[Homeroast] Definitions and Agtron > hazmat blends of *$

Joseph Robertson theotherjo at gmail.com
Tue Mar 9 12:17:25 CST 2010


Tom,
Since you asked I contacted Mane' Alves my roasting instructor and posed
your question to him. He uses the Agtron on a daily basis and is very
familiar with this science and I think knows you. You may have met on coffee
farm travels.
Here is his response to our discussion of the Agtron and it's possible
alternatives. He said I could share his comment with our list.

  "Coffee, the roasted kind is very difficult to measure color wise.
The reason, like Tom mentioned at one point, the roughness of the ground and
the reflectance/refraction of the bean itself defeats most of the methods
one could use visually (painters use Pantone color chips, it doesn’t work
here).

Agtron it was originally built to measure ground coffee, but it does a very
good job in measuring whole bean as well. These measurements will not
determine roast profiles, but there are patterns that emerge when you have
an Agtron and measure over time.
For instance if the inside and out of the same bean is more than 10 Agtron
points apart, most likely you have a problem with the roast (too roasted on
the outside and un-roasted on the inside); the same goes for too small of
differences from the outside in. When these numbers are close (the same in
and out or 1 or 2 points difference) in general the coffee is flat on the
cup.

So although the Agtron does not define profiles it will indicate the
tendencies in some roasts.

Are there alternatives in the market? Of course, Javalitics and Colortrack
just to name a few. These machines are less than half the price of the least
expensive Agtron and do a very good job in measuring color.

I tried to measure coffee with different systems originally designed to
measure color (BYK-Gardner and Konica-Minolta) and the results were less
good and repeatable. "

Hope this helps.

Best regards,

Mane' Alves
Coffee Lab International
(802) 244-6176

On Mon, Mar 8, 2010 at 4:36 PM, Tom & Maria - Sweet Maria's Coffee <
sweetmarias at sweetmarias.com> wrote:

> I just still can't believe there is not a simple optical scanner system
> that could be used on coffee. For graphic designers there is a vast array of
> cheap devices to analyze color. I am sure surface texture and reflectance is
> an issue. But how hard can it be? I think there should be a $150 scanner
> that would work on coffee.
> --
> -Tom
>
>
> ____________________________________________________________________________
> "Great coffee comes from little roasters" - Sweet Maria's Home Coffee
> Roasting
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Ambassador for Specialty Coffee and palate reform.


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