HomeRoast Digest


Topic: temperature (18 msgs / 634 lines)
1) From: MS
I have been roasting 100 grams with a conventional barbecue thermometer  in my popper and have been having some good luck with it.  I get to a city roast at around 425 degrees after around 8 or nine minutes and a city + when I go longer to 435 to 450.  In some ways this sounds similar to the profile at Sweet Maria's, though it really is not.  First of all, my roast goes very fast at the beginning.  I am up to 270 degrees within a minute or two even with the popper cover off and keeping the thermometer right in the mass of beans constantly.  Within 4 minutes I am up to around 375 degrees (I think in the SM profile I should be up to 270) and my roast getting a pretty dark tan color.  At that point my roast slows down or even stalls and to keep it going I put on the hood of the popper, which has a hole in it for the thermometer.  Throughout, I have the thermometer in the mass of beans, though they are moving around the thermometer.  The roast then moves slowly but steadily up in
 temperature and I finish in the midst of or towards the end of first crack. The beans are happily snapping away and caramelizing.  I assume that what is happening is that because of the type of thermometer I am using I am measuring mostly the ambient temperature in the bean chamber. I am at City, maybe at a slightly dark city roast when in the SM profile I should be at City +.   There seems to be a 100 degree difference between my temp reading and the profile at SM's at the beginning (mine being hotter), though I end up with a lighter roast.  Does anyone want to venture a guess with regard to the degree of difference between the ambient temp and bean at the beginning of the roast and at the end? I am assuming that they are different; the beans are heating up much faster in the beginning than at the end.  At the end I must have reached the hottest that the popper can reach and it is probably the beans that are carrying the temperature up. Based on your experience with sound, 
 color,
 taste, and using the kind of thermometer I have been using, I am just curious how much difference you figure there might be between the true bean temp and what I am measuring (a combination of chamber and bean)?
I should add that I end up liking my coffee.  I am not sure it is nirvana--like some here describe when they have a good cup-- either because I am not a good critic, or because the roast is just mediocre.  In other words, I can't tell if mine is a case of how it is hard to ruin a good bean and there is lots of room for improvement or if this is as good as it gets  (and i do enjoy my coffee.  I have been drinking a coffee labeled "Juan Valds" that someone brought me, pre roasted, directly from Colombia, probably roasted within no more than a week before it was given to me.  It is darker than mine--mine is a Mexican roasted to City--and I like mine just as much if not more.)
---------------------------------
Do you Yahoo!?
 Yahoo! Mail - now with 250MB free storage. Learn more.

2) From: Edward Spiegel
At 10:38 AM -0800 1/08/05, MS wrote:
<Snip>
With this type of thermometer, you are getting a lot more of the popper air temp whan with a bead-type thermocouple and you have considerable latency built-in. (Remember that these thermometers take many many seconds to respond to changes of more than a few degrees -- so when your popper's heater stalls momentarily you won't see the temperature drop for 15 to 20 seconds). And, at the beginning of the roast the air is heating up much faster than the beans so the temp reading isn't a strong indicator of bean temp for several minutes.
These type of thermometers with their long shafts don't just measure the temp but also conduct heat. They are pretty reliable as long as your roasting technique stays fairly constant BUT the latency is such that if you do things to stretch or speed up the roast, you won't have it register for a while. A well-placed bead type thermocouple will response MUCH faster than one of these thermometers. It takes a little practice to get the placement right (if it is too close to the vents the air temp will figure too heavily in the temp readings, but once you have it, you can track the changes in the bean temp pretty well.
No matter what you do, it will take a few roasts to 'calibrate' the correlation between your temperature readings and SM's. I recommend doing several roasts where you log the temp readings at first crack outliers/rolling first crack/end of first crack and also second crack outliers/rolling second crack. You can then compare the temps to the SM-given temps and come up with a rough correlation.
Note that the new visual roasting guide seems much closer to the temps that I get than the old one.
If you are roasting in a popper where you have ready access to the fragrance and sound of the roast, you may find that the process of calibrating your thermometer also gets you calibrated so that you no longer need the thermometer.
Just my .02,
Edward

3) From: Ed Needham
Short answer...
You wondered why your air roaster temps didn't match those of Sweetmaria's 
roast profile?
Air roaster temps don't correlate with drum temps to get the same roast. 
Variables include, smaller batch, fast moving air, higher air temps, form 
and speed of agitation...among other things.  Jim Schulman used his modified 
air roaster to try to match my drum roaster temps at all points throughout 
the roast.  His result was significantly different than mine using beans 
from the same batch.  He ultimately matched the taste of my beans fairly 
closely, but without trying to match my temps.
Other things to compound the differences might be that thermometers sense 
temperatures differently when air is fast moving verses that in a drum, 
which is fairly static comparatively.  Input air in an air roaster is +/- 
500F, where drum roasters utilize lower temps.
Bottom line is that it's likely the elusive 'bean' temperature is likely 
very similar in a drum or an air roaster.  Heat transfer in an air roaster 
is much quicker, but as Ron Kyle and have shown using a 57 RPM drum motor, 
the faster it turns, the quicker the roast.
Not sure how much this adds to answering your questions, but I'll hit send 
now and you can take it for what it's worth.
*********************
Ed Needham
"to absurdity and beyond!"
ed at homeroaster dot com
(include [FRIEND] somewhere in the subject line of any email correspondence)
*********************

