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	FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
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Contents:
  2005 Novembeerfest homebrewing competition (Nic Templeton)
  Re: Wort Chiller Efficiency (Ricardo Cabeza)
  Kunze on batch vs continuous sparge efficiency ("steve.alexander")
  reply regarding analysis ("steve.alexander")
  re: racking of p-lambic (Steve Piatz)
  floating the grainbed ("Dave Burley")
  Batch vs. Fly Sparging Efficiency ("Dan")
  mash viscosity (Marc Sedam)
  RE: Wort Chiller Efficiency ("Mike Racette")
  RE: continuous sparge analysis ("Oswald John PA US")
  Re: reply regarding analysis (Steven Parfitt)


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Date: Wed, 5 Oct 2005 21:21:27 -0700
From: Nic Templeton <ntempleton at gmail.com>
Subject: 2005 Novembeerfest homebrewing competition

                                                                      
                                                                      
                                                                      
                                          The Impaling Alers are
pleased to announce the 2005 Novembeerfest homebrewing competition.

Novembeerfest will be held Saturday, November 5 at Larry's Brewing
Supply, 7405 S. 212th St. #103, Kent, WA 98032

Entries will be accepted from all BJCP/AHA beer style categories,
including cider and mead.  The style guidelines may be viewed at
http://www.bjcp.org/style-index.html.  Three bottles are required for
entry with an entry fee of U.S.$6.  The standard AHA entry form and
bottle labels may be used.  Entry forms may also be downloaded from
www.impalingalers.org.  Entries will be accepted through October 30
and may be shipped to:

Larry's Brewing Supply
7405 S. 212th St. #103
Kent WA 98032,
206-872-6846

Entries may also be dropped off at:

Mountain Homebrew and Wine Supply, 12121 N.E. Northup Way, Suite 210,
Bellevue, WA 98005, 206-882-9929
Bob's Homebrew Supply, 2821 NE 55th ST.  Seattle, WA  98105,  206-527-9283
The Beer Essentials  2624 112th St. #E-1  Lakewood, WA. 98499  253 581-4288
The Cellar Homebrew  14320 Greenwood Ave. N.  Seattle, WA 98133  206-365-7660
Olympic Brewing Supplies  2817 Wheaton Way  Bremerton, WA 98310  360-373-1094

If you have any questions, please contact Jim Hinken at
brews.brothers at verizon.net.


- --
Nic Templeton - Seattle WA



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Date: Thu, 6 Oct 2005 00:49:20 -0400
From: Ricardo Cabeza <expunged at gmail.com>
Subject: Re: Wort Chiller Efficiency

Craig -

Is your motivation to use less water mostly to save a little money? 
If so, this may be bad advice, but....

You could make a pre chiller upstream of your wort chiller that you
place in an ice bath. This would make the initial temperature of the
water incoming into your immersion chiller cooler, thus speeding up
the cooling rate and saving some water.

It's difficult to answer your question more directly without knowing a
lot of specifics about your chiller.  And even then, the answer
requires fluid mechanics and heat transfer theory.  I'm sure there are
several practicing Mech. Engineer forum suscribers that could better
answer this question than I could.

CT



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Date: Thu, 06 Oct 2005 02:36:05 -0400
From: "steve.alexander" <-s at adelphia.net>
Subject: Kunze on batch vs continuous sparge efficiency

As long as we are considering arguments from authority, here's one to 
top any preceding.  Kunze, "Technology Brewing and Malting", 
(translation of the 7th addition), states the following on batch vs 
continuous sparging.

pp235-236: "The first wort is allowed to run off only until the spent 
grain becomes visible.  Then the sparge water is layered on top of the 
wort and gradually displaces the wort downwards.  The spent grists are 
thereby extracted but this process needs a little time because the 
extract is not dissolved from the spent grains very rapidly.  It is 
possible to sparge continuously, i.e add as much fresh water as second 
wort flows out below, or sparging can be done in several separate 
sparges [sja- batches].  Of course sparging is rather quicker if it is 
done continuously, but the yield is higher if two or three small small 
sparges are used because the sparge water then has more time to extract 
the spent grain contents.  The limited mixing [sja- between batch 
sparges], and therefore greater extract difference between the sparge 
water and the extract solution contained in the spent grains, 
accelerates the washing out of the extract (extraction).

