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Date: 18 Apr 2007 08:16:37
From: TedJ
Subject: Is oil a good thing?
I posted this on CG but got little response, so I'll try here.

I usually roast into 2nd Crack, with the results that the beans take
on a sattony sheen, but no surface oils. Within a couple of day the
beans are spotted with oil, some varieties more than others.

I have two questions; first, what is the mechanism that transports the
oils to the surface of the bean two or even three days after roasting?
Is it the escaping gas which carries the oils or, as has been
suggested, is it that the structure of the bean has broken down
allowing the oils to simply migrate to the surface? Second question;
what is the composition of the oil? Is it primarily sugar and caffeine
or are there other essences of the coffee flavor? Are these surface
oils something that we would rather not include when brewing our
coffee, or are they something we should savor?

I'm thinking of experimenting with removing these oils (beans on a
paper towel) and seeing if I can detect any difference in the brewed
coffee. Has anyone else done this?

Thanks for you help.

Ted J





 
Date: 01 Jun 2007 19:20:33
From: Harold Finkle
Subject: Re: Is oil a good thing?
Hi Ted,

You raise an excellent question about the oils, and although you've had
several responses to your questions, I disagree with a few so I thought
I'd write as well.

If you are roasting into second crack then definitely expect sheen when
finished roasting and definitely expect oils to comeout. THESE OILS ARE
GOOD! YOU WANT THEM!! =)

Here is what's happening that transports oils to the surface:
when the bean is green there is moisture present with the natural sugars
and oils. The moisture heats up and caramelizes the sugars. Because
oil and water doesn't mix it pushes the oil out as it tries to escape.
It does escape, and these are the cracks you hear.

The chemical processes taking place within the bean as it roasts are
complex. But more importantly, the processes don't stop when you finish
roasting. It is common to hear 'cracks and pops' up to a week past
roasting as gases continue to escape through weak spots in the beans.
As such, these gases continue to push out oils. the darker you roast a
coffee, the more weak spots it has, and the more places oils have to
escape. This

Another poster recommended using 'air tight' containers. DO NOT DO THIS!
I've seen many a bag, bottle, can, container explode because of the
gases that escape after roasting. Instead, use containers with one way
degassing valves. This keeps the coffee fresh but lets built up gasses
escape.

The oil is good for this reason - it contains flavor, and it gives
coffee body. If you want to fully experience a dark roasted coffee, use
a french press to prepare it. If you want to remove some of the oil,
don't use a papertowl as you suggested. it will impart a bad flavor to
the beans. Instead use a drip coffee brewer. the filter will soak up
the oils. Double the filter if you want more oil removed.

To answer your question about coffee contents, there are more than 40
different chemicals present naturally in the beans that all make up its
distinct flavor profile, and you don't want to remove any of them.

Enjoy roasting and ask more!

Harry

http://www.baristaforum.com
Learning about coffee? Join the discussion at baristaforum.com





TedJ wrote:
> I posted this on CG but got little response, so I'll try here.
>
> I usually roast into 2nd Crack, with the results that the beans take
> on a sattony sheen, but no surface oils. Within a couple of day the
> beans are spotted with oil, some varieties more than others.
>
> I have two questions; first, what is the mechanism that transports the
> oils to the surface of the bean two or even three days after roasting?
> Is it the escaping gas which carries the oils or, as has been
> suggested, is it that the structure of the bean has broken down
> allowing the oils to simply migrate to the surface? Second question;
> what is the composition of the oil? Is it primarily sugar and caffeine
> or are there other essences of the coffee flavor? Are these surface
> oils something that we would rather not include when brewing our
> coffee, or are they something we should savor?
>
> I'm thinking of experimenting with removing these oils (beans on a
> paper towel) and seeing if I can detect any difference in the brewed
> coffee. Has anyone else done this?
>
> Thanks for you help.
>
> Ted J
>


  
Date: 02 Jun 2007 18:46:48
From: Scott Sellers
Subject: Re: Is oil a good thing?
Harold Finkle <bluebaby92877@hotmail.com >:
[...]
>Another poster recommended using 'air tight' containers. DO NOT
>DO THIS! I've seen many a bag, bottle, can, container explode
>because of the gases that escape after roasting. Instead, use
>containers with one way degassing valves. This keeps the coffee
>fresh but lets built up gasses escape.

