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Topic: 180 Degree Coffee Pot Experiment (8 msgs / 324 lines)
1) From: Walter R. Basil
The entry of my blog today:
The purpose of this experiment was to see if having a coffee pot that  
keeps the water at 180 degrees is qualifies it as a defective unit.
Many people talk about the advantages of brewing coffee at a certain  
temperature - about 195 degrees F. I've heard people slam coffee pots  
that just don't seem to brew at that optimal temperature. I'm sure  
that very few can. Many factors come into play when trying to attain  
that perfect temperature. Little things, like physics.  That "ideal"  
temperature is based off a boiling point for water at sea level, 212  
degrees F, and a given barometric pressure.
So what about other locations? Are we just out of luck? I have two  
Bunn coffee brewers. Both pour their water out at 183 degrees F in  
the streams from the shower-head. I don't believe anyone can get  
their coffee to brew at that perfect 195 degrees without going  
through some special effort.  Why? Try it out! I did some tests of my  
own. Real world, real experience tests. Get yourself a good food  
thermometer, a pan for boiling water, a container for pouring the  
water into afterwards (how about your coffee pot?), and some water (I  
used a full coffee pot's worth of water).
First, let's take this perfect sea-level boiling water. It has to be  
at a rapid boil to be 212 degrees. Any mineral and chemical additives  
change the composition of water, therefore changing the boiling  
point. You'll have to take into consideration the temperature of your  
filter basket and your coffee pot, along with the already quick  
dropping temperature of the water. In reality, no one is going to pre- 
heat their filter basket, or coffee pot. Water sitting in the pot on  
the burner does not count for my temperature reading because the  
coffee flavor has already been extracted. Now it's just cooking and  
will eventually burn.
Second, consider the temperature lowering variables. Water already  
has a rapid fall off point for the temperature as soon as it is  
released from the heat source. I'll call this the rapid fall off  
band. By rapid, I'm talking it drops 12 degrees or more within 30  
seconds.  That's physics folks. You can't change that. Combine this  
quick fall off with the initial temperatures of the filter basket,  
grounds, and especially the coffee pot, and you are losing even more  
heat. Why especially the coffee pot? Because of the huge surface area  
of the inside of the pot that your coffee will be touching. Think of  
pouring a teaspoon of hot coffee on to a room-temperature spoon. You  
can immediately put it in your mouth without being burned because the  
spoon has lowered the temperature of the coffee by that much. Now  
compare the surface area of the spoon against that of the interior of  
the pot. Much bigger; you'll get much more "cool-down factor" from  
the pot. Then there's the coffee that's already cooled down a bit.  
That's going to drag your over all temperature down. The first cup of  
water is going into your room temperature coffee grounds and filter  
basket. That's going to bring down the temperature. Then that already  
cooled off coffee is going into a room temperature coffee pot,  
dramatically lowering the temperature from what it was already  
lowered from in the filter basket. By the time the second cup of  
water comes through the filter basket, the grounds are already heated  
up so the temperature won't drop too much more at that point. But  
when it drops into the coffee pot, it will lower the temperature some  
more; because of the mixing with the other cup of coffee that's in  
there, along with the sides of the coffee pot. Not as fast as the  
first cup cooled down, but a little bit of cooling down nonetheless.  
As the rest of the coffee brews into the pot the temperature will  
begin to raise a little as it mixes with more hot coffee.
At my elevation, the boiling point of water is 205.7 degrees F, with  
a barometric pressure of about 30 (when I did this test). My digital  
thermometer was off by 2/5ths of one degree, or maybe the difference  
is because of the chemicals in our beautiful city's water; even  
though I run it through a Brita filter. The hottest reading I could  
attain in the boiling water was 205.3. When the water began to boil,  
my reading was 196. It didn't reach 205.3 until it was at a rapid  
boil for about a minute. I removed the water from the heat source and  
the temperature immediately dropped by almost a degree a second for  
initial few seconds. The ambient temperature in my house was about 70  
degrees. I poured the water very quickly into my coffee pot watched  
the reading continue to drop during this rapid fall off band. The  
water seems to be able to hold its own temperature for a little bit  
when it hits the 180 degree area. That's when it takes longer to cool  
down. As a side note, this was all done with water.
There is a big difference between the actual brewing process and my  
test that I'd like to mention because it shows that even with the  
test that I did, the liquid will cool down at an even faster rate  
than what I described in my experiment.  I poured my water in quickly  
once it boiled. In a real brewer, the water trickles through by  
comparison. This will drop the temperature even more. Think of it in  
terms of the radiator in your car. You take the hot liquid and divide  
it up into smaller streams of liquid in order to cool it down faster.  
Just this act alone can keep your engine relatively cool. The fan on  
your radiator is not constantly on to keep it cooled down.
In summary, if you check the temperature of the water in the coffee  
pot immediately after it fills and see that the temperature is 180, I  
don't think you have a defective unit; especially if you live in a  
higher elevation environment. In my case, I read 183 degrees coming  
from the shower-head. I have to assume by the time it reaches the  
shower-head it has already cooled off a bit. I would guess either 184  
or 185 in my holding tank (I'm not about to open it to find out and  
void my warranty). If my water begins to boil at 196, that means my  
water would have to continually be heated just to the beginning of a  
boil in order to maintain that "perfect" temperature for brewing  
coffee, and that's just impossible for this elevation. Bunn's are  
made at the factory a certain way and they'll have varied results at  
different elevations, aside from the normal slight variance naturally  
occurring in the production line. I don't know this for a fact, but I  
would imagine that they make one home model that is set up with a  
universal temperature because of these differences in elevation. You  
don't want to have a machine that is thermostatically set to hold  
water at 196 - 202 degrees if that is going to be a constant boil in  
some locations.
I took Tom's advice from their Tiny Joy newsletter and brought water  
to boiling, removed from heat, and manually brewed some coffee using  
the same amount of water and grounds, with about a 3 minute brewing  
time. This put my temperature at 187 degrees when I started and 180  
when I finished, so it still doesn't actually prove or disprove (to  
me) what Tom was saying when he recommended doing this to achieve 202  
degrees for brewing. It is physically impossible for me to get water  
to that temperature without it boiling. When it was at that  
temperature and I removed it from the heat source, it dropped to the  
upper 180's within 30 seconds. The coffee tasted the same to me as  
what comes out of my Bunn.
I'd be interested in seeing how the Technivorm reacts in my  
elevation. Anyone interested and willing to depart with it for a few  
days, and willing to pay the postage to get it to me, just let me  
know and we'll make arrangements. I'll pay to have it shipped back.  
Or if someone has one and lives in a high elevation (3700+ feet) let  
me know how it handles the temperature and I'll post the info here.
--
Walter R Basil
www.basilweb.net