Kunze continues, "Both procedures are used commonly in practice.  The 
decision whether to use continuous or periodic [sja- batch] sparges 
depends principally in the brewhouse utilisation.  When time does not 
play an important role, because of the higher yield, sparging is 
performed in several steps [sja- batches]".

Kunze repeats the same result more briefly on page 286, "More, small 
sparges give a higher yield than continuous sparging".

I don't know what inspired the popular error that batch was less 
efficient.  It make no sense when you examine the problem.

 -S




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Date: Thu, 06 Oct 2005 06:43:22 -0400
From: "steve.alexander" <steve-alexander at adelphia.net>
Subject: reply regarding analysis

David Harsh <dharsh at fuse.net>
Writes,

> [...] he hasn't modelled the grain bed
> used in any lauter tun I've ever encountered.
>
> Look at the process as described in the model:
>
>> "S/2 case":
>> Step 1: remove S/2 of the original mash water. <snip>
>> Step 2: After equilibrium, we again replace S/2 of the liquid.
>> <snip>
>> Drain: Finally we drain the (M+X-U) volume of liquid
>
>
> What is described here is a sparge process where the grain bed is
> continuously stirred 

No Dave there is no stirring.  The (dis)continuous sparge 'replacement' 
step involves removing a fixed amount of (extract laden) solution and 
replacing it with sparge water and waiting for equilibrium before 
removing the next 'unit' of solution and replacing it.  Of course  you 
must understand that this is a mere mathematical prop, since the 
"continuous" sparge appears when we make the replacement volume 
infinitesimally small.

Of course this simple model doesn't account for the concentration 
differences between the top & bottom of the grist bed, but with shallow 
beds I doubt this factor changes the outcome.   In fairness we should 
also point out that fly sparging extracts more from the top of the grist 
heap and less from the bottom, and suffers in comparison to the uniform 
extraction of batch.

> If properly modelled, I doubt that the batch process would be found to
> more efficient.

When we devolve to the point of voting on facts I'll keep your 
unsupported opinion in mind.  You'll be pleased to read that 
professional brewing texts disagree with your opinion.  My crude model 
disagrees with your opinion.  In fact no credible evidence has yet been 
presented supporting your opinion.    Support it with something 
thoughtful or talk to the hand.

> So why would mash out help efficiency? [...] The
> only thing left is the equilibrium sorption relationship - the isotherm
> I mentioned earlier. I would suspect if there's an effect, that's
> where we'd find it.


Now that I appreciate, a serious lead.  Thanks.

===
Steven Parfitt writes,

> Ah-Ha! But are they really near equilibrium? How long
> does it take to reach this equilibrium?

This is a completely valid criticism of this simplified model, so let's 
address it.  That last question is easy - it takes infinite time to 
reach equilibrium, but it's "close enough" in minutes.

According to a graph from Royston, [JIB v72,pp351], reproduced in M&BS 
vol1, pp 350, the percent of lab extract obtained vs run-off time 
associated with late runnings (which is not exactly the data I would 
hope to have) is 97% at about 30 minutes and 94% at 15 minutes and his 
arbitrary gold-standard 100% effectively at 2 hours.     This doesn't 
exactly give us a time constant to work with, but it at least gives is a 
sense of where we stand.  Most batch steps are roughly 30 minutes I suspect.

> If not, then the equations need to be driven by the
> differnece between in extract solution and not in
> solution in which case fly sparge creates a greater
> differnetial to drive the equations. 