4) From: Tom Ulmer
Agreed. 
I think the temperature readings are just a relative way of discussing =
"this
is what I am generally doing". When two cooks discuss stovetop cooking
methods they can say "with the pan at a medium low temperature" and =
there is
a relative consensus on the meaning. Communicating your process can be
taxing even when one thinks "I know what you know".
My absolute favorite effective communication phrase is "over there". 
I fall for this one every time.

5) From: Justin Marquez
My favorite Southern-speak phrase is "I'm fixing to go over yonder".
Everybody down here knows what you mean when you say that.
Safe Journeys and Sweet Music
Justin Marquez (Snyder, TX)http://www.justinandlinda.comOn Mon, 10 Jan 2005 09:01:37 -0500, Tom Ulmer  wrote:
<Snip>

6) From: Jean
Mine is regarding 'being out of pocket' - it took quite a while before I =
learned it meant being unavailable, not out of cash!
 
Jean  =~/

7) From: Paul Helbert
For years, our primary brewing method has been pour over paper filter
supported by a little #2 Melita plastic portafilter. I have other
methods which do better but none that are easier, so it is that I
enter the kitchen, put the kettle on, grind the beans, warm the cup
and brew. I've been doing about what I have seen recommended in coffee
circles as to temperature: remove kettle from heat at full boil, wait
ten seconds and pour enough to wet the grounds, return the kettle to
the heat, repeat the ten second cool off and pour the remainder. Well
recently I was calibrating thermometers and decided to check the
temperature of the infusion. Too low! In order to get 200F I need to
be doing those pours right off the stove, not with a ten second delay.
This is at  70F ambient. Elevation about 1000 ft (high pressure, front
went through here a day ago).
You might want to check your results.
-- 
Paul Helbert
Prepackaged, roasted & ground coffee,,,
Some of the worst ideas since sliced bread.
Homeroast mailing list
Homeroasthttp://www.homeroasting.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.homeroasting.com/gallery/main.php?g2_itemIdx20

8) From: webviking6
I'm in Denver, where water boils (usually) somewhere between 202 and 205 
degrees Fahrenheit.  I use a French press, so I pull my kettle off the 
stove wait just a second for the boil to subside and pour in the water 
immediately. My kettle, though, is a heavy thing that holds a lot of 
heat, I don't think waiting ten seconds would drop the temperature much 
below 200 degrees.  The downside of that is that it takes longer to get 
the water heated up.  I also boil about twice as much water as I need, 
and after I fill the FP, I fill my cup and my thermal carafe with almost 
boiling water to heat them up.  Within 3 minutes the temperature of the 
infusion in the FP has dropped to around 190 degrees, which I think is a 
little low.  I've been thinking of getting a thermal FP.  Starbucks 
sells crappy ones for $50 and I haven't been able to bring myself to 
spend that kind of money on a piece of junk like that.  A thermal FP is 
kind of an oxymoron anyway, because  the whole idea of using a FP is to 
pour off the coffee as soon as it's done brewing, the last thing you 
want to do is let it sit around in the grounds for an hour or two.  The 
only possible reason for having a thermal FP is if you are a twisted, 
obsessed nut like me that worries about tiny things like heat loss 
during the 3 to 4 minute steeping time.
I can't tell you how nice it is to have found a whole list of twisted, 
obsessed nuts like me :).
Paul Helbert wrote:
<Snip>
Homeroast mailing list
Homeroasthttp://www.homeroasting.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.homeroasting.com/gallery/main.php?g2_itemIdx20

9) From: Bill
Someone, it might be Ivan (IIRC), uses beer coozies to insulate his glass
carafe for the FP.  sez it works pretty good.  the *$ is really crummy.
 don't go that route.  I think someone else wraps a towel around the carafe.
good luck
bill in wyo
On Wed, May 14, 2008 at 6:55 AM, webviking6  wrote:
<Snip>
Homeroast mailing list
Homeroasthttp://www.homeroasting.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.homeroasting.com/gallery/main.php?g2_itemIdx20

