roasting ( 6 months in using an IRoast 2) and I have
a question for those who are more knowledgeable than I about the IRoast 2.
I've tried following the tip sheet where I set three stages:
340 deg F for 2 min
390 deg F for 3 min
450 deg F for 4 min to 6 min
The guide says 4 to 6 minutes in the last stage at 450 will give roughly a
City to FC/FC+.  At the about 3 minutes into stage 3 (450 deg F), using
"Brazil Daterra Farms Yellow Bourbon" from sweetmarias, the beans had a
shiny/glossy look them which seemed to be somewhere between light vienna and
Full French.  I have a dryer hose attached to the top to vent smoke so this
probably makes it more difficult for the roaster to vent the heat as
efficiently as without the hose obstructing it.  I'm also roasting in the
basement so the ambient temperature is probably about 60 degrees F.  The
IRoast puts off so much noise that I am probably going to add a thermocouple
soon so I can watch the temperature more closely in the chamber.  Until
then, does anyone have a similar setup that can offer an adjustment to the
suggested temperature profile?  I haven't measured the voltage of the outlet
so that too could be a reason that my roasts seem to progress faster than
they should.
Thanks,
Chris
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2) From: Seth Grandeau
Chris,
The IR2 is not very accurate.  I've done roasts of the same bean, same day,
same weight, and been off by over a minute in the two roasts.  Your best bet
is to watch it like a hawk.  Listen for the cracks (I found Noise Cancelling
headphones to help) and watch the color closely.  I used profiles that had
the last leg go up to the max and I would manually end the roast when it
reached my desired level.
Good luck!
-Seth
On 1/23/09, Christopher Navarro  wrote:
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3) From: Allon Stern
The IR2 *CAN* be more accurate if you give it adequate time to cool  
down between roasts - like only 1 roast a day.
However it is still wildly inaccurate. The internal temperature  
measurement is a joke.
Get a thermocouple and snake it into the bean mass so you can watch  
it more closely. Then adjust your profile accordingly.
I have added a variable speed exhaust fan to allow even greater  
control - the thing that sucks about the iRoast is how little control  
it gives you once you start a roast. Adding an externally controlled  
fan helps a lot.
Your profile, btw, ramps up to first crack, then pours on the heat.  
After first crack, the last thing you want is MORE heat, unless you  
want to race to 2nd crack. I'd suggest maybe a burst of heat, maybe  
450F for 1.5 minutes, then back down to 390F for as long as the  
roaster will let you program (up to 15 minutes). Then run the profile  
and hit the stop button when you've achieved the level of roast you  
want.
Also note that dry processed coffees will run faster/hotter because  
the chaff blocks the screen, and the profile may not work as well for  
decaf or extremely low chaff coffees.
I've all but given up iRoasting, preferring to use a heat gun instead.
-
allon
On Jan 26, 2009, at 12:05 PM, Seth Grandeau wrote:
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4) From: Christopher Navarro
Seth,
I have a pair of noise canceling headphones so I think I'll give your
suggestion a try.  Thanks for the tip.
-Chris
On Mon, Jan 26, 2009 at 11:05 AM, Seth Grandeau  wrote:
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5) From: Douglas Hoople
Yes, you must stand ready at the end to push the 'Cool' button. Most of the
roasts in this profile wind up anywhere from Vienna to near-charcoal.
So you have to choose when to stop the roast. You'll never be able to tweak
it to stop on autopilot, nor should you really want to.
You'll find the thermocouple to be a huge help, and learning to identify the
phases of the cracks is critical, even if it is difficult because of all the
noise. You'll find that the thermocouple alone won't always deliver the
results you want. Following the cracks is really the key with the iR2.
I just learned all this over the past couple of weeks, and my coffees have
improved by an order of magnitude.
Doug
On Fri, Jan 23, 2009 at 11:20 AM, Christopher Navarro
wrote:
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6) From: james McDougal
Noise cancelling ear phones - what a great idea. Should take out the noise
from the hood on full blast and the noise from the behmor too! Can't wait to
try it.
Mac
On Mon, Jan 26, 2009 at 12:47 PM, Christopher Navarro
wrote:
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7) From: Douglas Hoople
But don't they also cancel the sound of the cracks?
On Tue, Jan 27, 2009 at 4:08 AM, james McDougal wrote:
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8) From: Seth Grandeau
Active noise cancelling removes the constant droning or buzzing noises.
Think airplane engines or IR2 fans.  Sharp sounds, like voices or coffee
cracks come through nicely.  Passive noise cancelling (like shooters ear
muffs) cut out everything.