Yes, differential extract concentration and time are the important 
factors in the diffusion of extract into the free liquid, but I don't 
see any argument that concludes that fly sparge have less extract in 
solution on average.  The opposite is clearly true at T=epsilon, 
immediately after the free mash water is removed and replaced by the 
first sparge water(for batch).   It is a very long time after that 
before a comparable fly-sparge drops to a similarly low free-liquid SG.
- --
Another way of looking at this - is how low does the fraction of the 
ideal equilibrium extract (considering the part lost to lack of 
equilibrium)  do we need to get to  before a batch sparge is as bad is 
the ideal/perfect_equilibrium fly sparge.

If we assume the 1-sparge case works according to Tuesday's example we'd 
have E = 93.7% efficiency in the ideal case.   To drop down to E=89.2% 
like the continuous best-case, we'd have to collect only 79% of the 
ideal-equilibrium free-liquid extract at each sparge.    According to 
the reference above we'd expect to get around 94% in 15 minutes.    A 
1-sparge w/ 15 minute rest seems certain to be a better than a continuous.

For the 2-sparge case, we'd have to collect a mere 59.8% of the ideal 
equilibrium extract  before the 2-sparge would be a bad as the ideal fly 
sparge.

> Therefore, IF one waits long enough to reach
> equilibrium batch sparge will be more efficent. But
> fly sparging may be more efficient if sparging is done
> before equilibrium is achieved.


Yes, exactly, but the "long enough" is apparently less than 15 minutes 
per batch sparge rest.

==

Sorry, but I can't resist.

Dave Burley writes ....

> Here is a simple way to think about it.
>
> [...]  batch sparge, in
> which the final sparge has a specific gravity of say 1.030 or 
> whatever, and
> the continuous sparge has a value of 1.006 or less, there will be a clear
> difference in the amount of sugar left in the grain.[...]

I laughed and I laughed ...

Holy Hamburgers Dave, don't you recognize the logical fallacy of Petitio 
Principii - also known as begging the question.   In the paragraph 
above, Dave attempts to *prove* that that continuous is more efficient 
than batch, by *assuming* as a premise that batch final runnings are 
"1.030 or whatever"  and continuous are "1.006 or less".  ((This isn't 
the case of course )).   I counted 5 major logical fallacies in this 
post by Dave.  C'Mon Dave, I remember when you make a coherent argument 
that red was blue.    You're not trying.

===
Bill Velek writes,

> so the mass of extract
> is then X * 1.55."
>
> Was that extraneous info, [...] ?

Yes - it's extraneous to the current model.   I though I might eventually
need to calculate differential SG to address  diffusion.  Then extract
mass would be useful.

 -S



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Date: Thu, 6 Oct 2005 08:05:58 -0500
From: Steve Piatz <piatz at cray.com>
Subject: re: racking of p-lambic

Keith Busby asks:

> Am I right in assuming that it is undesirable to rack p-lambics (or sour
> beers using Wyeast Roeselaere) to secondary at all?

The micro-organisms in a lambic and a Flanders Red are very similar,
the big differences are the grist composition and the processing during
fermentation and aging.

For a p-lambic you don't want to rack the beer.  For things like a
Flanders Red you need to rack off the trub before starting the aging
process.  Take a look at Jeff Sparrow's "Wild Brews" for more details.

- -- 
Steve Piatz


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Date: Thu, 6 Oct 2005 10:21:03 -0400
From: "Dave Burley" <Dave_Burley at charter.net>
Subject: floating the grainbed

Brewsters:

Bill Velek asks about floating the grain bed and is told in another forum
you have to add air to the grain bed or not stir it so air stays there.  

Errrrrttt not true.  You will do bad things to your beer from oxidation of
the hot wort. Where do these ideas come from?

The term floating refers to the grain bed behavior when the SG of the wort
exceeds the bulk density of the grain particle. Sorta like Ivory soap or you
in the Great Salt Lake.

This happens when you are making high OG beers or are making a double batch
which you will dilute. Many brewers never see this if they are making
BudMilloors type beers and using a dilute mash.

Of course once you begin the sparge the OG drops below the bulk density and
the grain column settles.

You will never (maybe I shouldn't say never) have a stuck mash if your grist
grind is correct and you start the wort withdrawal slowly after waiting a
few minutes after placing the mash in the sparge vessel.

