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Contents:
  Making highly fermentable wort(1/2) ("-S")
  Making highly fermentable wort(2/2) ("-S")
  re: Round two - Enzymes Next question ("-S")
  Re: Enzymes (extraction, half-lifes and location) ("Fredrik")
  Two Scholarships for Siebel Institute ("Keith Lemcke")
  UK Yeast Event (Signalbox Brewery)
  Spirit of Free Beer XIII ("Mark E.  Hogenmiller")


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Date: Tue, 5 Apr 2005 00:46:53 -0400
From: "-S" <-s at adelphia.net>
Subject: Making highly fermentable wort(1/2)

Lou Heavner asked followup offline.  Having known Lou thru HBD for quite a
few years I feel he won't object to my posting the exchange.

> BTW, if it isn't a trade secret or anything, how would you mash for
maximum
> fermentability and dryness.  [...]  I don't have a way to heat the mash
except
> with infusions or decoctions. [..]   I guess I'm wondering if you can say
with
> reasonable confidence and typical base malts (I usually use pale malt as
> the base, but sometimes Pils and rarely Munich) what would be the ideal
> temps, grist/water ratio, process (infusion vs decoction), etc.  How would
> you vary things for different malts as described above or the case of
weizens
> where ~ 50% of the grist is wheat malt, which I understand is also loaded
> with enzymes.

The wort contains some materials (protein, phenolics, minerals, caramels
 ...) which are fundamentally unfermentable.  It also contains many
carbohydrates (cellulose, gums limit dextrins) that can (almost) never be
made fermentable in the mash.  Then we have  non-limit dextrins which could
be made fermentable with the application of alpha-amylase(AA) or
beta-amylase(BA). It's good to keep in mind that a reasonably fermentable
wort, say over 77% apparent attenuation, has a *rough* breakdown of extract
as:
  63% in fermentables (and corresponding % real attenuation)
  28% carbohydrates (dextrins, caramels, gums, etc)
   9% non-carbos, protein, minerals,  etc

Down at the Bruteforce Chemical Brewery, if we want very high attenuation
for Atkinsian beers levels, we add amyloglucosidase enzymes either to the
mash or fermenter.   My local HB shop (grapeandgranery.com) special ordered
a bottle (about 1L) for about $35 (several ml/5gal, a lifetime supply).
Amyloglucosidase breaks amylopectin 1-6 bonds and converts many AA and BA
limit dextrins to fermentables.  When less "forceful" methods are sought we
have to consider the grist components and the mash schedule.

AA, with no help from BA, is capable of removing all starch and creating a
lot of fermentables and most grists have loads of AA.   AA acting on
conventional starch (20% amylase, 80 %amylopectin) may produce about 50%
fermentables.  So you should be able to get ~60% apparent attenuation from
AA alone.  The AA enzyme has a lower affinity to the short dextrins etc, so
this can take longer.

AA "prefers" a higher pH for "optimal" activity (pH=~5.8) while BA prefers a
low pH (5.1-ish).   Unfortunately the lower pH also makes BA less stable, so
dropping the pH is a losing strategy unless you drop the temp and increase
time radically.   The conventional mash pH 5.3-5.4 is a best compromise.
The change in activity vs pH is small.  You might lose 6-8% of BA activity
if the pH is 6.3 (far too high) !  pH is a *minor* but real factor in
fermentability and conventional pH is probably best and certainly good
enough.

Mash thickness is also a consideration. Both amylases are more stable in
thicker mashes where more starch (and even maltose) assist in substrate
stabilization. Unfortunately thick mashes also slow enzyme activity in the
early mash because the lack of free water.   If you mash much under 1qt/lb
of malt grist your mash is slowed by lack of water !  Thin mashes provide
plenty of water, but the enzymes are less stable and more damaged by temp
overshoots. Radically thin mash creates low substrate concentration which
slow the late mash progress.  Any thickness between 1.25qt/lb and up to
3.5qt/lb are feasible and practical.  Mashes on the thin side (2+qt/lb)
deliver higher extract and attenuation but part of the reason is related to
starch gelatinization and concentration(below).