2) From: Peter Zulkowski
Hmmmm...
and the answer is???
cowboy coffee in a pressure cooker!
Brew at the correct pressure to achieve the required temperature for the 
correct amount of time...
Dump into a french press to extract the grounds, or pour through a 
filter. :)
PeterZ
Who cranked his Bunn (commercial version) up so the water goes into the 
filter at ~ 195F, here in LHC,  just a few hundred feet above sea level..
Walter R. Basil wrote:
<Snip>

3) From: Rick Copple
Walter R. Basil wrote:
<Snip>
Hi Walter,
Interesting thoughts. There may be a point as to whether someone up at 
high elevations can get the water to the proper temp without it boiling 
away. Not sure how a Presto or Tech. would do up there in that regard. 
My guess is it would still get it to the right temp, as 195 is still 
below the boiling point there even though it is bubbling. I think it is 
bubbling quite a bit down here in the lower altitudes to. Not sure 
whether that would keep the water from coming out.
I think the issue on the temp in relation to good brew is primarily at 
what temp the water is at when it first hits the grinds. Certainly it 
will get lower as it goes through, etc. However, I think what has been 
generally discovered is if your pot heats the water up to around 195 
degrees when the water hits the grounds, that it is going to extract a 
much better flavor than if it is in the 180s or below. I could tell a 
difference when I started brewing in my Presto. It even has a heating 
element right where the water comes out to fall into the grounds.
Everywhere else, you just want it hot, like down in the pot, etc. 180 is 
probably fine for the pot itself.
I wouldn't say a coffee pot that was at 185 is defective (that would 
indicate an unintentional design flaw, but they do that on purpose), it 
just doesn't get all the flavor out of the bean that it could.
I understand that most all coffee makers use to be around 195 or so, but 
after McDonalds was sued by the lady who spilled coffee on herself and 
was burned, and won the suit, everyone cranked their pots down so they 
wouldn't get sued when someone spills coffee on them and blames it on 
the machine that it was hot.
-- 
Rick Copple
Marble Falls, TXhttp://blog.copple.us/?sectionid=5