Keep on Brewin'

Dave Burley



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Date: Thu, 6 Oct 2005 10:27:30 -0700
From: "Dan" <Dan at teeleengineering.com>
Subject: Batch vs. Fly Sparging Efficiency

Okay, let's put this debate to bed before it degenerates into argument.
There has been some great information tossed around the last few weeks, but
it was all fundamentally flawed. Every post I read either used assumptions
as fundamental data and/or depended upon a static homogeneous condition in
the grain bed. So, while people may be on the right track thought-wise (I'm
not naming names 'cause I ain't sure myself), none of the arguments can be
viewed as 'convincing' or ir-refutable. And everybody here remembers the
difference between 'theory' and 'reality', RIGHT?

So, where does that leave us? I propose an experimental challenge. The
leaders of both camps are accomplished brewers. I propose that each brewer
perform a side-by-side comparitive mash. Pick a recipe and conduct a
side-by-side mash/sparge; one being a fly sparge and the other a batch
sparge. THEN, conduct a final 'batch' sparge on both grain beds and compare
the SG's of the final sparges. VOILA! A practical, real-world conditions
comparative data point. What say ye?

Of course there are assumptions still involved in even this experiment,
which will keep the debate alive. The assumptions that I'm aware of are that
the ingredients will be identical in terms of grain crush, extract
potential, etc. and that the brewers' mashing/sparging techniques will be
comparable to each others (given their combined brewing experience). Both of
these can be easily overcome with some planning and ground rules, but I
leave it to the 'experimenters' to determine how determined they really are
to resolve this friendly debate.

ON YOUR MARKS! GET SET!............BREW!!



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Date: Thu, 6 Oct 2005 11:05:19 -0400
From: Marc Sedam <alechemist at bellsouth.net>
Subject: mash viscosity

Although the thread seems to be trickling to a close, I'll add one last bit...

Yes, the mash viscosity is affected by enzymes.  This will be ridiculously 
moreso when you're talking about a mash viscosity made of very fine 
particles continuously stirred as the mash temps are raised.  Two 
concurrent things are happening:

1)  The amylases are active.  Alpha amylase was shown to act on intact 
starch granules back in the early 90's.  And no, I don't have the reference...
it was done in an adjacent lab to mine at National Starch and Chemical 
Company.  The scientist's name was Xu-Feng Wu.

2)  More importantly, though, is the gelatinization PROCESS (not 
gelatinization itself).  Think of starch granules as little pieces of popcorn.
  Two things cause the granule to open up and make the starch chains 
available for digestion--temperature and shear (stirring).  As the 
temperature increases the granules begin to allow water in and outer 
boundary of the starch granule starts to dissolve away, allowing access 
to the long chain starches. This process is dramatically faster when 
stirred, which is why I often stir the top 2/3 of my grain bed a couple of 
times during the sparge (no splashing, always a water boundary on top, 
blah x3).  As the starch granules swell the viscosity will rise very quickly.  
This is what Jeff sees in his cereal mashes.  Once the temperature rises 
above the gelatinization temps (if I remember correctly it's in the 57-60C 
range for malted barley and 63-65C range for corn) the swollen granules 
break apart and gelatinization is completed, allowing the enzymes to act 
on the entire contents.

So this viscosity increase/decrease is both an enzymatic and a physical 
process.  You can get complete starch gelatinization without enzymes 
(like when you make gravy with corn starch) but the process is made 
easier by the enzymes as the "peak" viscosity isn't so high.

To me, the viscosity of the mash is mostly irrelevant as you could change 
it by simply adding more water to increase the liquor/grist ratio.  The 
viscosity of the WORT is marginally more important.  Actually, strike that, 
for me it's not important either.  Interesting, yes, but not important.

