HomeRoast Digest


Topic: Sour coffee taste (10 msgs / 293 lines)
1) From: Scot Larson
Hi all,
I'd like to ask for some help/advice regarding a recent roast.  I picked up some green Mexican Chiapas from a local roaster and used it to christen my Quest (after a few batches of Tom's Thumbs Down.)  I took the beans to FC - 8 min to 1st, 11 to finish.  The flavor is OK, but there is a sour taste on the finish.  Not the standard acidic bite on the front of the tongue, but rather in the back.  Is this simply a question of bean quality or can this sourness be caused by something in the roasting technique.  I brewed with both French press and manual drip with the same results so I don't believe the brewing method is the culprit.  Any ideas?
Scot
p.s.  Great listserv.  This group has really helped me improve my roasting.
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2) From: Tom Ulmer
Without knowing any other details it seems to me the roast was a bit rushed.

3) From: Robert Bedwell
I agree with Tom.  I target temperatures at each interval beginning at at 4 minutes at 280F, 5 min @300, 6 min@ 320, 7, 8 and 9 min which is close to 1C.  From start of 1C to end of roast I shoot for 4 to 5 minutes.  WIth the target temperatures I can make adjustments earlier in the roast and pretty consistently achieve the total roast times that work best for me.
On Mar 26, 2011, at 9:21 AM, Tom Ulmer wrote:
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4) From: Barry Luterman
Seems a bit fast to me also. I am runining 9 min ti FC on a soft bean and
9.30 on a harder bean wit a finish of 13.30 to 14 30
On Sat, Mar 26, 2011 at 6:51 AM, Robert Bedwell  wrote:
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5) From: Michael Mccandless
Might consider running a little rice through the grinder,
Could be some tailings from previous roasts creeping in.
McSparky
On Sat, Mar 26, 2011 at 4:27 AM, Scot Larson wrote:
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6) From: Danny Gutierrez
Also, it could be under extraction with brewing. Try different brewing
methods and longer or finer grinds.
On Sat, Mar 26, 2011 at 8:25 AM, Michael Mccandless
wrote:
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-- 
Danny Gutierrez
~engage coffee~
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7) From: Danny Gutierrez
Ha, sorry, just read that you already canceled that one out...
On Sat, Mar 26, 2011 at 8:52 AM, Danny Gutierrez wrote:
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-- 
Danny Gutierrez
~engage coffee~
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8) From: Bryan Wray
I just want to chime in to say that you do not have to season a drum.  On=
e of the biggest old wives tales around.
Almost as bad as the seasoning shot after you clean a machine...
How long did you roast after first crack?
-bry
Bryan Wray
Compass Coffee
360.831.1480
Bryan
It is my hope that people realize that coffee is more than just a caffeine =
delivery service, it can be a culinary art- Chris Owens
--- On Sat, 3/26/11, Danny Gutierrez  wrote:
From: Danny Gutierrez 
Subject: Re: [Homeroast] Sour coffee taste
To: "A list to discuss home coffee roasting. There are rules for this list,=
 available athttp://www.sweetmarias.com/maillistinfo.html"
Date: Saturday, March 26, 2011, 8:52 AM
Also, it could be under extraction with brewing. Try different brewing
methods and longer or finer grinds.
On Sat, Mar 26, 2011 at 8:25 AM, Michael Mccandless
wrote:
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 but
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with
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mariascoffee.com
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mariascoffee.com
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-- =
Danny Gutierrez
~engage coffee~
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9) From: Tom & Maria - Sweet Maria's Coffee
How big was the batch? I don't think that is fast enough to give any 
off flavors. Many of my sample roasts are in the same range, but they 
are 100 gram batches too. Yours might be larger. Compare the whole 
bean surface color to a ground sample, side buy side. If the surface 
looks a lot darker than the interior then you might have 
under-developed interior. But I have another suspicion: the coffee is 
baggy. The reason is that Chiapas new crop would just barely be 
shipping right now, and that would be lower grown coffees. If its 
last years, was kept in jute, it's going to have little moisture 
content, roast weird, and probably have baggy taste too. Hard to say 
without seeing the green coffee. I could probably tell from a decent 
macro image of 20-30 green beans
tom
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-- 
-Tom
Sweet Maria's Coffee  -  Oakland, California  - http://www.sweetmarias.comHomeroast mailing list
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10) From: Tom & Maria - Sweet Maria's Coffee
Hi Scot - nice clear macro pictures! I am having some trouble because =
the color is really on the yellow side. I see that there are lighter =
areas on the edges of the coffee, especially the sharp edge on the =
flat beans. If those are whitish it might be age. The coffee looks =
nice, looks dense, nice preparation. But there is one thing: I see =
about 4-5 possible under-ripes. These are smallish, with silverskin =
(chaff) clinging completely to the rounder side and the flat side =
(silverskin itself is totally normal - good in fact). But these =
smaller ones covered in silverskin might be unripe green cherry - you =
really know when you roast to a lighter City roast, and find that =
these come out tan, a quaker bean. That would give sour and baked =
taste. Might be the issue, might not. DP coffees are the ones with =
quakers, but a washed Mexican can often have more than their fair =
share. The "back of your toungue" sourness sounds like astringency to =
me, which would be consistent with under-ripes.
PS - you can upload pics to the forum if you want to post the note =
along with the picture
Tom
Hi tom,
Thanks for reply.  I have been roasting 225g batches.  I checked the =
ground vs crushed vs whole color and they look very similar.  The =
beans were purchased in December of last year so it should be last =
year's crop.  Would a "baggy" flavor leave the sour taste on the back =
of the tongue?  I haven't tried any of the coffees from Sweet Maria's =
yet in the Quest.  I'll try a batch tonight.  Pics are attached. =
Please let me know what you think.
Scot
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-- =
-Tom
Sweet Maria's Coffee  -  Oakland, California  - http://www.sweetmarias.comHomeroast mailing list
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