4) From: Walter R. Basil
It sounds as though you were lucky enough to get that temperature.  
Congratulations! I read about people being able to adjust their temp  
in the commercial versions. Unfortunately, for the reasons stated in  
my blog, it would appear to be allusive to me, even in a commercial  
version; unless I was willing to have my water at a light boil all  
the time ;-)
As for the cowboy coffee - ugh! I'll pass. I'll still enjoy it the  
way I've been.  I think that would fall under "special efforts" in my  
opinion.
On Jan 25, 2006, at 11:03 PM, Peter Zulkowski wrote:
<Snip>
--
Walter R Basil
www.basilweb.net

5) From: Walter R. Basil
On Jan 26, 2006, at 10:20 AM, Rick Copple wrote:
I wasn't trying to disagree with the perfect temperature, just the  
fact that some people won't be able to get that temperature. As  
always, the "good" coffee is in the mouth of the taster too. I take  
everyone's word for it that 195 is the best temperature, because,  
well, I can't do it without having the water boiling, and I'm not  
about to brew coffee with boiling water when I want my coffee. The  
point of my experiment was to show that one has to go through  
extraordinary lengths in some locations to attain that temperature. I  
just make too much coffee to do that. A pot in the morning when I get  
up, a pot when I get to work, a pot at work after lunch, and a pot at  
home after dinner. For special occasions perhaps I'd go through the  
trouble. Heck, I have this thing my mom gave me that she refferred to  
as "the Tin Man" that brews about a cup of coffee by heating up the  
water and I assume it builds up enough pressure inside that the steam  
forces the water through to the top of the Tin Man. That could  
probably do it, I'm sure. Again, more trouble than it's worth for the  
amount of coffee I drink. ;-)
Happy drinking!
-Walt
<Snip>
--
Walter R Basil
www.basilweb.net

6) From: Alchemist John
hrm, kind of sounds like espresso to me...
Elevated pressure, "correct" temperature.
I wonder what the KMB brewing temperature is?
At 20:12 1/25/2006, you wrote:
<Snip>
John Nanci
AlChemist at large
Zen Roasting , Blending & Espresso pulling by Gestalthttp://www.chocolatealchemy.com/

7) From: Chuck the Coffee-Geek
First thing I did when it arrived was brew a pot while my steaming 
thermometer was in the pot.
The temp in the pot when it was finished was 194F.  Thats the reason I 
was so excited about this coffee maker.
-Chuck
Still in love with the KMB
Alchemist John wrote:
<Snip>

8) From: Rick Copple
Walter R. Basil wrote:
<Snip>
I'm just wondering Walter, maybe it doesn't matter at what temp the 
water bubbles (boils) but what the temperature itself is. IOW, the 
standard temp to boil, I guess being 212, drops down to, let's 
speculate, 190 at a certain altitude...the temperature is still the 
same. So it seems to me that even if the water is "boiling" away like 
crazy, as long as it is 195 and not 212, you are still fine and it 
should taste better. Temp is what makes the diff, not at what temp the 
water boils. At least, that makes sense to me...but I haven't run 
scientific labratory test on it to ensure repeatable performance and 
test this hypothesis.
Will get right to work coming up with the government grant to do that 
study! ;-) Right after I get the one for testing how motorcyclist feel 
when riding next to 18 wheelers.
-- 
Rick Copple
Marble Falls, TXhttp://blog.copple.us/?sectionid=5


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