HomeRoast Digest


Topic: iR2 thermocouple position (5 msgs / 161 lines)
1) From: Douglas Hoople
Hi All,
I just got a digital thermometer and thermocouple with my last coffee order
at SM, and worked up the courage to fit it onto my iR2 last week. No big
deal, once it was done, but I did need to see the writeup and pictures on
the SM website (thanks yet again, SM!!).
The first couple of roasts went flawlessly. I'm sold on using the
thermometer to help gauge where I am in the roasting curve.
I've discovered, though, that the thermocouple tip can't be too close to the
air column (or, at least, that's what I think the problem is). If it is, it
will read too hot. I got caught panicking and believing the thermometer at
face value and underroast two batches (see my other thread on the Brasil
Daterra).
For the latest batch, I re-positioned the thermocouple in the bean mass, but
away from the air column, and I'm back on the numbers.
So the question is: are there any tips for thermocouple placement in the
iR2? Is this a binary thing, where you're either too close or you're not? Or
are there gradations and subtleties beyond that that we should be aware of?
Thanks.
Doug
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20

2) From: Terry McVay (rr)
Great question, and if I may add one.. Placement in the RK Drum.  Saw a
picture a while ago from Les, I think, but cannot find it now..
Terry..

3) From: Mike Sieweke
I haven't made a scientific study of all possible locations.  I suppose
it's more important that it be consistent, so you can compare your
results from one roast to another.
I used ideas from this site to put a thermocouple in from the bottom:
   http://alpete.com/pictures/main.php?g2_itemIdR9I think mine is about 3/4 inch away from the glass, and 1/2 inch up
from the metal bottom.  It starts out at the top of the bean mass, but
the beans cover it after they expand during the roast.  I did a lot of
roasts with this setup, and the results were very consistent.
Mike
On Jan 19, 2009, at 3:02 PM, Douglas Hoople wrote:
<Snip>
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20

4) From: Douglas Hoople
Hi Mike,
Thanks for all the pictures! It takes all the guesswork out of what you're
doing.
I think you're right... getting the sensor into the bean mass somewhere
between the column and glass gets pretty consistent results.
I've got the probe snaked through the lid, and I have to reposition the
sensor with every roast. I also have to pull it apart to clean out the
chaff, and I can tell there's substantial wear and tear on the thermocouple
from all that extra movement.
Your method addresses both these problems. I'm going to have to try it soon
Thanks!
Doug
On Tue, Jan 20, 2009 at 8:44 PM, Mike Sieweke wrote:
<Snip>
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20

5) From: Allon Stern
On Jan 20, 2009, at 11:44 PM, Mike Sieweke wrote:
<Snip>
I ran mine in from the top and was able to get very consistent  
results, HOWEVER without some way of controlling the roast, you  
have...well, no control. And the iRoast gives you very little actual  
control.
And the batch sizes are too small.
Ever since the gathering at Paul's place, I've been using a heat-gun.  
It's much more hands on - I think everyone should try it even if they  
don't stick with it. Nothing like having all your senses in the  
roast, while roasting in an open container. I've been doing 1/2lb  
(green) batches, and most recently brought a batch of Guatemala  
Oriente DP to C+ in 16 minutes - wow, what a great bean. The absolute  
control of HG roasting really is fun, but you have to pay attention,  
and not rush it. I just wish I had a good way to measure bean mass  
temps while roasting. Maybe I'll lash up an IR unit in some way.
-
allon
Homeroast mailing list
Homeroasthttp://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.sweetmariascoffee.com/gallery/main.php?g2_itemIdx20


HomeRoast Digest