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HOMEBREW Digest #2708
HOMEBREW Digest #2708 Fri 08 May 1998
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
Digest Janitor: janitor@hbd.org
Many thanks to the Observer & Eccentric Newspapers of
Livonia, Michigan for sponsoring the Homebrew Digest.
URL: http://www.oeonline.com
Contents:
pH Experiment - Background ("A. J. deLange")
pH Experiment - Procedure ("A. J. deLange")
pH Experiment - Data Sheet ("A. J. deLange")
Oatmeal Stout / Wisconsin Homebrew Clubs (Matthew Arnold)
Hop Farming (Kevin TenBrink)
Stout head retention (John Coulter)
Is my malt ruined? ("George De Piro")
DO and mixing (Hugh Hoover)
FWH extract recipes (Kevin TenBrink)
Stainless Conical Fermenter ("S. Wesley")
Acetaldhyde ("David R. Burley")
SABCO mash kettle info wanted (Bill Holman)
Dryhopping (Jeff Renner)
South African Homebrewers ("Dallas Dahms")
Evaporation Rates ("Henckler, Andrew")
Boiling and evaporation rates (George_De_Piro)
Boil rates and evaporation (michael rose)
Covering the boil (Charles Hudak)
Beer Evaluation (George_De_Piro)
Trip from NYC to GABF in Baltimore (BR Rolya)
Boil evaporation (Troy Hager)
10% rule (Jeremy Bergsman)
Re: Re-started fermentation in the secondary (brian_dixon)
BURP's Spirit of Free Beer competition is June 6-7 and entry information
is available by contacting Jay Adams (adams@burp.org).
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----------------------------------------------------------------------
Date: Wed, 06 May 1998 16:50:35 -0500
From: "A. J. deLange" <ajdel@mindspring.com>
Subject: pH Experiment - Background
Background:
About a week or so ago I posted concerning quantifying the extent to
which mash pH changes with temperature. Many books and articles say that
brewers who cool their wort should subtract 0.3 units from a room
temperature pH measurement to compensate for the fact that the
measurement is being made cold. This number seems to derive from a table
in DeClerk (who in turn got it from Hopkins and Krause, "Biochemistry
Applied to Malting and Brewing", London, 1950). The table shows measured
pH vs. the temperature of measurement for two mashes: one made with
distilled water and one with "medium hard water". While the pH values
differ for the two mashes both sets of data show a trend of very close
to .004 pH per degree F.
I mentioned that I usually see a rise of only 0.1 pH unit but
consultation of my notes shows that it is more like .13 - .15 or about
half what DeClerk's data show. I wondered whether this is yet another
example of widely accepted misinformation circulating and recirculating
throughout our community. This caught the eye of Lewis Bonham who is,
as you know, doing a column in BT whose focus is experimentation in
brewing. This is just the kind of data he'd like to have and I'd love to
provide it. There is, of course, a catch. I may have a much better pH
meter than Jan DeClerk ever saw in his lifetime of brewing research but
I don't have the lifetime to devote to brewing reasearch (alas).
Therefore, I can only accumulate a limited amount of data in reasonable
time and that's why I'm asking for input from other brewers. If some of
you will will pitch in we ought to be able to accumulate a fairly broad
base of data. I think this is a neat opportunity for the collective (as
we so often call outselves) to do something collectively.
There is, of course, a catch here too and that is that differences in
equipment and difference in technique may distort the data. I can't do
"quality control" if I'm not there but what I can try to do is lay out a
procedure which we'll hope will give consistent results when used by
anyone with appropriate equipment. This procedure is little different
from what is regarded as good practice but what we'll do is define a
particular set of steps and ask that contributors adhere to them even
though their equally good practices may differ somewhat. I will also ask
that participants furnish raw millivolt readings in addition to pH
readings. In this way I can see what shape your electrode is in and the
raw data lets me do "calibration" and temperature compensation myself
so that all data will be based on the same algorithm. I put
"calibration" in quotes because it's a bit of a misnomer. What we are
really doing is using the assumption that a pH electrode's output
voltage (whatever shape it is in) reponds linearly to changes in pH and
temperature and then comparing (really interpolating) voltage and
temperature readings for the test solution (mash) to the known pH's of
two buffer solutions.