Grist components contain variable levels of enzymes and particularly
beta-amylase which is primary to high attenuation.   A low kilned high
protein malt called distillers malt has very high levels of beta-amylase,
but should only be used in small quantity to avoid haze and flavor deficit.
Lager and pils malts are kilned at a lower temp than UK PA malts and have
therefore higher beta-amylase levels.  Munich malt has a kiln temp about as
high as PA malt and also has somewhat lower BA levels and AA levels and in
addition perhaps to a higher caramel unfermentable component.  Wheat and rye
malt can have very high amylase levels, but rye malts unevenly and it's
numbers are over the map.  Pale wheat malt often seems to have a notch
higher alpha-amylase levels than good lager malt, and even higher relative
BA levels too (based on the relation of AA measure vs Lintner degrees).
Adjunct (sugar, raw grain, starch) is nearly devoid of usable amylases.

The grist contains variable amount of easily extracted unfermentables.
Many raw grains have higher levels of unfermentable undegraded gums than
either wheat or barley malt. Some, like corn(maize), have very high lipid
levels and must be degermed to reduce high levels of oil.    Crystal&caramel
malts have high proportions of unfermentable caramel and relatively little
available starch.   I assume that an adjunct like candi sugar includes a
high proportion of fermentable sugar along with the unfermentable caramel -
(my guess).  Pure starch (or white flours) has perhaps 80% extractable
starch by weight, but the other 20% is largely insoluble. Adding a small
proportion (3-5% of extract) of cane sugar is a traditional UK ale method
that increases wort fermentability.  My point here is consider your grist as
part of the fermentability picture.  Sugar sources are 100% fermentable.
Most purified starches can modestly increase fermentability as they add only
to the carbohydrate mix (but detract from protein).  Most other adjuncts,
such as whole raw grain, poorly malted grain and anything with much
caramelized sugars are likely to detract from fermentability.

Ignoring the non-fermentables and also sugar adjuncts, sufficient enzymes
properly applied to starch is key to high fermentability.   One practical
problem is that two reactants (starch + water) and the catalyzing agent
(amylase enzymes) will not react rapidly as soon as the three are brought
together.   AA & BA appear primarily in the seed germ/endosperm barrier
layer and it takes a matter of 5-10 minutes to extract these in volume from
crushed malt (almost regardless of mash temp).  Starch isn't ready for much
hydrolysis either.  The amylopectin is tightly balled in granules with less
exposed surface, and these reside along with the amylose inside the remnants
of the (long dead and well degraded by malting) endosperm cells.  Of course
raw grain and flour adjunct has no malting degradation.  To access the
starches rapidly the cell walls must be breached and the amylopectin
granules unraveled - gelatinization.With raised temps first amylose leaks
out of the cells and the amylopectin granules swell.  The high fraction of
granules will burst very near to a characteristic temperature.  This
gelatinization temp(GT) is increased as sugars and starches are added which
may explain why barley GT is considerably lower than malt GT; malt
gelatinization includes more free sugar and starch.  A little calcium ion
content assists in gelatinization.

(more)-S



Return to table of contents


Date: Tue, 5 Apr 2005 00:48:37 -0400
From: "-S" <-s at adelphia.net>
Subject: Making highly fermentable wort(2/2)

Mash thickness impedes gelatinization slightly  so thinner mashes produce
marginally better extract yields (+2-3%) and potentially marginally higher
fermentability (as the addition extract is largely starch).   Mash thickness
can have another profound effect.   If you are familiar with using starch as
a cooking thickener, say adding flour to thicken gravy, then you are aware
of gelatinization and it's problem firsthand.  If the flour gelatinizes
before it is suspended in "enough" liquid then you have lumpy gravy.  If
instead you stir in the flour below the GT temp  then heat to above GT, the
gravy thickens smoothly w/o lumps.  The unraveled amylopectin absorbs and
traps considerable amounts of water and if sufficient water is unavailable
the "dry" amylopectins are likely to attach to each other and make a gluey
mess which is related to another day's topic called "starch retrogradation".
In gravy it's lumps, in the mash it's called "balling".  Retrograded starch
isn't digestible, can't be enzymatically degraded in any practical way.  You
should hydrate grist below it's specific gelatinization temperature to
prevent this.

In malt the alpha-amylase is incapable of curing the retrograded starch, but
it can prevent it from forming.   Anyone who has performed a cereal mash
understands that if you add a small amount of malt to crushed raw grain or
flour plus water and raise the temp above the gelatinization temp, that the
malt enzymes have a profound effect.  The cereal mash is much more fluid and
liquid than if no malt was added.  The malt AA snips the newly gelatinized
starch and this radically reduces it's demand for water (it's gelling
capacity).  This water is then available for use by other gelatinizing
granules.  So AA helps prevent retrogradation by increasing the available
water.  This probably explains why malt can be mashed with only 1.5X it
weight in water (0.75qt/lb) while text books suggest pure starch would
require 3-7X its weight in water to prevent retrogradation.

