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Topic: screening ground coffee (18 msgs / 299 lines)
1) From: jim gundlach
I'm home alone so instead of cleaning the house early this evening I 
played around with developing a screening protocol.   I bought a 
graduated ten ml cylinder and worked on being consistent in actually 
screening the coffee and measuring.  I have several samples from the 
Solis Maestro so I can give it a good evaluation along with the Rocky 
of course.  Someone offered to send some mazer samples but I don't have 
them yet.  After experimentation I have decided on a two stage 
analysis.  The first is a dust analysis.  For this I will measure ten 
ml of ground coffee and put in the #60 screen.  I will throughly screen 
and measure the dust collected from that that one sample.  The second 
analysis will not worry about the dust, but will be a traditional 
screening that measures the volume of coffee captured by each screen 
starting with the coarsest, #12, and continue down through the finest, 
#60.  Since I now have the size of the holes calculated I can now 
calculate the standard deviation as an appropriate measure of 
distribution.  One inconsistency I have so far is that once screened 
the coffees add up to more than the ten ml that I started out with.  
For example, one coarse Maestro sample I ran ended up with 12.1 
screened sample totals when I started with 10 ml to begin with.  Some 
of this is probably more compaction going on with the single tall 
column of coffee but some of it is small grains fitting in empty spaces 
around the large grains when the sample is not screened but not being 
able to when it is.
I just realized that this problem means I should use weights not 
volumes.  Guess I will have to wait until I get a scale.
Jim Gundlach
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2) From: sho2go
I'm going to send an Innova sample along shortly.  Wanted to wait until
after the Christmas rush.
Mike

3) From: Simpson
I'm still waiting for new burrs for the Major. I'll send Major, Super Jolly
and Mahlkoenig Kenia samples then.
Also, yes you will need a scale and I need to know what grind size you are
looking for.
*********** REPLY SEPARATOR  ***********
On 12/28/2002 at 8:58 PM jim gundlach wrote:
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4) From: jim gundlach
On Saturday, December 28, 2002, at 10:24 PM, Simpson wrote:
<Snip>
I'm seeing major differences between a coarse, aka french press or 
drip, and fine, espresso, grinds so if you can send a sample of each 
grind for each machine.  If you want to see how much improvement the 
new burrs made, you could include samples from the old burrs as well.
     Jim Gundlach
<Snip>
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5) From: Rick Farris
Jim wrote:
<Snip>
And in the interest of economy and of utility, I would use rather large
samples: 100g, if not 1000g!  As to scales, have you looked at the My Weigh
i600?
-- Rick
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6) From: jim gundlach
The samples I have been working with are probably in the neighborhood 
of 5 grams.  I thought they were a little small so when I move to 
weight I will probably move up to 10 gram samples and I will need a 
scale that will measure tenths of a gram.
  I will look into the My Weight i600, I have never heard of it.  Cost 
is a deciding factor, I'm trying to see how economical I can make this 
system.  Of course some nice scales would have other uses.
jim gundlach
On Sunday, December 29, 2002, at 12:20 AM, Rick Farris wrote:
<Snip>
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7) From: Dan Bollinger
Here's how Illy does it:http://patft.uspto.gov/netacgi/nph-Parser?Sect1O2&Sect2TOFF&p=1&u=/netahtml/search-bool.html&r=6&f=G&lP&co1
D&d=ft95&s1=coffee.ABST.&s2=grinde
r.ABST.&OS«ST/coffee+AND+ABST/grinder&RS«ST/coffee+AND+ABST/grinder