On 1/27/09, Douglas Hoople  wrote:
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9) From: Allon Stern
On Jan 27, 2009, at 12:38 PM, Seth Grandeau wrote:
<Snip>
I've seen shooting muffs which have microphones on the outside and  
speakers on the inside, so you can hear what's around you, but they  
have a fast-response audio compressor, so it clamps down loud noises  
fast. It's really odd to get used to when using a nailer or shooting  
- you hear everything fine until there's a loud noise, when  
everything cuts out for a second (it's got a slow release).
Useless for roasting, though :)
-
allon
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10) From: Dave Huddle
What brand, model of noise canceling headphones do you suggest?
It's a bit hard to hear cracks from the Behmor when the exhaust hood
is running in my roasting/laundry room.
Dave
Westerville, OH
On Mon, Jan 26, 2009 at 12:47 PM, Christopher Navarro
 wrote:
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11) From: Douglas Hoople
And to think I've been able to put off buying a set of these until now!
Just wait 'til I tell my wife that the perfect cup of coffee requires a set
of noise-cancelling headphones! :)
Doug
On Tue, Jan 27, 2009 at 9:38 AM, Seth Grandeau  wrote:
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12) From: Seth Grandeau
I had a very cheap pair of Sony headphones that are probably 4 or 5 years
old now.  I'm sure there is much better on the market.  Mine did not
eliminate the sound of the IR2, but it cut it down and made the cracks
easier to hear.  I have not tried it with the Behmor, as I do not use a
range hood and can hear the cracks fairly easily.
On 1/27/09, Dave Huddle <137trimethyl26dioxopurine> wrote:
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13) From: james McDougal
I tried the noise cancelling earphones this morning with 4 oz of "Donkey"
espresso blend in the Behmor. I have a Targus pair that is several years old
but I think they might have cost a couple of hundred bucks. They diminished
the noise from the range hood, the afterburner and the cooling fan - but
they also muted the first cracks. I pulled them off to finish the roast to
be sure I could tell 1C from 2C. So I guess that the noise cancelling
earphones are not going to be a regular part of my roasting routine.
Hope everyone is having a great day - It's a snow day here in Dayton and my
University, the AF base and all the schools are closed.
Mac
On Tue, Jan 27, 2009 at 3:59 PM, Seth Grandeau  wrote:
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14) From: Mike Koenig
Try listening for the cracks from ~ 5-10 feet back.  When I was using
an iRoast, it seemed I was better able to tune out the drone of the
fan, and hear the cracks from a distance.  I think the fan didn't
"overload" my hearing at that range, and the cracks come through
clearer.
--mike
On Wed, Jan 28, 2009 at 10:42 AM, james McDougal  wrote:
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15) From: Barry Luterman
That is probably the most effective way. By stepping back you are using the
inverse square law for sound decay. Since the fan noise is essentially
a high frequency signal and the cracks are essentially clicks (transients
containing low frequency signals) the cracks will retain more sound energy.
My professional opinion.
On Wed, Jan 28, 2009 at 6:11 AM, Mike Koenig  wrote:
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16) From: Brian Kamnetz
Personally, I try to employ the inverse square law for sound decay
when ever I can... (just kidding, Barry!).
Brian
On Wed, Jan 28, 2009 at 12:12 PM, Barry Luterman  wrote:
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17) From: Cory Creighton
Barry,
You rock!!!  Your response is one of the many reasons why I love this list
and all those who respond.  Whether I'm looking for technical data or just
someones humble opinion, I can always find it here.
Cheers,
Cory
On Wed, Jan 28, 2009 at 11:19 AM, Brian Kamnetz  wrote:
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18) From: sci
Thanks Mike. That is sound advice.
Pause.
2nd crack is harder to hear on IR2 and I have to get real close to hear the
tiny crackles. Another visual clue, besides color, is the oil on the beans.
Another tip for hearing cracks on IR2: Program it to cut the fan speed down
right when first crack is usually starting. My three best profiles kick down
the fan speed right around 360F, this reduced fan increases temperature to
get the beans through first crack, and inadvertently, allows one to hear the
cracks easily.
Ivan
CA
++++++++++++++++++++++++++++++++++++++++=
Date: Wed, 28 Jan 2009 07:12:42 -1000
From: Barry Luterman 
Subject: Re: [Homeroast] IRoast 2 Tip Sheet
To: homeroast, koenig.mike
Message-ID:
       
Content-Type: text/plain; charsetO-8859-1
That is probably the most effective way. By stepping back you are using the
inverse square law for sound decay. Since the fan noise is essentially
a high frequency signal and the cracks are essentially clicks (transients
containing low frequency signals) the cracks will retain more sound energy.