I use mason canning jars with band/dome lids. I leave the lids
cracked for the first day or two after roasting, then seal them
after that. I like that "swoosh" sound and intense roast coffee
aroma hit when I open the lids.

What I've never understood is vacuum packed coffee. How can
there be fresh roasted coffee without out-gassing?

cheers,
Scott S

--
Scott Sellers


  
Date: 02 Jun 2007 13:23:09
From: Steve Ackman
Subject: Re: Is oil a good thing?
In <%L18i.17340$px2.6007@bignews4.bellsouth.net >, on Fri, 01 Jun 2007
19:20:33 -0400, Harold Finkle wrote:

> there are more than 40 different chemicals present
> naturally in the beans that all make up its distinct
> flavor profile,

Multiply that number by 20 and you're in the ballpark.
Depending on who you read, the number of flavor
compounds in coffee ranges from a low of about 750 to
some authors claiming in excess of 900.
(Wine contains around 150.)


 
Date: 20 Apr 2007 23:01:20
From: diab0lus
Subject: Re: Is oil a good thing?
On Apr 20, 3:28 pm, TedJ <theojo...@charter.net > wrote:
> I'm roasting primarily for espresso, but also for French Press. I
> don't want to remove the oils if they impart a signficant flavor, but
> if the oils are more likely to add bitterness, then I may try to get
> rid of it. It should be pretty easy for me; I weigh out 16g of coffee
> per double, so 'll just pour them onto a paper towel at dab a bit
> befor grinding.

I just saw the TC thread where you stated that you use a Hottop. I
have one also. What settings are you using? Do you run it on a
variac?

Last reply to your post, I promise.

Ryan




 
Date: 20 Apr 2007 22:56:01
From: diab0lus
Subject: Re: Is oil a good thing?
On Apr 20, 3:28 pm, TedJ <theojo...@charter.net > wrote:
> I'm roasting primarily for espresso, but also for French Press. I
> don't want to remove the oils if they impart a signficant flavor, but
> if the oils are more likely to add bitterness, then I may try to get
> rid of it. It should be pretty easy for me; I weigh out 16g of coffee
> per double, so 'll just pour them onto a paper towel at dab a bit
> befor grinding.

If taking a picture is too much to ask, how about picking a number
from a chart? I shoot for number 12 (Full City+) or 13 (Vienna) in
this picture when I roast.

http://sweetmarias.com/roastprocess-singlebean/roasting-allin1.jpg

Referring page:

http://sweetmarias.com/roasting-VisualGuideV2.html

What beans are you using?

Ryan




 
Date: 20 Apr 2007 22:45:15
From: diab0lus
Subject: Re: Is oil a good thing?
On Apr 20, 3:28 pm, TedJ <theojo...@charter.net > wrote:
> I'm roasting primarily for espresso, but also for French Press. I
> don't want to remove the oils if they impart a signficant flavor, but
> if the oils are more likely to add bitterness, then I may try to get
> rid of it. It should be pretty easy for me; I weigh out 16g of coffee
> per double, so 'll just pour them onto a paper towel at dab a bit
> befor grinding.

When oil is burnt onto the outside of a burnt bean the coffee starts
to taste like... umm, burning, charcoal, ash, a well done steak
without the steak. Obviously do whatever works for you, but if you
roast light enough so oil doesn't get all over the place then you can
enjoy the bean, sugars, oils, everything in the cup before
carbonization occurs.

Try this: Take one of your beans and put it in your mouth. What does
it taste like? Chew it up. It shouldn't be repulsive.

I am curious to actually see the roast level you are getting. Could
you take a picture of your roasted coffee and post a link to it? Take
the picture in a well lit area so the roast level can be seen.