8) From: jim gundlach
Dan,
    From the description:
"The system of the invention includes improvements which include a  
first device which continually receives undisturbed ground coffee  
samples and delivers these samples to a second device in which a gas  
stream blows a stream of coffee grains down a tube to the test-meter  
and a second stream of gas flowing at right-angles to the tube  
disperses any partially aggregated particles before they reach the  
test-meter. A third device creates a pressurized safety area around  
each lens of the laser test-meter. The area is partly closed so that  
laser beams can freely pass, and gas under pressure enters the area  
preventing coffee grains from entering the area and disturbing the  
lens. A fourth device sucks the grains from the test area and delivers  
them into an eddy-chamber from which they are periodically transferred  
to the system for conveying ground coffee to the packing machinery."
I think that would break the $35.00 budget I had in mind for the  
project.
I just ordered an analog My Weight scale that should do the job.  It  
cost about $15.00 including shipping.  I know digital would be better  
but this keeps me on the cheap side and I should be able to get all the  
samples I have analyzed by the end of January.  I also though I would  
try screening a filter full for precise same size grains just to see  
what it tastes like.
    Jim Gundlach
On Tuesday, December 31, 2002, at 07:17 AM, Dan Bollinger wrote:
<Snip>
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9) From: Dan Bollinger
LOL!  You couldn't touch if for $3500 let alone $35.  :)   After you've
finished with your screening, why not test some Illy ground espresso, too?
Dan

10) From: jim gundlach
On Tuesday, December 31, 2002, at 09:05 PM, Dan Bollinger wrote:
<Snip>
Good idea.  Anybody got any stale Illy stashed that they would be 
willing to send?
Jim Gundlach
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11) From: Steve Wall
On Tuesday, December 31, 2002, at 09:42 PM, jim gundlach wrote:
<Snip>
I have some.  I could also run some coffee through a Zassenhaus if 
you're interested.
Has anyone submitted any box grinder espresso?
Steve Wall
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12) From: AlChemist John
Sometime around 19:02 12/31/02, jim gundlach typed:
<Snip>
Here I thought that was part of the reason for making the screens.  To see 
if  removing all dust and course particles improved the cup.  Maybe a 
simple way to "help" a whirly blade or aging burr.
--
John Nanci 
AlChemist at large
Roasting and Blending by Gestalt
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13) From: Angelo
Jim,
I was wondering if you could test fresh roast vs. stale of the same 
batch....It seems as the beans get older, one needs to change the settings 
on a grinder...
Thanks,
Angelo
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14) From: jim gundlach
Steve,
     Yes, I've already got some Zass samples.  And Fulton Martin has 
just offered to send some Illy.
Thanks anyway.
Jim Gundlach
On Wednesday, January 1, 2003, at 08:09 AM, Steve Wall wrote:
<Snip>
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15) From: jim gundlach
On Wednesday, January 1, 2003, at 09:10 AM, AlChemist John wrote:
<Snip>
That is what I had in mind at first but I've found that with the Rocky 
there is some variability in grain size and that it produces a 
distribution that is close together and has little variability compared 
to a couple of others I've looked at.  However, it does not all filter 
to one screen.  That is, in so far as I have the ability to measure 
grain size, the Rocky does not produce the ideal of every piece of 
ground coffee being exactly the same size.  With screens it is possible 
to reduce variability further.  I thought that since I can do it, why 
not?
Jim Gundlach
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16) From: jim gundlach
Ah?
     I don't think I really want a stale bean to touch the Rocky.
          Jim Gundlach
On Wednesday, January 1, 2003, at 09:51 AM, Angelo wrote:
<Snip>
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17) From: Dan Bollinger
With all due respect, Angelo, I'm not excited about improving the quality of
stale beans, better to toss them are roast some fresh ones.  Although,
Folger's might be interested in this research.  ;)  Dan
<Snip>
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18) From: Angelo
I was not concerned about improving the quality of stale beans. I was 
curious to see whether  the grinds get larger over time due to possibly 
picking up moisture from the air...I do notice that as the beans age(even 
within the range of freshness) the grinder settings need to be adjusted to 
maintain the same flow rate....
The beans could be run through fresh, one group screened immediately. The 
other group could be screened a few days later....
What this has to do with Folgers is a bit beyond me...:-)
Ciao,
Angelo
<Snip>
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