Here's a tentative "protocol" for this experiment. Don't just leap in
and start measuring yet (unless you really want to) but rather let's let
a little time go by to let interested parties (i.e. potential
participants) comment on or question what I've proposed. If you think
you would like to participate, please drop me a line and describe your
meter and electrode.
Required Equipment:
Electrode: There are a couple of requirements for the electrode. First,
it must be able to withstand the heat of the mash (electrodes
containing calomel will be destroyed at about 70 C (158 F)). Second, its
filling solution should only contain potassium chloride (in particular
it should not be the commonly used potassium chloride plus silver
chloride). Silver can react with the proteins in beer and can cause
reading errors.
Meter: There are lots of meters available and lots of combinations of
features. To put all contributors on an equal footing irrespective of
meter "bells and whistles" for this experiment we want only the ability
to read millivolts and nearly all meters have this capability. It is
desireable that the meter read to 0.1 mV as this corresponds to
nominally 0.0016 pH. Another important feature is that the meter's input
impedance be high relative to the electrode's resistance. It may be
difficult to determine the input impedance of your meter as not all
manufacturers put that number in their spec sheets.
Buffers: Buffers should be NIST traceable and certified to within plus
or minus
0.02 pH. I've used this spec since most buffers you can buy meet this.
pH 7
and pH 4 buffers are required and should be made up fresh with deionized
water before each brew session unless pre-mixed buffers are used.
Pre-mixed buffers will preferrably be those which are sold in individual
pouches. Bottled pre mixed buffers should be new and particular care
must have been taken that pH 7 buffer has not been contaminated with pH
4 buffer (and vice versa) as by failure to rinse the electrode when
moving it from one buffer to another. The integrity of the buffers is
absolutely essential to the success of the experiment. The two buffers
are the ends of a pH "ruler" and pH measurements made with bad buffers
will be as worthless as distance measurements made with a yardstick
which is several inches too long or short.
Thermometer: A good thermometer readable to 1 degree (Fahrenheit or
centigrate) is required to measure the temperature of buffers and
samples. The temperature sensors built into pH electrodes are OK.
Wash bottle: This is ideally a squirt bottle filled with deionized water
which is used to wash off the electrode and thermometer (if it is
separate from the electrode) each time the electrode is put into a new
buffer or test solution. If a squirt bottle isn't available, put some
distilled water (about a buck a gallon from the drug store) in a glass
and dunk the electrode. Discard this rinse, rinse the glass with a small
additional amount of distilled water, and then refill it with more
distilled water for the next rinse.
Beaker or glass: This is the container into which you will fill the mash
test sample. It should hold enough mash that it will not coll so quickly
that you can't get a temperature stable reading.
-MORE-
------------------------------
Date: Wed, 06 May 1998 16:52:42 -0500
From: "A. J. deLange" <ajdel@mindspring.com>
Subject: pH Experiment - Procedure
Procedure
Here are the steps in the procedure. Data should be reported on the data
sheet which is in a nearby posting.
1. Prepare fresh buffers or let pre-prepared buffers come to room
temperature.
2. Calibrate your meter using the manufacturer's instructions. This
involves putting the electrode into each of the buffers in succession.
Be sure to rinse off any storage solution before entering the first
buffer and then rinse the first buffer before going into the second.
Shake or blot rinse (don't wipe) water.
3. After calibration (or as part of it if your meter allows) measure and
record (on the data sheet) buffer temperature and millivolt readings for
each of the two buffers. Be sure buffer millivolt readings are stable
before recording.
4. Measure the pH of the water you are brewing with and enter the
reading on the data sheet..
5. If you know the alkalinity and hardnesses of the brewing water report
that data on the data sheet. If calcium and magnesium hardness are known
separately report total hardness. Specify whether hardness data is "as
calcium", "as magnesium" or "as calcium carbonate".