My professional opinion.
On Wed, Jan 28, 2009 at 6:11 AM, Mike Koenig  wrote:
<Snip>
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19) From: Allon Stern
On Jan 28, 2009, at 7:40 PM, sci wrote:
<Snip>
Perfect, if you want to race to 2nd crack.
I have my iRoast programmed to warm up, then boost the heat (by  
cutting the fan) right up until 1st crack starts, then slack off a  
bit to coast through 1st and gently glide towards the EOR.
If you boost the heat through 1st crack, you're going to find the  
temperature increase to climb very quickly indeed.
I don't worry about hearing the cracks on the iRoast. I use a  
thermocouple, and watch it closely. I also watch the surface of the  
beans for color and surface texture changes (if I see oil, I know  
I've likely gone too far). You can see 1st crack in the temperature  
rise, and rate of climb - it seems to pause a little bit, gathering  
energy; if nothing is done at this point, it will rocket up heading  
for 2nd crack in about a minute. By reducing the heat input at this  
point, you can gently climb, making it to 2nd crack in about 4-5  
minutes, if that's your goal. Or you can even go slower and make it  
to a C+ in that time, with a proper application of foresight (damn  
iRoast doesn't have much you can do after a program is started) or  
external input (I use a variable speed exhaust fan to control  
temperature climb).
I find that this increases the yumminess factor, especially on the  
lighter roasts.
-
allon
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20) From: Douglas Hoople
Pardon me for being a bit dense, but you both are talking about manipulating
the fan speed as though that's a controllable element. It's not, is it?
Isn't temperature the only thing you can set when programming a profile?
Allon, you talk about moderating the heat after first crack. Do you have a
sample program (or a series of time windows) that you use to accomplish
that? Any chance you'd share it with us?
Thanks!
Doug
On Thu, Jan 29, 2009 at 9:11 AM, Allon Stern  wrote:
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21) From: Allon Stern
On Jan 29, 2009, at 12:35 PM, Douglas Hoople wrote:
<Snip>
Ignore the temperature reading provided by the iRoast. It is wildly  
inaccurate.
The only thing you can control is the "setpoint" and the time spent  
at that "setpoint". You may find (especially on 1st roast of the day)  
that the temperature reported by the iRoast is always well below the  
setpoint, making it really meaningless.
What isn't meaningless is that for temperatures below 395 (iirc) the  
fan speed is high, and above, the fan speed is low. This is about the  
only control you really have.
However, what I have done is attached metal dryer hose to the iRoast,  
run to a window-mounted exhaust fan; this exhaust fan draws air from  
the iRoast, and can vary the airflow depending on its speed; I drive  
the exhaust fan (a 12V muffin fan) with a 0-24V supply (haven't burnt  
it out yet on 24V :).
My profile will be useless unless you have a similar setup.
I ramp temperature to around 350 over the first 5 minutes or so, then  
I have a burst of heat to get "over the hump" into 1st crack. This  
heat boost I have strategically placed in stage 3 of the program so I  
can cut it short with the down-arrow button, if I'm going too fast.
I ramp the exhaust fan speed slowly over each program stage to draw  
it out.
Here's my setup:http://www.radioactive.org/pix/roaster/index.htmlOh, and the fan hasn't quit yet.
-
allon
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22) From: Douglas Hoople
OK, I sort of get it. What I was thinking was that you might set up 350 for
5 minutes, then run hot for a couple of minutes to get into first crack, and
use stage three for a more moderate temperature, but I can see that you're
ramping up to final temperature and accomplishing the moderation through
your exhaust fan.
I guess it would be threading the needle too finely to try hot in stage 2
and moderate in stage 3, wouldn't it?
BTW, why use the 'down' button to shorten stage 3? Why not just hit the
'Cool' button to stop it when you've reached the finish?
And yes, there's a lot of variation between what's on the onboard
thermometer and the thermocouple, and it's not consistent from session to
session, so I've long since stopped looking at it.
Thanks.
Doug
On Thu, Jan 29, 2009 at 10:28 AM, Allon Stern  wrote:
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23) From: Allon Stern
On Jan 29, 2009, at 1:47 PM, Douglas Hoople wrote:
<Snip>
Because I haven't reached the finish.
You can use the up/down button to lengthen/shorten the length of  
stage 3 *ONCE*. Since I have the maximum time programmed in, I can't  
lengthen it, but I can shorten it.
Stage 3 is my burst of heat. If I want the burst of heat to be  
finished sooner, because I've hit a solid 1st crack and the  
temperature is climbing quickly, I can end stage 3, and proceed to  
stage 4, which continues application of heat, but not as much.
