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Topic: Bloom and Crema - Chemists Out There? (12 msgs / 501 lines)
1) From: David T. Borton
This is a multi-part message in MIME format.
All,
When I use the press pot, I get a wonderful bloom.  Often, it seems that 
the fresher the coffee, the greater/taller the bloom.  Chemically, what 
is bloom?  Is it merely more carbon dioxide getting released?
And while we are at it, while I am not an espresso-type, what about 
/crema/?  Same chemical process occurring here or a whole different 
kettle of fish (beans)?
Anyone know definitively?  I have asked around and many have theories 
but no one says, "You can take this to the bank...."
DB
-- 
The breezes taste
          Of apple peel.
The air is full
                Of smells to feel-
                  Ripe fruit, old footballs,
              Burning brush,
              New books, erasers,
                 Chalk, and such.
        The bee, his hive,
                      Well-honeyed hum,
       And Mother cuts
                     Chrysanthemums.
                       Like plates washed clean
                        With suds, the days
        Are polished with
                   A morning haze.  ~ John Updike

2) From: Steve Hay
On 9/9/06, David T. Borton  wrote:
<Snip>
From Wikipedia: Crema is a reddish-brown foam which floats on the surface of
the espresso. It is composed of vegetable
oils,
proteins  and
sugars.
Crema has elements of both emulsion and
foam 
colloid
.
Theory: I think bloom is similar to crema chemically but different
physically.  Specifically, I'm guessing that the oils/protein that make up
crema aren't mixed up in as much when bloom occurs.  I've wondered and go
back and forth about whether bloom is mostly protein or mostly oil.  I
should probably read my "On Food and Cooking" book again which has some
pretty good chemical descriptions of various foams...
-- 
Steven Hay
hay.steve -AT- gmail.com
Barry Paradox: Consider k to be the greatest element of the set of natural
numbers whose description require maximum of 50 words: "(k+1) is a natural
number which requires more than 50 words to describe it."

3) From: Leo Zick
This is a multi-part message in MIME format.
i believe crema is co2 coming out of the extracted bean (grind).
im sure there are proteins and oils mixed in as well  
From: Steve Hay [mailto:hay.steve] 
Sent: Saturday, September 09, 2006 11:34 AM
To: homeroast
Subject: Re: +Bloom and Crema - Chemists Out There?
On 9/9/06, David T. Borton  wrote: 
All,
When I use the press pot, I get a wonderful bloom.  Often, it seems that the
fresher the coffee, the greater/taller the bloom.  Chemically, what is
bloom?  Is it merely more carbon dioxide getting released?
And while we are at it, while I am not an espresso-type, what about crema?
Same chemical process occurring here or a whole different kettle of fish
(beans)?
Anyone know definitively?  I have asked around and many have theories but no
one says, "You can take this to the bank...."
From Wikipedia: Crema is a reddish-brown foam which floats on the surface of
the espresso. It is composed of vegetable oils
 , proteins
  and sugars
 . Crema has elements of both emulsion
  and foam
  colloid
 .
Theory: I think bloom is similar to crema chemically but different
physically.  Specifically, I'm guessing that the oils/protein that make up
crema aren't mixed up in as much when bloom occurs.  I've wondered and go
back and forth about whether bloom is mostly protein or mostly oil.  I
should probably read my "On Food and Cooking" book again which has some
pretty good chemical descriptions of various foams... 
-- 
Steven Hay
hay.steve -AT- gmail.com
Barry Paradox: Consider k to be the greatest element of the set of natural
numbers whose description require maximum of 50 words: "(k+1) is a natural
number which requires more than 50 words to describe it." 

4) From: miKe mcKoffee
CO2 bloom and espresso crema are very different animals. One being a
fleeting mass of bubbles while the other being the essence of the
pressurized extraction. Here's an article by David Schomer which includes
some discussion of espresso crema.http://www.lucidcafe.com/cafeforum/schomertable16.htmlKona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipes etc:http://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.
	From: homeroast-admin
[mailto:homeroast-admin] On Behalf Of David T. Borton
	Sent: Saturday, September 09, 2006 8:10 AM
<Snip>
	When I use the press pot, I get a wonderful bloom.  Often, it seems
that the fresher the coffee, the greater/taller the bloom.  Chemically, what
is bloom?  Is it merely more carbon dioxide getting released?
	