===============

Back to the practical impact:  How to make a highly fermentable wort with a
conventional mash & grist ?

1/ Grist Enzymes. Choose a grist that has sufficient BA as this is the
enzyme which carries wort from low attenuation to high.  PA malt and Munich
malt have insufficient BA enzymes to carry much starchy adjunct (unmalted
grain, flour, grits) to high attenuation.  Use lager malt, carefully chosen
pale wheat malt or some distiller's malt to carry adjunct starches to high
attenuation.

2/ Grist Starch & adjunct sugar. Only starch and sugars add to fermentables
so don't overload the grist bill with vast amounts of caramel, crystal
malts(adds caramel, not much starch) or other adjuncts high in
unfermentables.  [[Terry Foster's PA book uses 1.5 to 5.5% crystal, not the
10-15% I see in HB recipes]].  Do consider a modest cane sugar addition in
the boiler for a PA recipe - improves fermentability and is traditional.

3/  Choose a mash schedule & thickness which treats the BA enzyme carefully.
AA is plentiful and  stable while BA is in short supply and relatively
unstable.  Note that more than half the BA is lost in even a short (<1hr)
low temp (144F) mash so time & temp are both critical.  Also recall that the
enzymes aren't very available for 5-10 minutes after mash-in as they leach
from the grist.

4/ Expose the starch.  To get high attenuation we need *most* of the starch
in contact with the BA enzyme before it denatures.   Unfortunately barley
malt GT is higher (~150-154F) than our ideal high fermentabilty mash
temp(~144F) [wheat malt GT should be a bit lower].  Plan on a cereal mash
for substantial amount of starch adjunct ... absolutely necessary for high
GT grains like rice.   Avoid introducing starch late in the mash after the
BA is mostly gone.  All mash temp increases cause some starch release so
*consider* eliminating the mash-out (yes it's practical).

5/ Lautering and late runnings have less fermentables as a fraction of
extract so reduce or eliminate the sparge.

6/ Remember the goal is good beer, not max fermentability. You can't leave a
mash based on modern malts in the 55C-60C range for very long without
protein head & body loss.  Very long mash schedules may also compromise
flavor too.

Putting this all together, two alternatives are to bring the mash above GT
briefly and lower it back to the ideal BA rest temp *or* to make a short
rest near the BA ideal (which processes the cold water extract and a modest
amount of gelatinization at the near-GT-temp) then step the temp just above
GT before the BA is too far gone.

==
Wolfgang Kunze suggests the following *extreme* mash schedule for dietetic
beers (low dextrin) and suggests a 90-92% attenuation  is possible:
1/ mash-in 50C/122F 30 min
2/ 62C/144F rest 45 min
3/ 65C/149F rest 45 min
4/ 68C/154F rest 30 min
5/ 70C/158F rest 30 min
6/ 72C/162F rest 15 min
7/ mash-off 73-74C/165F.

Note that this is a ~3.5-4 hour long schedule.   Perhaps as Kunze is likely
to use lager malt with  more BA  he still persists in a third (4/)
saccharification rest hoping for more maltose but that's pretty iffy.  Any
further rests, I feel, are about allowing AA more time to degrade dextrins
and getting a little more extract (a commercial necessity).  Mash thickness
is not mentioned for this schedule, but is likely ~2-2.5qt/lb - his typical
for pale beers.

==
For pure-infusion brewing(insulated coolers) perhaps this would work well
enough
1/ mash-in very thick(0.5qt/lb)   at  50C/122F (hydration) 0-5 minutes.
2/ infusion step to 67C for full gelatinization rest for 10 minutes.
3/ downward infusion step to 63C for long BA rest - 45+ min.
4/ slow series of infusions to 68-72C over a 45min period.
 ...
I haven't done the infusion water equations, but I would hope the 67C rest
could be kept thick (around 1qt/lb) and the 63C rest should be thinned (no
chance of overshoot)  at 2-2.5qt/lb.

Here I expect the 0 time rest at 50C to just be long enough with just enough
water to avoid balling and the enzyme leaching to begin, and enzyme
extraction it will necessarily complete in a brief (thick to protect BA) 67C
rest where gelatinization should be completed.  The down-step rest to 63C
can be thin and the rest time can be extended ad nauseum.  The rising steps
(4/) are just window-dressing - allows AA to form some fermentables of
dextrins as the BA dwindles fast.