3)  Mash-outs are recommended for a couple of reasons.  First, it kills 
off the enzymatic action of the wort (mostly).  Why do we care?  If you 
want to "fix" the attenuation of the beer reproduceably, then you want the 
enzymes dead at the same time frame time after time.  Alpha amylase 
can still be a pretty active little molecule at high temps, and can affect 
the attenuation during the short time it remains active during the wort's 
way to boiling.  The second reason is that there are always some 
ungelatinized starch molecules that make their way into the wort (esp. 
if you mash at low temps).  A mash out allows for a quick temperature 
increase to gelatinize any remaining starch...AND allows the enzymes 
a quick whack at whatever starch is left over.   Since most beers don't 
want starches in the wort, both for haze and shelf-stability issues, this 
helps finish off the job.


All of this is very relevant for larger brewhouses where a couple of 
minutes (or tens of minutes) in the runoff can increase throughput.  
In the smaller homebrew setting the effects are more negligible, but 
illuminating in terms of understanding what's going on with your 
process prior to fermentation.



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Date: Thu, 6 Oct 2005 09:15:02 -0600
From: "Mike Racette" <mike.racette at hydro-gardens.com>
Subject: RE: Wort Chiller Efficiency


Pete Limosani asks about Wort Chiller Efficiency:

I have wondered the same thing when chilling - whether its more efficient to
run the water faster or slower - and I'll let others try to answer this,
but, I would suggest this:

Find a way to recycle the water you're using. I have rigged up some black
poly pipe to run from the end of my chiller directly to my large-capacity
washing machine which will hold most of it. Anything else, I run into five
gallon buckets and use for watering plants, etc. A little tedious, I admit,
but it eases my conscience greatly - after all, brewing does use a ton of
water.





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Date: Thu, 6 Oct 2005 10:17:11 -0500
From: "Oswald John PA US" <john.oswald at cibasc.com>
Subject: RE: continuous sparge analysis

I need clarification?
I'm new to home brewing (~2yr) but not to extraction and filtrations
(18yr experience in chemical industry).
So when Steve Alexander describes the continuous sparge as "Now instead
of draining this entire amount as in batch sparging...."
What??? Steve's math starts correct but is complicated as written (an
Excell spreadsheet is far less confusing). But his described
"continuous" sparging technique is truly a worst case senario in
liquid-solid extractions and I doubt actually practiced in the HB world
either.
A correct comparison of the two methods must begin with the same amount
of unextracted wort "U", "...where we drain the mash water...".
Why in the world wouldn't you want to first drain the wort until you get
to the surface of the spent grains? The only other descriptions of
continuous sparging I have read do just that and then begin the
continuous wash of the grain bed to EXTRACT the remaining wort? 
Adding the sparge before the initial run is silly. It's like rinsing in
the clothes washer before pumping out the wash water. Of course it will
take forever and be less efficient.

If I am way off from what is normal in the HB world, please let me know
and I'll write a book about how to drastically improve homebrewing!

I love this discussion!
John



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Date: Thu, 6 Oct 2005 08:56:09 -0700 (PDT)
From: Steven Parfitt <thegimp98 at yahoo.com>
Subject: Re: reply regarding analysis

Steve, thanks for your reply.

I don't have access to your sources and was unable to
locate any references on the internet (great source of
info, but not perfect by any means).

Was the reference (According to a graph from Royston,
[JIB v72,pp351], reproduced in M&BS  vol1, pp 350,") a
labratory test using fine grind (almost flour like
consistnecy) or was it based on a grind we would
normally encounter in home brewing? If it was a find
grind then the time would much shorter than would be
required in our case.

Generally I do my mashes and sparges very slowly. I
finished a batch of Belgian Ale Tuesday which I
started the mash before I went to work (7am) and did a
mini decoction to boost the temp to mash out at 6pm,
then let it rest ten minutes and sparged until after
7:30pm. This batch was mashed in a 5 gallon Gott
cooler with a bazooka screen as a filter.

The batch was 10# of grain inculding 1# of wheat that
I had not ground well (some grains intact, I had
palyed with my Vally Mill and probably mis-adjusted it
last week). 

I collected 5.5 gallons of 1.059 wort (stopped when I
got a reading of 4Brix, then sparged the remains to
collect what boiled down to one gallons of 1.024 wort
to use for starters. The last running from the tun
barely showed (0.2 Brix) on the ATC refractometer.

