HomeRoast Digest


Topic: Thermometer + Tom's roast pictorial (4 msgs / 119 lines)
1) From: Borgie
I'm expecting a shipment today from SM's and tucked amongst the six
pounds of Coop 15 de Septiembre, La Minita Terrazu, and Sipi Falls
will be a shiny new Cooper thermometer.  In your experience, do the
measured temps correspond fairly well with Tom's roasting pictorial? 
I've been roasting for a few months now with great success, but I need
to start obeying the control freak inside.  Speaking of which:
Knock knock
Who's there?
Control freak -- now you say "Control freak, who?"
!
-Steve

2) From: Edward Spiegel
Hello,
What equipment are you using to roast? The short answer is that the numbers you see on the thermometer will not match the numbers in the roast guide. There are several reasons. One is that this style of thermometer has a lot of latency. So, it takes a while for temperature changes to register. The other is that if you are using an air popper, when the air is flowing you are getting a temp that reflects some combination of the heat of the air stream and the heat of the beans. YOu can use the thermometer as a rough guide but you will have to chart the temps you get at first crack and second crack and compare them to what you see in Tom's chart to get a rough idea of how your temps translate to his.
I hear that the digital thermometer sold by SM's has much less latency (I can't vouch for this as I don't have one). There are also non-contact infrared thermometers that are accurate and have very little latency.
I find with air poppers that my nose and ears and eyes are able to track the roast stage better than the thermometers I tried were. Since the thermometer is always telling you where the beans were 10 to 20 seconds ago.
That's just my .02.
Edward
At 8:10 AM -0700 9/17/04, Borgie wrote:
<Snip>

3) From: Borgie
I'm using an assortment of air poppers -- a Pumper outfitted with a
soup can is the current weapon of chaff destruction.  My trouble area
is the space between City and Full City and I thought the thermometer
would help guide me.  I agree about the eyes, ears, and nose being the
best tools of all.  I suppose if I got off of my lazy arse and logged
some basic information, I could probably do without the thermometer. 
Hmmm....a lazy control freak.  That has to be the worst combination of
all.
I appreciate your opinion, Edward.
-Steve
On Fri, 17 Sep 2004 09:17:53 -0700, Edward Spiegel
 wrote:
<Snip>

4) From: Felix Dial
Happy Friday,
I stuck the thermometer through the top of the butter dish of my poppery2
and I've been roasting using time and temp ever since. I eventually got a
digital multimeter and thermocouple (TC) setup and it certainly is the case
that there is some lag with the thermometer. The TC is much more responsive
and the difference between the temp readings is most noticeable, at least in
my old setup, at the beginning of the roast to about 350F. The temp readings
were close from that point till the end of the roast; my temp ramp slowed
down during and post 1st crack till the finish so the readings from the TC
and the thermometer were almost identical.
I've only been roasting since July of last year, so I don't have the
experience to see, smell, and hear the difference between City/City+ and
Full City. These roast levels are post 1st and pre 2nd (for me anyways) so
there aren't any audible clues. Different beans have different roast colors
at the same roast temp, so I can't rely on visual clues.  And I try not to
smell the roast exhaust as I get way too caffeinated doing this.  I can't
"sense" when a roast is at City+ or at Full City, but I can look at the temp
readout to see if I've reached 435-437.5F (for City+) or 442.5-445F (for
Full City).
But what's neat is that ever since I PID my roast setup, I can pay more
attention to the sensory clues as the PID is driving the roast by temp for
me.
I posted a message a few weeks back asking folks if the temps on the
sweetmaria's roast pictorial was comparable to what they were getting.
Here's the link to the thread at the archive:http://www.themeyers.org/cgi-bin/nopre.cgi/HomeRoast/Topic13028.htmCheers,
   Felix


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