Ryan



 
Date: 20 Apr 2007 18:52:20
From: Flasherly
Subject: Re: Is oil a good thing?
On Apr 20, 3:28 pm, TedJ <theojo...@charter.net > wrote:
> On Apr 19, 9:44 pm, diab0lus <r0cketscient...@hotmail.com> wrote:
>
>
>
> > On Apr 18, 11:16 am, TedJ <theojo...@charter.net> wrote:
>
> > > I posted this on CG but got little response, so I'll try here.
>
> > > I usually roast into 2nd Crack, with the results that the beans take
> > > on a sattony sheen, but no surface oils. Within a couple of day the
> > > beans are spotted with oil, some varieties more than others.
>
> > Depending on what blend or SO I am roasting for espresso, I normally
> > roast until the first snap of second, a few snaps into second or,
> > rarely, start of rolling second. I haven't found desirable tastes
> > beyond that for espresso. A few nights ago I was roasting while the
> > sun was going down, the lighting changed (I roast outside) and I
> > roasted a batch too dark. I guess the smoke wasn't enough of an
> > indicator for me. The shot I pulled today tasted ashy with hardly any
> > origin characteristics. It was unpleasant. I had also roasted a
> > batch of the same blend to the first snap or five of second crack and
> > it was great. I haven't found any compelling reason to intentionally
> > roast so dark that oil covers the beans after resting, but maybe that
> > is your preference. Try roasting lighter, see if you like it. If you
> > do, try roasting even lighter. Great shots can be had without going
> > into second crack.
>
> > > I'm thinking of experimenting with removing these oils (beans on a
> > > paper towel) and seeing if I can detect any difference in the brewed
> > > coffee. Has anyone else done this?
>
> > I haven't, but the oily mess is annoying. You know, I assumed that
> > you were drinking espresso when I wrote above. What brew method(s) do
> > you use?
>
> > Ryan
>
> I'm roasting primarily for espresso, but also for French Press. I
> don't want to remove the oils if they impart a signficant flavor, but
> if the oils are more likely to add bitterness, then I may try to get
> rid of it. It should be pretty easy for me; I weigh out 16g of coffee
> per double, so 'll just pour them onto a paper towel at dab a bit
> befor grinding.


Doesn't sound right. Oily, black, smoked and burnt, is part of French
roasting - not well regarded in coffee tastes for most. Past espresso
roasting. (I've acceptable quantity for taste slightly into the first
crack on a pound an hr. . .but don't have enough control, a good
enough roaster to profile espresso roasts).

The oils are caramelized sugar, as are coffee oils, essence of coffee
tastes. Wiping down roasted coffee beans is not part of the process.
It's a no-no.



 
Date: 20 Apr 2007 12:28:24
From: TedJ
Subject: Re: Is oil a good thing?
On Apr 19, 9:44 pm, diab0lus <r0cketscient...@hotmail.com > wrote:
> On Apr 18, 11:16 am, TedJ <theojo...@charter.net> wrote:
>
> > I posted this on CG but got little response, so I'll try here.
>
> > I usually roast into 2nd Crack, with the results that the beans take
> > on a sattony sheen, but no surface oils. Within a couple of day the
> > beans are spotted with oil, some varieties more than others.
>
> Depending on what blend or SO I am roasting for espresso, I normally
> roast until the first snap of second, a few snaps into second or,
> rarely, start of rolling second. I haven't found desirable tastes
> beyond that for espresso. A few nights ago I was roasting while the
> sun was going down, the lighting changed (I roast outside) and I
> roasted a batch too dark. I guess the smoke wasn't enough of an
> indicator for me. The shot I pulled today tasted ashy with hardly any
> origin characteristics. It was unpleasant. I had also roasted a
> batch of the same blend to the first snap or five of second crack and
> it was great. I haven't found any compelling reason to intentionally
> roast so dark that oil covers the beans after resting, but maybe that
> is your preference. Try roasting lighter, see if you like it. If you
> do, try roasting even lighter. Great shots can be had without going
> into second crack.
>
> > I'm thinking of experimenting with removing these oils (beans on a
> > paper towel) and seeing if I can detect any difference in the brewed
> > coffee. Has anyone else done this?
>
> I haven't, but the oily mess is annoying. You know, I assumed that
> you were drinking espresso when I wrote above. What brew method(s) do
> you use?
>
> Ryan

I'm roasting primarily for espresso, but also for French Press. I
don't want to remove the oils if they impart a signficant flavor, but
if the oils are more likely to add bitterness, then I may try to get
rid of it. It should be pretty easy for me; I weigh out 16g of coffee
per double, so 'll just pour them onto a paper towel at dab a bit
befor grinding.



 
Date: 19 Apr 2007 19:44:30
From: diab0lus
Subject: Re: Is oil a good thing?
On Apr 18, 11:16 am, TedJ <theojo...@charter.net > wrote:
> I posted this on CG but got little response, so I'll try here.
>
> I usually roast into 2nd Crack, with the results that the beans take
> on a sattony sheen, but no surface oils. Within a couple of day the
> beans are spotted with oil, some varieties more than others.