Theoretically I collected 59*5.5 + 24 = 348.5 pts from
the 10# of grain or 34.85 pts/lb (97% efficency?). 

If the last runnings were 0.2Brix it would indicate
that there should be somewhere around 2pts of extract
remaining in the grain.(assuming the 1 gallon of
remainng liquid).

In the case of your example with one sparge following
the initial draining of the tun you gave the remaining
extract at 27.77% of initial potential extract, or
0.2777 * 36 * 10 = 99.97pts. This would be in solution
in 3.4 + 1 gallons of water which should give  1.2272
sg.

Isn't this higher than the remaining extract in my
case when I switched my collection to the starter pot?

How can a finishing gravity of 1.02272 be less than
the 1.016 finishing gravity I experienced? (Comparison
of theory to practice?)

I think this is the point that has a lot of people
confused. It does me.

I normally sparge until I hit 1.016 (4 brix) compared
to batch a sparge with a higher gravity in the last
batch than the terminal gravity when sparging. How can
the higher finish gravity be more efficient?

Steven Parfitt
 
- --- "steve.alexander" <steve-alexander at adelphia.net>
wrote:

 .....snip.....

> ===
> Steven Parfitt writes,
> 
> > Ah-Ha! But are they really near equilibrium? How
> long
> > does it take to reach this equilibrium?
> 
> This is a completely valid criticism of this
> simplified model, so let's 
> address it.  That last question is easy - it takes
> infinite time to 
> reach equilibrium, but it's "close enough" in
> minutes.
> 
> According to a graph from Royston, [JIB v72,pp351],
> reproduced in M&BS 
> vol1, pp 350, the percent of lab extract obtained vs
> run-off time 
> associated with late runnings (which is not exactly
> the data I would 
> hope to have) is 97% at about 30 minutes and 94% at
> 15 minutes and his 
> arbitrary gold-standard 100% effectively at 2 hours.
>     This doesn't 
> exactly give us a time constant to work with, but it
> at least gives is a 
> sense of where we stand.  Most batch steps are
> roughly 30 minutes I suspect.
> 
> > If not, then the equations need to be driven by
> the
> > differnece between in extract solution and not in
> > solution in which case fly sparge creates a
> greater
> > differnetial to drive the equations. 
> 
> Yes, differential extract concentration and time are
> the important 
> factors in the diffusion of extract into the free
> liquid, but I don't 
> see any argument that concludes that fly sparge have
> less extract in 
> solution on average.  The opposite is clearly true
> at T=epsilon, 
> immediately after the free mash water is removed and
> replaced by the 
> first sparge water(for batch).   It is a very long
> time after that 
> before a comparable fly-sparge drops to a similarly
> low free-liquid SG.
> --
> Another way of looking at this - is how low does the
> fraction of the 
> ideal equilibrium extract (considering the part lost
> to lack of 
> equilibrium)  do we need to get to  before a batch
> sparge is as bad is 
> the ideal/perfect_equilibrium fly sparge.
> 
> If we assume the 1-sparge case works according to
> Tuesday's example we'd 
> have E = 93.7% efficiency in the ideal case.   To
> drop down to E=89.2% 
> like the continuous best-case, we'd have to collect
> only 79% of the 
> ideal-equilibrium free-liquid extract at each
> sparge.    According to 
> the reference above we'd expect to get around 94% in
> 15 minutes.    A 
> 1-sparge w/ 15 minute rest seems certain to be a
> better than a continuous.
> 
> For the 2-sparge case, we'd have to collect a mere
> 59.8% of the ideal 
> equilibrium extract  before the 2-sparge would be a
> bad as the ideal fly 
> sparge.
> 
> > Therefore, IF one waits long enough to reach
> > equilibrium batch sparge will be more efficent.
> But
> > fly sparging may be more efficient if sparging is
> done
> > before equilibrium is achieved.
> 
> 
> Yes, exactly, but the "long enough" is apparently
> less than 15 minutes 
> per batch sparge rest.
> 
> ==

 .....snip.....



		


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---