HomeRoast Digest


Topic: Sour beans (7 msgs / 175 lines)
1) From: Nils Kenaston
I want to appear as refined as the next person, but every time I try  
to roast for espresso, lighter than Vienna, I risk a sour nasty  
shot.  Alright, I am lying - it is not so much when I roast as when I  
buy  (but since this is a roasting discussion)  Personally, I  
inevitably roast to 465 degrees in a modified popper, about 30  
seconds into the thick smoke stage - probably Vienna.  After a few  
days the beans taste pretty good but there is certainly no sense of  
varietal distinction.  I have been to northern Italy.  I have tasted  
their sweet light espressos.  It would be nice to re-create that  
flavor.  Once in awhile I'll shell out $12-$15 lb for some boutique  
roasted espresso and the results can be aweful.  Currently I am  
sitting on a lb of Dallis Roasted NY Five Bean Espresso, Full City  
Plus.  I am pulling undrinkable shots from my PIDed Silvia.  I think  
the temp is dialed in.  I just ran some cleancaf through her to rule  
out a dirty machine.  The flavor is that of a too cold shot or rancid  
oil.  Maybe the beans are just stale.  The next time I roast I will  
try to go lighter - that way I can rule out stale beans.  I am not  
sure what my question is.  I think I am just looking for  
encouragement and perhaps some war stories in the quest for a refined  
full city plus which does justice to the distinction of the beans.   
(I have been roasting Malagar Gold - any suggestions in refining my  
elaborate roast profile?)
Thanks
Nils

2) From: miKe mcKoffee
Sour shot usually indicative of too low shot temp. Generally speaking the
lighter the roast the higher the shot temp.
Kona Kurmudgeon 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.
Sweet Maria's List - Searchable Archiveshttp://themeyers.org/HomeRoast/
 
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3) From: Nils Kenaston
I am a little jittery.  I just pulled about a dozen shots at  
different temp settings.  It seems I can get a drinkable shot 5-7  
degrees cooler than my normal temp setting - I dropped from 217  
degrees (at the boiler) to 210 degrees.  Have others found that a  
lighter roast benefits from a lower temperature espresso shot -  
intuitively I would think it is the other way around.  Perhaps all my  
shots have been too hot and with a darker roast this is masked.   
Perhaps I have had way too much coffee.
Nils

4) From: Mike Koenig
Nils,
It sounds like you might still be a little low (though this depends
heavily on where your thermocouple is placed on your boiler, and the
calibration of your PID).  I've been running at 105 C (221 F), which
gives me ~92 C (~198 F) shot temp, as measured with a thermocouple
stuck into the side of a styrofoam cup and held unter the grouphead.
From what I've read, I seem to be on the low side, I see a lot of
people refer to 228 F as the typical setting.
Ultimately, it is the taste that matters,  but a good way to find out
if you are "in the ballpark" is to try to measure the actual
temperature of the water output. (do a google search for a better
description than I gave above).
PID temp calibrations can also be way off...mine was about 3 C off
when I calibrated it with boiling water.
--mike
On 4/3/07, Nils Kenaston  wrote:
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5) From: miKe mcKoffee
If your shots are tasting good to you that's what counts.
However, I'd caution anyone with a PID'd Silvia not to rely on those
numbers. Many years worth of many PID Silvia users indicates usual boiler
temp reading ~28f higher than shot temp, ie a 228f boiler temp yield ~200f
shot. (with usual external boiler surface tc placement at tstat screw.) This
is for first shot in a series. Shot temp will rise in a series a couple of
degrees f per shot peaking about 12f higher when group temp
saturated/equalized. How fast the group temp rises in a series also varies
depending on your shot temp build speed.
Kona Kurmudgeon 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.
Sweet Maria's List - Searchable Archiveshttp://themeyers.org/HomeRoast/
<Snip>

6) From: Mike Koenig
Nils,
It sounds like you might still be a little low (though this depends
heavily on where your thermocouple is placed on your boiler, and the
calibration of your PID).  I've been running at 105 C (221 F), which
gives me ~92 C (~198 F) shot temp, as measured with a thermocouple
stuck into the side of a styrofoam cup and held unter the grouphead.
From what I've read, I seem to be on the low side, I see a lot of
people refer to 228 F as the typical setting.
Ultimately, it is the taste that matters,  but a good way to find out
if you are "in the ballpark" is to try to measure the actual
temperature of the water output. (do a google search for a better
description than I gave above).
PID temp calibrations can also be way off...mine was about 3 C off
when I calibrated it with boiling water.
--mike
On 4/3/07, Nils Kenaston  wrote:
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7) From: MichaelB
Nils,
I have gradually converted over decades of espresso consumption to lighter
roasts. Home roasting gave me an appreciation of varietal taste that I was
not even aware of a few years ago. One of my criterial for an espresso blend
is that all the beans be palatable. So no robusta in my blends. (Maybe
that's the taste you find objectionable in your store bought blends.) I
recommend that you try Sweet Maria's Monkey Espresso Blend which tastes
wonderful at all roast levels. I usually roast it between 10 and 30 secs
into 2nd. But sometimes to just the hint of 2nd, and sometimes a full minute
into 2nd (subjectively a very long minute!). IMO this blend has wonderful
varietal flavors AND wonderful roast flavors, so it is fun week after week
to climb the range and enjoy the variations.
If you are buying roasted, Tom has a different espresso offering every week.
He roasts on Monday and ships that night or next day. Wait for a choice that
interests you. Here's what is coming next Mondayhttp://sweetmarias.com/prod.roasted.html.Buying his roasts is a good way to
compare your results to an expert - something we mostly solitary home
roasters don't get to do often enough.
On 4/3/07, Nils Kenaston  wrote:
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--
MichaelB


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