6. Record grist composition i.e. how much of each grain type. Give
maltster, and specify type e.g. Paul's Crystal, 50 L 1 lb.
7. Measure pH at one or more points in the mashing process. Wait a few
minutes after doing things like doughing in or returning a decoction.
Use a separate data sheet for each set of measurements. Start by
withdrawing a few hundred mL of mash in a glass or beaker.
8. Rinse the pH electrode and thermometer and insert into the mash.
Monitor the mV reading.
9. Move the electrode slowly and uniformly through the mash while
watching the mV reading. IT MUST BE STABLE. When the reading is stable
record it and then switch the meter to pH mode. Record the pH reading.
Record the thermometer reading (make sure it is only touching the mash
and not the beaker or glass).
10. Cool the mash sample as by placing the beaker in cold water. After a
few minutes, stir the sample thoroughly and check its temperature. Try
to get a handful of temperatures between mash temperature and room
temperature. We'd like at least 3 and 4 or 5 are better still.
11. Repeat from Step 9 until room temperature is reached.
12. Thoroughly rinse the mash from the electrode and thermometer and
then measure mV and temperature of the two buffers again being sure to
rise before moving from one buffer to the other. Record the results on
the data sheet. If you are going to do another set of measurments at a
later stage in the mash, don't repeat the buffer measurements at the
beginning of the new measurement set unless more than an hour has
passed.
-More-
------------------------------
Date: Wed, 06 May 1998 17:01:14 -0500
From: "A. J. deLange" <ajdel@mindspring.com>
Subject: pH Experiment - Data Sheet
Data should be reported on this data sheet for consistency. Copy and
paste a copy of the data sheet for each set of measurments you report.
For example, if you do pH measurements at the return of the 1st and
second decoctions use a separate sheet for each of those sets of
measurments.
Style of Beer: Length:
Grist Composition:
WATER
Source; treatment:
pH:
Alkalinity:
Hardness Total: Calcium : Magnesium:
pH Meter Make: Model:
Electrode Make: Model:
Age:
BUFFERS
Manufacturer:
Form (i.e. pouch, pre-mixed...):
pH 4 Buffer pH 7 Buffer
Temp.: milliVolts: Temp.:
milliVolts:
Temp.: milliVolts: Temp.:
milliVolts:
Mash Step (e.g. single infustion rest, after return of 1st decoction):
Temp.: millVolts: pH:
Temp.: millVolts: pH:
Temp.: millVolts: pH:
Temp.: millVolts: pH:
Temp.: millVolts: pH:
Temp.: millVolts: pH:
pH 4 Buffer pH 7 Buffer
Temp.: milliVolts Temp.: milliVolts:
Temp.: milliVolts: Temp.: milliVolts:
------------------------------
Date: Wed, 06 May 1998 23:40:29 GMT
From: marnold@netnet.net (Matthew Arnold)
Subject: Oatmeal Stout / Wisconsin Homebrew Clubs
Seeing as things are kind of slow on ye olde HBD, I thought I'd ask these
questions. I'm planning on making an Oatmeal Stout with 7 lbs pale ale, 1 lb
Roasted barley and 1/2# oatmeal. Is this enough to give me that nice sliky
smoothness? How much more dare I add before I need a beta-glucan rest? 1/2# in
this recipe = ~6% of the grist.
- -----
Attention Wisconsin Homebrew Club members! I'm trying to get a listing of all
the WI clubs on our website (see address in my .sig). Check out our listing at
http://www.rackers.org/clubs.html I've only found three others (Madison
Homebrewers and Tasters Guild, Sin City Sudzzers, and Washington Heights
Brewery) so far. I'd also like to look into the possibility of a WI club
alliance of some sort (we tossed this idea around for a while at a recent
meeting. What do you think?