	And while we are at it, while I am not an espresso-type, what about
crema?  Same chemical process occurring here or a whole different kettle of
fish (beans)?
	
	Anyone know definitively?  I have asked around and many have
theories but no one says, "You can take this to the bank...."
	
	DB
<Snip>

5) From: Sandy Andina
--Apple-Mail-77--873670136
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Crema is an unstable emulsion of water and coffee oils, with CO2 as  
the "binder." As the CO2 escapes, the emulsion breaks down.
On Sep 9, 2006, at 11:45 AM, miKe mcKoffee wrote:
<Snip>
Sandy
www.sandyandina.com
--Apple-Mail-77--873670136
Content-Transfer-Encoding: quoted-printable
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Crema is an unstable emulsion of =
water and coffee oils, with CO2 as the "binder." As the CO2 escapes, the =
emulsion breaks down.
On Sep 9, 2006, at 11:45 AM, miKe =
mcKoffee wrote:
CO2 bloom and espresso crema are = very different animals. One being afleeting mass = of bubbles while the other being the essence of thepressurized extraction. Here's an article by David = Schomer which includessome discussion of espresso = crema.http://www=.lucidcafe.com/cafeforum/schomertable16.html Kona = Konnaisseur miKe mcKoffeeURL to Rosto = mods, FrankenFormer, some recipes etc:http://mdmint=.home.comcast.net/coffee/Rosto_mod.htmfirst not know. And in knowing = know I know not. Each Personal enlightenmentfound exploring the many divergent foot steps of = Those who have gone before. From: homeroast-admin= s.sweetmarias.com[mailto:homeroast-adm= in] On Behalf Of David T. Borton Sent: Saturday, September 09, = 2006 8:10 AM


When I use the press pot, I get a = wonderful bloom.  Often, = it seemsthat the fresher the coffee, the = greater/taller the bloom.  = Chemically, whatis = bloom?  Is it merely more = carbon dioxide getting released?


And while = we are at it, while I am not an espresso-type, what aboutcrema?  = Same chemical process occurring here or a whole different kettle = offish (beans)?


Anyone = know definitively?  I = have asked around and many havetheories but = no one says, "You can take this to the bank...."


DB = = homeroast mailing listhttp://li=sts.sweetmarias.com/mailman/listinfo/homeroastTo change your personal list settings (digest = options, vacations, unsvbscribes) go to http://=sweetmarias.com/maillistinfo.html#personalsettings = = --Apple-Mail-77--873670136--

6) From: David Springston
This is a multi-part message in MIME format.
There is a good article in the September/October issue of Roast magazine =
on creating crema:  Creating Crema with Single-Estate Coffees.
David