Depending on what blend or SO I am roasting for espresso, I normally
roast until the first snap of second, a few snaps into second or,
rarely, start of rolling second. I haven't found desirable tastes
beyond that for espresso. A few nights ago I was roasting while the
sun was going down, the lighting changed (I roast outside) and I
roasted a batch too dark. I guess the smoke wasn't enough of an
indicator for me. The shot I pulled today tasted ashy with hardly any
origin characteristics. It was unpleasant. I had also roasted a
batch of the same blend to the first snap or five of second crack and
it was great. I haven't found any compelling reason to intentionally
roast so dark that oil covers the beans after resting, but maybe that
is your preference. Try roasting lighter, see if you like it. If you
do, try roasting even lighter. Great shots can be had without going
into second crack.

> I'm thinking of experimenting with removing these oils (beans on a
> paper towel) and seeing if I can detect any difference in the brewed
> coffee. Has anyone else done this?

I haven't, but the oily mess is annoying. You know, I assumed that
you were drinking espresso when I wrote above. What brew method(s) do
you use?

Ryan




 
Date: 18 Apr 2007 16:14:12
From: Flasherly
Subject: Re: Is oil a good thing?
On Apr 18, 11:16 am, TedJ <theojo...@charter.net > wrote:
> I posted this on CG but got little response, so I'll try here.
>
> I usually roast into 2nd Crack, with the results that the beans take
> on a sattony sheen, but no surface oils. Within a couple of day the
> beans are spotted with oil, some varieties more than others.
>
> I have two questions; first, what is the mechanism that transports the
> oils to the surface of the bean two or even three days after roasting?
> Is it the escaping gas which carries the oils or, as has been
> suggested, is it that the structure of the bean has broken down
> allowing the oils to simply migrate to the surface? Second question;
> what is the composition of the oil? Is it primarily sugar and caffeine
> or are there other essences of the coffee flavor? Are these surface
> oils something that we would rather not include when brewing our
> coffee, or are they something we should savor?
>
> I'm thinking of experimenting with removing these oils (beans on a
> paper towel) and seeing if I can detect any difference in the brewed
> coffee. Has anyone else done this?
>
> Thanks for you help.
>
> Ted J

Someone told me to roast until the first occurrence of oil present. I
inferred the oil wouldn't linger longer than under heat as a
transitory quality of the event. What you're experiencing after
roasting - oil rising to saturation followed by fermenting - I've also
experienced. Along with David - very nasty associated flavors if left
unchecked to propagate. Also the exception - it was a dark roast I
was after when I noticed the subsequent oils associated with storage
(by far unusual, again, since I seldom go into the second crack).

The prescription is best simply to work out of an air-tight container
of fresh roasted beans, cured intially, but then put away in the
freezer. Smaller portions don't last longer than a week to drink them
in quantities I roast.



 
Date: 18 Apr 2007 12:05:11
From: DavidMLewis
Subject: Re: Is oil a good thing?
On Apr 18, 8:16 am, TedJ <theojo...@charter.net > wrote:
> I have two questions; first, what is the mechanism that transports the
> oils to the surface of the bean two or even three days after roasting?
> Is it the escaping gas which carries the oils or, as has been
> suggested, is it that the structure of the bean has broken down
> allowing the oils to simply migrate to the surface? Second question;
> what is the composition of the oil? Is it primarily sugar and caffeine
> or are there other essences of the coffee flavor? Are these surface
> oils something that we would rather not include when brewing our
> coffee, or are they something we should savor?
>
If you're interested in this sort of thing, I'd recommend Illy &
Vianni, "Espresso Coffee, The Science of Quality". It has the single
highest concentration of recent research I'm aware of. The answer to
your first question is that roasting generates CO2 at enormous
pressure inside the bean, and the physical structure starts breaking
down during second crack. This allows the lipids, which contain many
different flavor compounds, to migrate to the surface. The problem is
that once there, they start to turn rancid. When they do, the taste
gets nasty quickly. At that point, though, you're pretty much done; I
don't think you could effectively remove the rancid oil, and much of
the flavor is gone by then anyway.

Best,
David