Thanks,
Matt
- -----
Webmaster, Green Bay Rackers Homebrewers' Club
http://www.rackers.org info@rackers.org
------------------------------
Date: Wed, 06 May 1998 19:04:32 -0600
From: Kevin TenBrink <tenbrink@jps.net>
Subject: Hop Farming
Hello-
I have a question for all the home hop farmers out there.
I have some 2nd year vines in the ground that are doing quite
well....almost 12 feet long already! My questions are:
1) I keep getting little hop shoots sprouting out of the ground, some
as far away as 3 feet from the original planting area. I keep cutting
these back but I am wondering if they will ever stop sprouting or if
there is something I can do to make them stop sprouting.
2) There is a chance I may be moving this summer from Utah to MI.
Can I dig up and take a root cutting in the middle of the summer and
replant when I arrive in MI to start establishing the root base for next
year?
Thanks--
Kevin
Nine Inch Ales Homebrew Club
Salt Lake City
http://www.jps.net/tenbrink/nineinchales.htm
------------------------------
Date: Thu, 07 May 1998 10:59:38 +1000
From: John Coulter <jac@mira.net>
Subject: Stout head retention
As a long time lurker, and Aussie home brewer, I need some help from the
experts. My Guinness style stout, made with extract and steeped
flaked/roast barley tastes and looks just the way I like it...almost. My
nitrogen/co2 mix keg set-up and stout faucet pours a fine head, a bit
foamy at times, which eventually results in a half inch head, looks
perfect but then it disappears within five minutes, and doesn't taste as
thick/creamy as a well poured guinness.
I've tried doing a protein rest for the flaked barley, adding pale malt
grain but it didn't help. Tried adding wheat to partial mash and that
didn't either.
My questions are:
1. Could using bleach steriliser be a contributor? ( I rinse 2 or 3
times)
2. Will using a carbonation stone, as someone suggested, increase the
amount of nitrogen dissolved, and provide smaller bubbles to keep the
head alive. Does anyone know if Guinness nitrogenate their kegs before
they ship them or only use it to serve?
3. Have I reached the limits of extract brewing and can only improve the
head by going to full-grain?
4. Does the quality/grain size of the flaked barley make much
difference?
5. Any other ideas/suggestions?
BTW the digest's great. I went from being an unhappy kit brewer to an
almost happy, perfectionist, extract brewer with a laundry full of kegs,
gas tanks and a hole in my pocket.
Private E-mail fine.
John Coulter
jac@mira.net
------------------------------
Date: Wed, 06 May 98 21:24:56 PDT
From: "George De Piro" <gdepiro@fcc.net>
Subject: Is my malt ruined?
Hi all,
I'm just finishing up a 1.5 week home malting project. I've made
Pilsner, light and dark crystal, and Munich malts. Some chocolate malt will be
made from the Munich malt in the very near future.
All of the malts taste good, except for the Munich malt. It was also the
most challenging to make, so it is no surprise that the outcome seems
less than stellar. It has a quite pronounced acrid taste in the finish.
It smells sweet and malty, but a bit too toasty. The color is a touch
darker than Weissheimer Munich malt, too.
I know, it seems an easy diagnosis: I over kilned it in the final
stages. Of course it isn't that easy, though. I actually kilned it cooler and
shorter than recomended by Kunze. Could it be the uneven heating in
my oven? Is it that young Munich malt is supposed to taste a bit rough?
Is my malt ruined?!
If you haven't tried home malting, you don't know the fun your missing.
I really enjoyed getting up at 2 am to check on the malt in the oven!
You really develop an understanding of the whole process, too. For
those who may be intimidated, Pilsner and crystal malt are actually pretty
easy to make. If you are ever really searching for something to do, give
it a shot!
In the old days, crystal malt was made by steeping finished pale malt
until a moisture content of ~45% was reached. You should change the steep
water quite often to avoid souring of the malt if you do it this way
(lest you make acid malt). Once the malt is appropriately wet, you cover it
and heat it to as close to 145-160F as you can to saccharify it (just
like mashing). After a couple of hours it will be noticeably sweet and
somewhat darker (keep an eye on it if you are trying to make light crystal).