10) From: sci
The beer coozie/hugger works perfectly on the small presses, but it does
increase cleaning time. I just got a large glass double wall Bodum Bistro
press and it is really nice, hefty. It insulates fantastically. I'm going to
try it on the Qishr since Tom said to steep 10 -15 min. I too found that to
get 202F water I have to pour immediately from a full rolling boil. By the
time the water hits the grounds, the temp drops to the 205F range. I tried
three thermometers and all said the same. I live at about 500ft above sea
level.
Ivan
++++++++++++++++++++++++++++++++++++++++++
Date: Wed, 14 May 2008 15:59:41 -0600
From: Bill 
Subject: Re: [Homeroast] temperature
To: homeroast
Message-ID:
       <22428b320805141459h6fee989clea3f214799363766>
Content-Type: text/plain; charsetO-8859-1
Someone, it might be Ivan (IIRC), uses beer coozies to insulate his glass
carafe for the FP.  sez it works pretty good.  the *$ is really crummy.
 don't go that route.  I think someone else wraps a towel around the carafe.
good luck
bill in wyo
On Wed, May 14, 2008 at 6:55 AM, webviking6  wrote:
<Snip>
stove
<Snip>
I
<Snip>
FP
<Snip>
been
<Snip>
I
<Snip>
of
<Snip>
if
<Snip>
like
<Snip>
Homeroast mailing list
Homeroasthttp://www.homeroasting.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.homeroasting.com/gallery/main.php?g2_itemIdx20

11) From: Rich Adams

12) From: Bill
Ivan,
hadn't seen the double-walled.  not sure we should be talking about it,
since it is a direct competitor for something that Tom sells, since he's in
the French Press market and he pays for the list.  Not to be a
whistle-blower...
but still, hadn't seen one... do you pre-heat it?  I know, violating what I
just said...
bill in wyo
On Wed, May 14, 2008 at 6:00 PM, sci  wrote:
<Snip>
Homeroast mailing list
Homeroasthttp://www.homeroasting.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.homeroasting.com/gallery/main.php?g2_itemIdx20

13) From: raymanowen
"...twisted, obsessed nuts like me :)."
Hi ya! Me, too.
I'm at 5316* ft in Westminster- looked like 201F - 202F at full boil.
*Haven't checked this apartment's elevation, yet- maybe lower than 5300ft.
Bob Gardner of Instrument Service Co. in Denver told me not to reset the
precision slide wire power supplies in thermocouple chart recorders to give
a scale reading of 212F. CSM Research Institute, under the "M" on Mt. Zi=
on
above Golden, is higher altitude than Denver or Westminster.
"You guys got Mercury thermometers- I sold 'em to you. Calibrate against
them." I always assumed the ice water bath and boiling water bath were good
standards at 0C and 100C. Rong and Rong again. Clumsy people shouldn't
touch those expensive babies.
I boil the cone filter basket of the TechniVorm while I grind into the Gold
mesh filter. That way, not Everything is 130 cooler than the brewing wat=
er
coming out the arm, so I don't have to invoke Magic to imagine it stays at
200F while the coffee brews.
Actually, I use water at a full boil right out of a tea pot to fill the
filter basket. The bloom is almost volcanic, so I dribble water from the pot
to knock down the bloom as I fill it. I only turn the TV On for the last
couple of ounces at the end to wash down the grounds from the sides of the
cone, fill the stein and give a little sample cup.
It's already brewed for 4 minutes, so I close the valve for another minute
then open it full after the wash down. It's a long brew, maybe, but even
these tailings are good with the grinder set to 50.
Iechyd da, Mabuhay -RayO, aka Opa!
Got Grinder?
On Wed, May 14, 2008 at 6:55 AM, webviking6  wrote:
<Snip>
ove
<Snip>
, I
<Snip>
 FP
<Snip>
een
<Snip>
d I
<Snip>
of
<Snip>
if
<Snip>
ke
<Snip>
ee.com
<Snip>
-- =
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Mighty
Wichita (ex- NYC Paramount) WurliTzer- 1976
Homeroast mailing list
Homeroasthttp://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee=.com
Homeroast community pictures -upload yours!) :http://www.homeroasting.com/=gallery/main.php?g2_itemId=7820

14) From: Morris Nelson
The best advice you can give a retailer is when something can be changed to
improved customer satisfaction.  Tom's response ought to something like
"thank you".
Morris

15) From: Coffee
Bodum makes several thermal FP models... but I wouldn't want the  
coffee sitting around with the grounds for any length of time. Better  
to pour the coffee out into a thermal flask or some such thing...
-Peter
On May 14, 2008, at 9:02 PM, Rich Adams wrote:
<Snip>
Homeroast mailing list
Homeroasthttp://www.homeroasting.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.homeroasting.com/gallery/main.php?g2_itemIdx20

