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Topic: HX shot temps> RE: +Expobar Brewtus and La Spaziale S1 (14 msgs / 418 lines)
1) From: miKe mcKoffee
	From: homeroast-admin
[mailto:homeroast-admin] On Behalf Of Clifton
	Sent: Sunday, September 10, 2006 9:20 AM
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	I have a couple of beans that I can get great results with my
Giotto. However some of the beans have an optimum brew temp that is slightly
lower and trying to hit that temp constantly with an HX machine is touch and
go for me. 
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What type of HX shot temp management are you using after cooling flush (or
during a series of shots), flush & rebound or flush & go? For cooler shot
temp flush & rebound either flush more and rebound same length of time or
flush same and pull shot sooner. I use the "pro" flush & go. Basically flush
to end of flash will be ~206f, each one-one thousand count after end of
flash lowers shot temp ~1f. Not a problem accurately within + or - 1f
hitting any shot temp desired ~196f to ~206f. (As accurate as a 1C
resolution DB:-)
Obviously electronically temp controlled DB you'd simply change the shot
boiler temp setting and wait for change to take effect. Speeding lowering
temp change by flushing to cool.
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.

2) From: Barry Luterman
As I have previously stated that's one of the nicest things about the 
Brewtus. With the double boiler plus HX set up changing temperature between 
shots is very fast. Only a matter of a few seconds to change one degree 
Celsius

3) From: Clifton
Mostly flush and go. I use an Illy cappa cup and run it for about 15
seconds. I go about 10 seconds if it is a repeat shot. It takes me a bit
over 30 seconds to go from removing the portafilter to brewing so I =
usually
grind while pulling the blank. This is with the bar at 1.0. If it has =
just
cycled it is at 1.1 to 1.2 so I may pull a bit more water to get it back =
to
1.0 or if I am trying to get a bit warmer I will go with the bar still =
at
1.1. I try not to go over a minute between grinding the coffee and =
brewing,
but sometimes I run a tad long. My variability is such that I have just
started keeping a log on shot temps for a given bean and don't really =
have
much accurate data to go by.
Clif - SomeWhere in Florida 
with Rocky the Cardi and Garfield the Tabby
Odie PWC at the Bridge 01/18/2006http://www.freewebs.com/aesk/inmemoriam.htm

4) From: miKe mcKoffee
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If I understand you correctly your normal shot procedure is the flush, build
the PF, then pull the shot without additional flush. This is considered
flush and rebound. Specifically you're flushing to below shot temp and
waiting for machine to rebound back to shot desired temp. This method if
waiting too long you'll get above 206f! How quickly a machine rebounds
depends on boiler size, heater power and boiler pressure. Flush & go is just
that, flush and immediately pull the shot. (in less than 5 seconds) I flush
& go more accurate to hit a desired shot temp rather than counting rebound
time which is also too much like surfing Silvia! Flush & go from machine
idle you first pull a cooling flush, build PF, gently set PF down, then
flush listening (and/or watching) for end of flash. End of flash will be
~206f. Each one-one thousand count beyond end of flash lowers temp ~1f. I
flush for flash flush & go with empty group, some build basket out of PF
then insert after flushing through PF without basket or use second PF. For
instance targeting 200f shot temp I'd count one-one thousand to six-one
thousand (six count) then immediately pull the shot.
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.

5) From: Clifton
Thanks I'll try that second flush!
Clif - SomeWhere in Florida 
with Rocky the Cardi and Garfield the Tabby
Odie PWC at the Bridge 01/18/2006http://www.freewebs.com/aesk/inmemoriam.htm

6) From: Zara Haimo
MiKe wrote:
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idle you first pull a cooling flush, build PF, gently set PF down, then
flush listening (and/or watching) for end of flash. End of flash will be
~206f. Each one-one thousand count beyond end of flash lowers temp ~1f.
I've got an HX machine too (ECM Giotto), but I haven't gotten as
sophisticated in temp surfing as you have.  Could you please explain what
you mean by "end of flash"?  Is that something particular to the Bric or
does my Giotto do it too?