You can then uncover it, let it dry, and raise the temp anywhere from
170F to 350F to make the color crystal you want and dry the malt. Easy!
Have fun!
George De Piro (Nyack, NY)
------------------------------
Date: Wed, 6 May 1998 18:38:09 -0700
From: Hugh.Hoover@software.com (Hugh Hoover)
Subject: DO and mixing
While cursing my empty O2 container, and thankful that
I'd sanitized my aquarium stone, I was thinking about
the aeration process. Most of the actual transfer
of gas into the liquid happens at the bubble interface
(I think), which mostly is in the foam on top...
This makes me think that for effective aeration, the
wort has to be mixed during the aeration.
I've observed that when using air (and 30 mins of
aeration) I get pretty good starts, but w/ O2 (~2 min),
sometimes I don't. Makes me think I should mix when
using O2 (or use an inline stone).
The airstone appears to put out sufficient volume
to cause some mixing in the primary, plus working for
30 mins probably gives it time to set up a mixing
pattern.
Anybody done any testing of DO vs mixed / not mixed?
Also, what's a reasonably volume of 02?
Hugh Hoover
PetaPint Brewery
------------------------------
Date: Wed, 06 May 1998 19:22:11 -0600
From: Kevin TenBrink <tenbrink@jps.net>
Subject: FWH extract recipes
A question regarding FWHing extract with specialty grain recipes.
If I want to try this, do I add the flavor and/or aroma hops to the
sparged specialty grain soak water as I am bringing it to a boil but
before I have added the extract? Do I remove the hops as the wort
starts to boil or leave em in the whole time?
Thanks for the help
Kevin
Salt Lake City
------------------------------
Date: Thu, 07 May 1998 06:28:33 -0700
From: "S. Wesley" <Wesley@maine.maine.edu>
Subject: Stainless Conical Fermenter
Dear Jim,
You may be able to purchase small cylindroconical fermenters from
Pierre Rajotte's Company. I don't remember the name off hand, but I've
seen a number of his 2 barrel fermenters in use in small breweries and
I've heard that he makes smaller ones. If you can find a copy of this
month's "American Brewer" Magazine he has an article on continuous
fermentation in which he mentions the name of the company. Sticker shock
may be a problem, so here is an alternative.
I've been using 20 gal plastic barrels as fermenters for a while
now with good results. I bought about ten of them from Modern Brewer in
Boston for $19 each. They had been using them as fermenters in their
commercial brewing operation. Unfortunately I belive they sold out of
them when they sold off their BOP equipment, but they are not too hard to
come by. Lots of people in Maine use them to collect sap for maple syrup
manufacture. One guy told me he gets his used from dairy farmers,
apparently they originally contained "teat dip"! Just last night I was
driving home from work and I saw a few sitting by the side of the road.
The guy who was throwing them away brought them home empty from the local
hosptial where they originally contained an instrument sterilizer. You
may also be able to find them at places like Grainger or McMaster-Carr.
The fermenters have two 2.5" threaded openings in the top and a
double handle which is rugged enough to lift the fermenter safely when it
is full, although, they are, of course, rather heavy. They come with
caps which have a rubber gasket which forms an air tight seal when
screwed in properly. The caps can be drilled out to accomodate whatever
gas release you want to use.
I've rigged up a pulley system in the basement to lift the
fermenters gently into the air for transferring. A racking cane made out
of .5" copper tubing bent into a J at the top and bottom allows for
surprisingly rapid transfer without the hassle of sanitizing pumps, or
the accompanying agitation and loss of CO2.
Regards,
Simon A. Wesley
------------------------------
Date: Thu, 7 May 1998 07:57:35 -0400
From: "David R. Burley" <Dave_Burley@compuserve.com>
Subject: Acetaldhyde
Brewsters:
AJ DeLAnge gives a fine dissertation on the thermodynamics of alcohol
oxidation using the Nernst equation. Nernst of course assumes there is
an
equilibrium situation. In the absence of that assumption, it is not
correct that the higher the voltage, the more product you get. In the
world
of kinetics if you get a product and there is no back reaction, one only
needs to get over the hump to form product permanently, so a minimum
potential energy ("forward voltage") is all that is needed.