==
For a single infusion you'd probably be best-off compromising the BA losses
with the gelatinization temp and striking at around 65C/150F (which all
sounds oddly traditional)!

==

I used the Fix 50C-60C-70C rests early-on and got nice wort but medium-low
attenuation 72%-76% from memory).   I long-ago adapted this to
63C-72C-mashout which increases fermentability by several percent, but not
to Kunze-dietetic levels. I now see that the starch is too inaccessible at
60C (or even 63C) and any increase toward GT improves this.  The 60C rest is
too low to achieve gelatinization and too long avoid significant BA loss, so
it is not made for high-attenuation (which was not Fix's goal after all).
- --

One last point - don't be fooled by the numerology.  We speak of apparent
attenuation a tho' it's independent of other variables and it is not.  From
the discussion it should be clear that you can't simply doubleup the grist
and get the same attenuation at twice the Plato.   Most HB hydrometers and
measuring techniques give a 5%-ish percent error bound in apparent
attenuation measures - it's a crude tool for analyzing results.  Brew to
your preferred attenuation by taste not some mark on a paper.

 -SteveA



Return to table of contents


Date: Tue, 5 Apr 2005 01:17:13 -0400
From: "-S" <-s at adelphia.net>
Subject: re: Round two - Enzymes Next question

MARTIN AMMON shouts,

> Learning a lot but one question what happens when you throw in the fact
> that during the mash you are reticulating the wort from Mash to coil water
> tank back to Mash. Maintaining the set temps and clearing and  wort.

Depends on a lot of things,  The shear forces will denature enzymes (in the
pump and tubing) but apparently not at too high a rate (RIMS guys have used
these successfully for years).  I expect the impact of shear on starches is
negligible in their low concentration in the thin-mash.

Typical RIMS/HERMS operate by taking some thin mash through a heating cycle
and returning it to the big mash on a continuous basis.  Yes the enzymes
denature faster and act more rapidly at the raised temp in the tube, so you
need to keep the flow rate high enough so the hot returning mash isn't too
much hotter than the target temp.  In any case you can think of this as
keeping a fraction (whatever fraction of thin wort appears in the hot-side
tubing) of your enzymes at the higher temp with the corresponding
hyperdenaturing and hyperactivating rates.  The constant mixing means each
soluble enzymes is fractionally hyperdenaturing and hyperactivated, but some
fixed fraction.

There is little doubt that RIMS/HERM pumps and shear forces and excess
heating constitute a form of enzyme abuse, but there is an open question
about whether a RIMS/HERMS provides faster & better starch extraction or
product mixing to offset the enzyme abuse.  We'd have to compare the limit
of fermentability of wort from your masher(?) vs another method in a
ridiculously difficult to control experiment ... then we could say.

Can you make sufficiently fermentable wort for your needs ?   It's easy to
decrease fermentability I think so that's the only serious question at hand.

 -S




Return to table of contents


Date: Tue, 5 Apr 2005 18:47:04 +0200
From: "Fredrik" <carlsbergerensis at hotmail.com>
Subject: Re: Enzymes (extraction, half-lifes and location)

Thanks Steve for the nice enzyme posts. Good stuff!

There are some points that are somewhat cloudy for me and has 
been bugging me. I wonder if Steve or someone else has some
 more info on these details.

 -> impact of moist/water on the amylase decay rate

>From various posts on here, and brewing articles we have now decent 
ballpark data on the half lifes on both amylases in solution at different 
temps - so far so good. 

But to consider the extreme of a dry enzyme, trapped inside the dry 
grain, it is as far as I understand far more stable to heat than in 
dilution - right? 
(Otherwise I supposed the kilning would fry away more enzymes than
 they do.)

This raises the question how the half life curve looks, going from dry, 
increasing the moist, until it reaches full dilution in water? This means 
we have two datapoints, what does the curve looks like in between? It 
seems that during a slow liquification process, this might be a factor? 
Maybe not so easy to account for, but still.

What I am at, is that perhaps the not yet extracted enzymes (trapped in 
the not yet gelatinized starch matrix) doesn't decay as fast as we may 
expect assuming the same denaturation rates as in full dilution?

Any ideas? data?