-
allon
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24) From: Douglas Hoople
Allon,
You're absolutely right. I forgot that there are 5 stages, not 3. I've been
using the SM profiles up until now, and they only use 3 of the stages.
Yes, shortening stage 3 and stopping stage 4 makes perfect sense.  I'm
assuming that the time deducted or added is applied to the current stage and
not just to the tail end. I suppose you've confirmed that over time.
I'll add a couple of profiles to play around with the concept of a plateau
or slight dip in the ramp instead of a continuous climb.
Sorry to be a pest, but what temp do you set your stage 3 to? I know, I
know, without the exhaust, it won't be the same thing, but I'm just being
curious.
Thanks.
Doug
On Thu, Jan 29, 2009 at 1:41 PM, Allon Stern  wrote:
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25) From: Douglas Hoople
Hi Allon,
I've had a chance now to play with this a bit, and I've gotten the iR2
programmed to be able to set the plateau once 1st crack is underway.
My profile is as follows (the specifics are not as important as the overall
trend):
1) 320F for 2 minutes
2) 320F for another 2 minutes (see below for the explanation)
3) 460F for 3 minutes (with the intention of shortening)
4) 350F for 2 minutes
5) 470F for 5 minutes (with the intention of stopping at the desired degree
of roast)
Here's the strategy:
1) & 2) Slow ramp for 4 minutes. The iR2 tends to heat up in spite of the
lowest possible setting of 320F, and 4 minutes seems to be about right for
keeping the bean mass under 360F or so. More than 4 minutes, the temp seems
to creep toward 1st crack anyway.
3) After the ramp, time to kick the beans into 1st crack. Once in 1st crack,
hit the down button to push the timer ahead into 4). Today, I hit this at
around 415F when 1st crack was fully cranking after about 2 of the 3
minutes.
4) Trying to keep the temperature about where it is at around 415F. I don't
know if that's the right strategy (see questions below). Setting the profile
temp at 350F might be a little low, but the temps stayed above 400F through
the whole 2 minute "pause." Interestingly, the onboard thermometer drops
almost instantly to 330F while the thermocouple in the bean mass
reads consistently above 400F.
5) The drive to the finish at a high setting. 2nd crack seems to come a
little sooner than without the pause, which kind of makes sense because all
this extra time in the ramp and the "pause" has had the effect of heating up
the insides of the beans.
The coffee that came out of this experiment does seem to be an improvement,
with more sweetness, among other things. I don't know if I'm imagining
things, but I do like the resulting coffee better. Of course, this is right
after the roast with no rest, and only time will tell what it will be like
after a bit of rest. Sulawesi Toraja Sapan-Minaga chosen because it thrives
into 2nd crack and I wanted to test the full curve.
So I guess I have a couple of questions:
How far into 1st crack before shortening stage 3 to start the pause?
What should the plateau look like? Stay at the same level? Drop a few
degrees?
How long should the pause be?
When does this profile cross over from "optimal" to "baked"?
Finally, the reason I set Stage 1 and Stage 2 at the same temperature was to
use them up. Shortening Stage 2 and shortening Stage 3 yield different
behaviors. When you try to shorten Stage 2, the time is taken from the end
of the whole roasting cycle, and the stage runs its full duration anyway,
which is exactly what's not desired. For whatever reason, when you shorten
Stage 3, it will advance to the next stage rather than staying in the
current stage, which is the desired effect. Just the way Hearthware
engineers built it, probably just an unintended "feature."
I'll be interested in any feedback to this enjoyable experiment.
Thanks!
Doug
On Thu, Jan 29, 2009 at 1:41 PM, Allon Stern  wrote:
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26) From: Mike Sieweke
On Jan 29, 2009, at 1:28 PM, Allon Stern wrote:
<Snip>
The temperature/fan ranges are:
320-385 - high fan
390-410 - medium or high fan
415-485 - low or medium fan
The first 3 minutes are limited to high fan mode, no matter what the
programmed temperature is.
I usually program high fan mode (385 programmed temp) for the whole
roast.  The down side is that I can rarely hear second crack.  The
beans peak at >440 degrees, depending on the amount of chaff.  If
the temperature doesn't rise quickly or far enough (as with decaf),
I block part of the air flow with a wooden spatula.
Mike
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27) From: Allon Stern
On Jan 29, 2009, at 5:23 PM, Douglas Hoople wrote:
<Snip>
Okay, finally found a past post (I have the profile written down next  
to the roaster, but I'm not next to the roaster :)
HTH:
On Jul 10, 2008, at 10:47 AM, Allon Stern wrote:
<Snip>
FOOTNOTE: I haven't had to stretch it.