Also, acetaldehyde is a major component in sherry along with lots of
other
aldehydes. Acetaldhyde is largely responsible for the disappearance of
the
anthocyanins from red wines used to make sherry as the acetaldehyde
formed
by the air oxidation of alcohol. Acetaldehyde reacts with the
anthocyanins
and the complex precipitates. Acetaldehyde also reacts with ethanol to
produce an acetal. As sherry ages other aldehydes such as
iso-valeraldehyde
and higher molecular weight ones come forth and produce the classic
aromas
and taste, but acetaldehyde is still there and is a major taste
contributor. Perhaps in low concentrations acetaldehyde in Budweiser
tastes
like green apples.
- --------------------------------------------
Keep on brewin'
Dave Burley
Kinnelon, NJ 07405
103164.3202@compuserve.com
Dave_Burley@compuserve.com
Voice e-mail OK
------------------------------
Date: Thu, 7 May 1998 08:04:49 -0400
From: Bill Holman <jwh7k@avery.med.virginia.edu>
Subject: SABCO mash kettle info wanted
I would like some info from users of the Sabco mash kettle.
How is the perforated stainless steel false bottom supported, ie how
is it kept off the rounded keg bottom? Has anyone had the false bottom
collapse from the weight of the grains/water or from use in a RIMS system?
Overall, have you been happy with the kettle. Any comments or criticism
would be helpful. Post answers to this newgroup or email me.
Thanks!
------------------------------
Date: Thu, 7 May 1998 09:34:33 -0400
From: Jeff Renner <nerenner@umich.edu>
Subject: Dryhopping
"Kris Jacobs" <jtsnake@mail.net-link.net> wrote:
>I dropped two EKG plugs into each keg. Now, of course, I
>get hop particles out my tap into my glass.
First off, Kris, you used a whole lot of hops. Those 1/2 oz. plugs were
originally designed to dryhop a cask of beer, although I can't recall
exactly which of the many English sizes that was (certainly bigger than 5
gal.US). I've also read of an old brewery that used one handful of hops
per cask, and it was specified that this was the hand of a small woman.
They would stuff them in the bunghole using a stick and funnel. The hops
do settle out and only an occasional leaf will come through at this lower
rate, but as you point out, this is an annoyance, and they can even clog
the tap. Much better to use a hop bag, but, as you suggested, it's too
late for that.
Rather than transfer the beer, I'd suggest getting a couple of stainless
pot scrubbers, boil or otherwise sanitize them, remove the dip tubes of
your kegs and tie the scrubbies on the ends of the tubes. This should
filter the hops pretty effectively without clogging. Then get set for some
pretty powerful dry hop character as time passes.
Jeff
-=-=-=-=-
Jeff Renner in Ann Arbor, Michigan c/o nerenner@umich.edu
"One never knows, do one?" Fats Waller, American Musician, 1904-1943.
------------------------------
Date: Thu, 7 May 1998 15:32:33 +0200
From: "Dallas Dahms" <ddahms@nbs.co.za>
Subject: South African Homebrewers
I am looking for somebody who is a home brewer, living in SA who will be
able to assist me and my Father in our search for the right equipment to
start our own home brewing.
If you are able to help me out, I would really appreciate it.