 -> dynamics of enzyme extraction, physical location of enzymes

I would expect the above issue to apply mainly to the enzymes
scattered throughout the endosperm starch? Enzymes in the 
aleurone are I guess liquified relatively quickly. 

But as far as liquification of the endosperm, would it be a decent 
assumption to think that the % liquification correlated to % 
extraction of endosperm trapped enzymes?

I also ask this this because, at a typical predecoct rest, how many % 
of alpa rep beta enzymes have you actually extracted before toasted 
the rest in the boil?? 

>From what i've read, the endosperm is the bulk of the grain, though I've
 seen some reports that the beta-amylase density is somewhat 
higher in the embryo part this is still a minor % of the total deposit? I've
 also seem some claims that the outer layer of the endosperm and the 
aleurone later have higher enzyme density than the core sections, still I
 failed to find any numbers.I am also unsure if the distribution of alpha
 and beta are similar or not?

I would really like to get hold of some numbers on the above. They
might vary, but some ballpark numbers would be great. This 
seems to be part of hte key to the optimation process.

 /Fredrik



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Date: Tue, 5 Apr 2005 13:16:16 -0500
From: "Keith Lemcke" <klemcke at siebelinstitute.com>
Subject: Two Scholarships for Siebel Institute

The deadline for application to the 2005 Glen Hay Falconer Scholarships is
April 20, 2005, and we wanted to remind brewers to get their applications
in. The Glen Hay Falconer Foundation Brewing Scholarships consist of two
full-tuition scholarships for the World Brewing Academy Concise Course in
Brewing Technology held at the Siebel Institute of Technology in Chicago
(Oct. 31 - Nov. 11, 2005).

The Scholarships are open to professional brewers as well as homebrewers
from the Pacific Northwest (including Alaska and Hawaii) and Northern
California regions (San Francisco Bay/Monterey Bay areas and north). The
selection committee includes brewers and professionals related to the
brewing industry.

More information about the Glen Hay Falconer Foundation is available at
http://sasquatchbrewfest.org/ghff/ and for complete information about
applying for the Glen Hay Falconer Scholarships, visit the Siebel Institute
Scholarship web page at
http://www.siebelinstitute.com/registration/falconer_scholarship.html.



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Date: Tue, 05 Apr 2005 20:15:21 +0100
From: Signalbox Brewery <signalbox.brewery at ntlworld.com>
Subject: UK Yeast Event

Greetings to the other Brits

Chris White of White Labs has offered to give a technical talk to homebrewers
in the UK on Sunday 22nd May 2005.  It was thought a central location
would be best for this one off event.

We have made a provisional booking at The Lamp in Birmingham for that Sunday.
For a little insight to the pub please see CAMRA info
at  http://www.birminghamcamra.org.uk/Pubs.htm
Upmystreet gives a distance of 0.6 miles from New Street Station
Please see http://www.upmystreet.com/overview/?l1=B5+6AH

The start time is suggested as being 1.30pm.  There has been no discussion
about the end time.   This is a free event..

Would you please reply if you are interested in attending.
This invitation is open to all UK homebrewers and interested parties.
If there is sufficient interest within 7 days then we'll book both Chris
White and The Lamp. Please also suggest any other elements you think
we could include in the day - we're trying to make it worth your while to come.

If you feel passionately that the event should be held elsewhere and wish to
organise it, let me know as soon as possible.

I'll confirm the arrangements here.

David Edge



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Date: Tue, 5 Apr 2005 21:02:22 -0400
From: "Mark E. Hogenmiller" <mehogenmiller at cox.net>
Subject: Spirit of Free Beer XIII

Plan now to enter the Brewers United for Real Potable's (BURP) Thirteenth
Annual Spirit of Free Beer (SoFB)competition.

 - -- The deadline for entries to be submitted is May 6th, 2005. So get your
systems brewing!

 - -- The competition will be held on Saturday May 14th at the Old Dominion
Brewing Company in Ashburn, Virginia.

The Details

The SoFB competition is open to all homebrewers and will judge all BJCP/AHA
sanctioned styles including Meads and Ciders.  The SoFB competition is
judged by experienced BJCP certified judges.  The SoFB prides itself on the
quality of the comments made and prizes that are awarded.

Questions can be addressed to  sofborganizer at earthlink.net

Information is now available on the Spirit of Free Beer website at
http://www.burp.org/events/sofb/2005/

Mark Hogenmiller
BURP Minister of Culture 



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