7) From: miKe mcKoffee
Interesting article titled "Crema of the Crop: Creating Crema with
Single-Estate Coffees" in the September/October Roast Magazine that came
yesterday. Unfortunately this article is not available online.
Excerpt:
"But what is crema exaclty? According to the scientists, crema consists of a
complex solution of polyphasic foam colloids (a mixture with properties
between those of a solution and fine suspension, similar to, say, butter or
asphalt) and emulsions (a mixture of two unmixable substances), which carry
the aroma. Crema is chemically complex and volatile with many of its
chemical components degrading from oxidation or loss of temperature. In
common terms, crema is composed of oils, proteins and sugars."
"Dr. Joseph John, president of Josuma Coffee Co., describes crema as 'tiny
bubbles containing the vapors released by the ground coffee particles during
the extraction process. These vapors contain the aroma molecules responsible
for the flavor sensation experienced while drinking espresso. Much of that
flavor comes more from the aroma sensation in the nose than from the taste
sensation in the mouth. The role of crema is to capture that aroma and
deliver it to the nose.'"
"John goes on to say, 'We drink coffee purely for the pleasure of drinking
it. There is no intrinsic mechanism in brewed coffee to capture the aroma of
coffee. Crema is the mechanism in espresso to capture the aroma and deliver
it to the nose of the consumer.'"
Later in the article:
"As we look at the results, a distinction between crema and foam needs to be
made. Foam is formed when the coffee is too fresh and copious amounts of
carbon dioxide coming out of the ground coffee prevents any water from
getting in and extracting flavors. The foam is a collection of bubbles with
a film of water on the outside and carbon dioxide inside and very little
flavor molecules. This foam will dissipate in no time at all. We want to
isolate crema, a collection of bubbles with oil layers on the outside and
flavor molecules on the inside, which tend to last a long time..."
End of my typing article excerpts!!! Way more interesting and educational
stuff but you'll have to get the mag' yourself:-)
As can be seen foam as created from releasing CO2 (like via press pot) is
very different animal from crema. Foam being bubbles surrounded by water on
the outside and carbon dioxide on the inside, crema bubbles surrounded by
coffee oils on the outside and flavor molecules on the inside. Only espresso
extraction with pressures in the 9bar range are capable of creating the
highly desirable and aromatically essential crema. This may be why for even
a "cup of coffee" I much prefer an Americano from a properly pulled shot to
other forms of brewing, more flavor.
Next Gathering I host maybe we'll have a specific session comparing the same
coffee press pot and/or vac to Americano for the non-believers to taste for
themselves... It will however not be until next year some time since hosted
two in the last three months. 
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipes etc:http://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.
<Snip>
[mailto:homeroast-admin] On Behalf Of David T. Borton
	Sent: Saturday, September 09, 2006 8:10 AM
<Snip>
	All,
	
	When I use the press pot, I get a wonderful bloom.  Often, it seems
that the fresher the coffee, the greater/taller the bloom.  Chemically, what
is bloom?  Is it merely more carbon dioxide getting released?
	
	And while we are at it, while I am not an espresso-type, what about
crema?  Same chemical process occurring here or a whole different kettle of
fish (beans)?
	
	Anyone know definitively?  I have asked around and many have
theories but no one says, "You can take this to the bank...."
	
	DB
<Snip>

8) From: Ed Needham
Speaking of frothy things on top of coffee...
I started a fermented coffee today.  This is just an experiment to see what 
I might need to do to make a real batch of the stuff.
Strongly brewed coffee, a bunch of corn sugar, and ale yeast.  We'll see 
what transpires in a few days.
*********************
Ed Needham®
"to absurdity and beyond!"
ed at homeroaster dot com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************

9) From: Andy Thomas
I'm looking forward to hearing about the results, Ed.
Did you start with a formula of any kind, regarding
ratio of coffee/corn sugar/yeast? What alcohol
concentration are you shooting for? Do you plan to
leave any residual sugar? Sounds like it could be
either awesome or awful. Good luck.
Andy
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10) From: Ed Needham
This is just a trial balloon.  I tried to find if anyone else out there had 
done a ferment of just brewed coffee, and I was surprised to find little of 
nothing.  Maybe if I refine my search terms I can find more than the three 
or four attempts at a fermented coffee besides Nestlé's latest 
beer-coffee-caffeine product.
I'm guessing that I'll have to kill the yeast at the end of a short ferment, 
and then add back some sweetness.
Maybe I'll keep the yeast and add a little priming sugar and bottle 
carbonate it.
(it's getting weird in here--somebody stop me!)
*********************
Ed Needham®
"to absurdity and beyond!"
ed at homeroaster dot com
(include [FRIEND] in subject line to get through my SPAM filters)
*********************

11) From: Alchemist John
weird, I haven't noticed anything weird.  Can't 
be sure about that until I taste it thought ;)
I like the idea of carbonating.  I wouldn't worry 
that it is not sweet, although a little invert sugar might take care of=
 that.
At 22:14 9/9/2006, you wrote:
<Snip>
John Nanci
AlChemist at large
Zen Roasting , Blending & Espresso pulling by Gestalthttp://www.chocolatealchemy.com/

12) From: Justin Marquez
On 9/9/06, Sandy Andina  wrote:
<Snip>
Clear and concise description, Sandy!  Well done.
Safe Journeys and Sweet Music
Justin Marquez (Snyder, TX)


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