7) From: Leo Zick
on the giotto (and im sure w/ all HXs), at the beginning of the flush  
the water spurts out at near boiling temps.  (use a single spout PF,  
or a naked/none at all to really tell).  at the equilibrium where the  
water heats/head cools it will stop sputtering and stream out.  its at  
that point that i start counting down from 206, 205, 204, etc.  i  
typically count down to 199 or 198, then put prepared basket into PF  
and pull my shot.  im guessing the 'rebound' temp is a degree or 2  
higher from this few second delay.  just methodically try this  
approach for each coffee type you use, and see what works best. :)
from what ive seen, SM classic italian is best around 201-202 to me.
Quoting Zara Haimo :
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8) From: miKe mcKoffee
That's pretty much it except the water coming through the HX causing flash
at group is actually 'above' not near boiling. It's the above boiling water
hitting the group that causes the flashing steaming water. As far as I know
all HX machines will be over temp from idle, nature of the design with HX
system running through much hotter boiler. As noted flash can be visually
observed as the water "dancing" from PF spout, usually with a very brief
stop in flow as flash ends, or as I do via listening with a cup held up to
group tilted towards me to reflect the flash sound.
Important to note that from idle state versus back to back shots end of
flash will not be ~206f but higher and hence the initial cooling flush from
idle. How much higher is variable depending on machine AND machine boiler
setting. (Cooling flush for first shot toughest thing to determine without
Thermofilter.) For instance on my Bricoletta running 1.0bar bottom of 0.5bar
deadband pstat (Barksdale) which yields total 0.1bar swing with over shoot,
end of flash from idle state yielded 209f not ~206f a couple minutes ago via
Thermofilter. OTH from idle state simply pulling Thermofilter shot no flush
at all yielded 215.9f! I've determined I need ~12sec beyond flash cooling
flush, which is ~8oz, to get the Bric' approximately in production state.
Based on reports from others the Bric' seems to need a larger cooling flush
than many or most other HX machines. When I was running 1.1-1.2bar swing
needed longer cooling flush of course. HX trade off between lower steaming
power and shorter flush also recovery speed effected. 
What is really important isn't what the shot temp actually is but what's in
the cup and being able to reproduce the group temp state for desired cup.
The basic rules of if sour pull higher temp if bitter pull lower temp are
what really matter! HX temp surf methods are what makes this possible
relatively repeatably. (assuming proper grind/dose/distribution/tamp of
course so there's no channeling causing over extracted bitterness)
Flush & rebound (flushing below shot temp and waiting for temp to 'rebound'
back up) versus flush & go is the other method often used. While I've found
flush & rebound to be more intra-shot stable it's more of a PIA to have to
up count 30 or 35 or 40 or whatever seconds from flush to hit a desired
inter-shot temp while building PF. And way too much like surfing Silvia!
Other's prefer flush & rebound.
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.
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9) From: Dan Bollinger
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Mike,  My interpretation is that it is water above the boiling point restrained 
by the approx. 1.3 bar pressure vessel being released into the environment where 
the atomospheric pressure is about 1 bar.  It is this change of pressure, not 
contact with a piece of metal, that allows the water to boil.  No different 
than, say, removing the radiator cap on a hot vehicle.   Dan

10) From: Leo Zick
yes, i agree, the water flashes. thats why i said 'near' boiling, not  
above, b/c it can vary once in the atmosphere, and cools really fast,  
from prolly 250degF to ~200ish.
Quoting Dan Bollinger :
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11) From: miKe mcKoffee
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As I understand HX design the water coming through the HX system is not
integrated with the pressure of the boiler at all but rather is like it's
own small boiler heated by the main boiler temperature. Agree the 'flash'
actually caused by the above boil steaming water itself hitting the
atmosphere not metal, especially since I flash flush & go with no PF in
group going simply by sound! But it wouldn't be caused by the difference in
boiler pressure versus atmospheric pressure since HX system goes through but
is not part of the pressurized boiler system itself.
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.

12) From: Greg Scace
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-Greg
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13) From: Leo Zick
1 bar is boiler pressure, isnt it?  is boiler pressure related to brew  
pressure?  well, dump question, i guess boiler pressure is indirectly  
related, right; higher pressure means higher boiler temps, means  
higher brew line temps. right?
i guess the tighter deadband allows for somewhat more accurate temp  
profile during a shot, correct? otherwise, i dont see a benefit other  
than it cycling the boiler that much more..
my giotto is the same ; initial flush is longer, 6-8oz, then letting  
the sucker sit on all day will get it really stable.  maybe ill start  
turning it on at night before bed so its really stable in the morning,  
rather than waiting till afternoon to have a better idea of what to  
expect :)
Quoting miKe mcKoffee :
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14) From: miKe mcKoffee
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Yes, boiler pressure determines boiler temperature which heat HX line,
though doesn't effect brew pressure much. (Easily verified measuring brew
brewing with totally cold machine.) 
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0.05bar deadband pstat ~equivalent to 1C electronic deadband control like on
S1 & Brewtus, though of course with them it's the brew boiler itself being
controlled.
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Think timer. I was leaving the Bric' on 24/7 but switched to coming on 5am
then off 10pm. Mainly for "just in case scenario" if pstat fails in always
on position, most common pstat failure. Most high end prosumer machines need
a good hour to be fully warmed up. There have been a few times I've used a
"speed" warm-up with the Bric' when waking up early. Basically after
initially coming up to boiler pressure/temp pulling a 4oz blank with a
minute wait then repeat 6 times. (Determined via Scace needed seven 4oz
heating blanks with the Bric') Does a fairly good job of heating the group
and brew path, though entire machine body etc. not up to temp. Works ok for
a wake-up Americano. 
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.


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