<Snip>
-
allon
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28) From: Douglas Hoople
Hi Allon,
Thanks for this description. This answers most of the questions in the
followup post, so you can ignore them, for the most part.
I find it interesting that you never set the setpoint higher than 395F, even
at the highest setting.
It's clear, too, that your exhaust fan setup gives you a lot of control over
the curve of the roast.  I noticed that, for example, while you do stretch
out the time between 1st and 2nd crack, you don't let the temperature drop.
It appears that there's a continuous rise from 406 at the end of your stage
3, and you don't let the temperatures drop at all even with the lower set
point temperature.
In my experiment yesterday, I did let the temperature drift down from 415 to
405.  Without the exhaust fan, that's a little hard to prevent, and
I'll have to work on it. Because I don't have a lot of experience with this
yet, it's hard to tell, but I think I might have baked the roast a little,
judging by my morning cup after 15 hours rest.
Thanks for all the information you've provided, Allon. It's very intriguing
to try to find that extra depth that the "crack stretchers" all seem to talk
about.
With the iR2, there seem to be two basic themes.
First, that the long initial ramp is essential to preventing an "air
roasting" effect, namely that air roasters, being faster at heating, have a
tendency to not heat the insides of the beans to the level of the outsides.
The long ramp provides the chance to even things out, and provides a base
for a more "normal," more satisfying roast.
Second, that whatever it takes to stretch out the time between 1st crack and
2nd crack is worth it, as long as you don't stall the roast. This stretching
of that interval, by most of the reports that have appeared here, allows the
flavors to "develop more fully." I think I've seen enough hints of that in
one of yesterday's experiments to keep working at it, but I've also baked a
lot, too.
The problem with the iR2, of course, is that it's hard to manage these. The
initial ramp is not so tough, but stretching out the cracks takes a LOT of
finesse, and so is only worth it to the most particular (read: rabid, crazy)
of the iR2 owners.
Looks like I might be moving into that category. Should I warn my wife? :-)
Doug
On Fri, Jan 30, 2009 at 5:50 AM, Allon Stern  wrote:
<Snip>
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29) From: Douglas Hoople
Wow!
Sign me up as convinced!
I'm sitting here drinking two cups of coffee, one from a batch roasted on
the iR2 as follows:
350F for 3 minutes
400F for 3 minutes
450F for 3 minutes
the roasted as follows:
320F for 4 minutes (in two stages combined)
460F for 2.5 minutes (shortened from 3 minutes)
360F for 2 minutes
470F for 5 minutes
Note that iR2 setpoints under 400F are generally 20-30 degrees lower than
what the temperatures shown on the bean mass thermocouple, so the 400F on
the first set allows temperatures to rise well into first crack (410-420).
So the first profile, while it has a slowish ramp for the first 3 minutes of
Stage 1, features a full and relatively steep rise from Stage 2 to the end.
The second profile features a slow ramp for 4 minutes, takes a while into
Stage 2 before hitting first crack, and then stretches out the time from 1st
to 2nd crack.
OK, so back to the side-by-side tasting...
The claim that a longer initial ramp and stretching the time between 1st and
2nd crack appears to have real merit. The cup from the first roast has a
kind of "edge" on the front end that simply isn't there on the second. The
second cup is smooth and balanced.
Reaching for a metaphor, it's a little like the difference between "good"
stereo speakers and "audiophile" speakers. Good speakers sometimes are tuned
edgier to spike certain qualities, whereas really great audiophile speakers
are smooth and even across the entire sound spectrum.
I've seen that description in people who move from air-roasters to
drum-roasters. They notice that the coffees are "more muted," which I think
translates to that smoother, more balanced, more even quality that I'm
noticing in the "long-ramp cup" I'm drinking right now. And I've seen
reviews of the iR2 that suggest that slower ramps overall are required to
ensure even roasting into the centers of the beans. This is all consistent
with what's in the cup, so I think I'm signed up.
Am I imagining things?
Thanks.
Doug
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30) From: Allon Stern
On Jan 30, 2009, at 10:31 AM, Douglas Hoople wrote:
<Snip>
I'm just grateful this isn't the homeplumbing list..
<Snip>
Seems about right.
<Snip>
I think you've got it. Roasting is a cooking process. Developing  
flavors can take time.
<Snip>
Yep. I still may play with PIDing an IR2, and totally doing away with  
the built-in microcontroller.
<Snip>
Possibly. Note that I've mostly gone to doing heat gun roasting  
because I can get larger batch sizes, and have much more control than  
even the modified IR2.
-
allon
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