16) From: sci
Bill,
I do preheat my presses. It is simple. I pour in an inch or two of boiling
water and let the glass and plunger heat up while I grind. The hot water
also helps to clean the press of any old residues. I more than once ruined a
press of nice coffee just the way someone else here did with soap. My lovely
wife likes to wash stuff by hand and thinks a full squirt of soap is needed
for each dish. So sometime she washes my presses with lots of soap and they
dry out, hiding residue. Often I pour in my preheating water and, lo and
behold, the power of soap suds. Yeeech! So I thoroughly rinse with hot water
till clean. So preheating helps with more than temperature for me. The
huggie/coozzie or double-wall press helps to keep a very constant
temperature for a systematic extraction. I have measured this with
thermometers. With a coozie on a small press, I pour boiling water in the
preheated press and it usually yields  204F. It will drop about 1 degree F
per minute. So after three minutes it is down to 201F. I get wonderful and
consistent results this way. Only problem is the coozie can get dirty. The
double-wall glass press is the next generation press. But I don't leave my
coffee in the press more than 4 minutes, even though Bodum says the press
will keep the coffee hot for over an hour. We all know the problem of
overextraction. So why bother to insulate a press? It gives a precise
initial extraction. It works even better with tea, which can steep much
longer.
Ivan
+++++++++++++++++++++++++++++++++++
Date: Wed, 14 May 2008 22:08:36 -0600
From: Bill 
Subject: Re: [Homeroast] temperature
To: homeroast
Message-ID:
       <22428b320805142108x2be98826t4d8c2582328289d3>
Content-Type: text/plain; charsetO-8859-1
Ivan,
hadn't seen the double-walled.  not sure we should be talking about it,
since it is a direct competitor for something that Tom sells, since he's in
the French Press market and he pays for the list.  Not to be a
whistle-blower...
but still, hadn't seen one... do you pre-heat it?  I know, violating what I
just said...
bill in wyo
On Wed, May 14, 2008 at 6:00 PM, sci  wrote:
<Snip>
to
<Snip>
Homeroast mailing list
Homeroasthttp://www.homeroasting.com/gallery/main.php?g2_itemIdx20">http://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee.comHomeroast community pictures -upload yours!) :http://www.homeroasting.com/gallery/main.php?g2_itemIdx20

17) From: kofi
  I'm at about 100 ft in San Diego and use french press daily.
I have a PID on the electric kettle to get just the right temp I want for
coffee. It started out as a way of saving time in the morning so as not to
have to wait for the water to cool some before I pour over the grounds.
  Now after using this for some time we find that we like most coffee with
water temp starting off at 197 or 198 F in the kettle then poured over very
coarsely ground coffee and steeped for 4 minutes.  Very rarely and depending
on the coffee we may go over 200.
  One thing we have found is that coffee that hasn't degassed much tastes
better when brewed at a lower temperature and that as it gets older raising
the temperature a few degrees brings back the edge to it. Depends on the
coffee. I had thought that such changes in taste were confined to the realm
of espresso and was quite surprised how much a degree or two can make in the
taste.
I haven't bothered with pre-heating the french press as a rule as when I
tested it out a long time back I couldn't tel any difference in the cup
either way.
Courtesy of Steve Ackman here's a great way to calibrate your thermometers
using the weather service:http://twoloonscoffee.com/map/boiling_point.phpJohnny
On Thu, May 15, 2008 at 1:28 AM,  wrote:
<Snip>
l.
<Snip>
ve
<Snip>
Zion
<Snip>
od
<Snip>
n't
<Snip>
ld
<Snip>
ater
<Snip>
00
<Snip>
he
<Snip>
he
<Snip>
ee.com
<Snip>
ee.com
<Snip>
Homeroast mailing list
Homeroasthttp://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee=.com
Homeroast community pictures -upload yours!) :http://www.homeroasting.com/=gallery/main.php?g2_itemId=7820

18) From: Bill
Interesting.  Thanks for the precision, Johnny.  Good to know about your
findings.  And thanks for the boiling point computation.  I had found
another, but your site is better.  Thanks.bill in wyo
On Thu, May 22, 2008 at 11:00 PM, kofi  wrote:
<Snip>
ry
<Snip>
ng
<Snip>
lm
<Snip>
oil.
<Snip>
ldn't
<Snip>
er
<Snip>
ve
<Snip>
ne
<Snip>
ee
<Snip>
y.
<Snip>
nt
<Snip>
ee.com
<Snip>
ee.com
<Snip>
ee.com
<Snip>
Homeroast mailing list
Homeroasthttp://lists.sweetmariascoffee.com/listinfo.cgi/homeroast-sweetmariascoffee=.com
Homeroast community pictures -upload yours!) :http://www.homeroasting.com/=gallery/main.php?g2_itemId=7820


HomeRoast Digest