Many thanks
Dallas
------------------------------
Date: Thu, 7 May 1998 10:13:34 -0400
From: "Henckler, Andrew" <ahenckler@findsvp.com>
Subject: Evaporation Rates
>Date: Wed, 6 May 1998 16:23:32 -0400
>From: dbgrowler@juno.com
>Subject: kettle evap rates
>
>Troy brings up issues that have caused some serious navel gazing here
in
>my brewery. For many years, I happily boiled the bejesus out of my
wort,
>7 gal down to 5.5 over 90 minutes, enjoying my high alpha utilization,
>excellent kettle break, and award-winning finished beer. After reading
An
>Analysis of Brewing Techniques, I, too, started worrying. I asked
several
>professional brewers about it; I can summarize their replies as "I
>dunno." Then I went back and looked at my logbook. Though I brew plenty
>of beers of all types and colors, the medal- and ribbon-winners were
all
>dark beers. Hmm. Reviewing score sheets on lighter beers showed some
>indefinite remarks like "watch sanitation" with no specific off-flavor
>mentioned, incorrect guesses at the yeast strain used, fermentation
>temps, pitching rates, etc., which is quite in line with Dr. Fix's
>observations. It appears that the effects of excessive thermal stress
are
>subtle for my system, such that they are not noticeable (or more in
line
>with the flavor profile) in the heavier, maltier beers. I've since
brewed
>two light Munichs serially, the second one with a less vigorous boil,
but
>otherwise unchanged. The results? I dunno... A partially covered boil
>could be the ticket, but I foresee a learning curve perfumed with the
>acrid smell of caramelized sugar. I think the key phrase in Fix's book
is
>"find a balance"; balance between adequate kettle reactions and thermal
>stress, and also between attention to detail and a relaxed mental
>attitude.
>
>Mike Bardallis
Hello to all, especially Mike:
I think that a more tightly controlled experiment might be in order
here, unless Mr. Fix or some of our resident experts can give us some
solid grounds for concern over evaporation rates (come on George de
Piro, whip out those nice Siebel textbooks). Lighter beers are tougher
to brew well because everything stands out. That means if you had only
a tiny bit of difference in your bacterial counts, etc., the flavor
could be noticeably different between batches, thereby confounding any
attempts to see differences in thermal loading effects. You will also
get different hop utilization, protein coagulation, etc. between a
lightly boiled and heavily boiled batch, so it will be tough to compare
two batches for thermal loading effects, ceterus paribus.
As a highly anecdotal side-note, I use an afterburner style cooker with
90 to 120 min. boils even on lighter beers and my lighter beers actually
tend to do better in competitions than the darker ones.
Happy boiling!
Andrew P. Henckler
Senior Research Analyst
Industrial Products & Services Practice
Strategic Consulting & Research Group
FIND/SVP-THE BEST PEOPLE TO FIND THE ANSWERS
625 Avenue of the Americas
New York, NY 10011
Tel: (212) 807-2754
Fax: (212) 807-2782
E-mail: ahenckler@findsvp.com
Web: http://www.findsvp.com
------------------------------
Date: Thu, 7 May 1998 10:22:12 -0700
From: George_De_Piro@berlex.com
Subject: Boiling and evaporation rates
Hi all,
Regarding kettle evaporation rates > 10% per hour, Troy writes,
quoting Scott:
"This is a typical Fix'ism; he makes a statement and then
backs it up with nothing. The only negative from a stronger boil that
I can think of is a greater energy ($$) usage."
Talk about saying things without having anything to back it up!
However, Scott is partly correct: higher energy costs are one big
reason for keeping boiling times short. There are others, though,
that are very important:
1. Caramelization and darkening of the wort are NOT always purposes
of boiling! There are many styles of beer where this is detrimental
(any pale beer). In fact, a major advantage of high-temp, pressure
boiling is that the boil time can be *greatly* reduced, thus
minimizing the amount of wort darkening that occurs. Hot break
formation and alpha acid isomerization occur in 3-5 minutes at
temperatures around 145C (293F). (That's not a misprint; three to five
minutes.)
The caramel flavors produced in the kettle are not appropriate in
light beers, and may be what Fix is talking about. This fits nicely
with Mike's experience (his dark beers taste better than his light
beers given the same boil parameters).
2. If you have to boil off 20% of your wort to reach your target
gravity, you may be oversparging. While you may be realizing great
mash efficiencies this way, you may be negatively impacting the flavor
of your beer because of increased phenol extraction during the sparge.
This could cause astringency in the final product, and some beer
evaluators may attribute it to a sanitation problem.
Commercial brewers, with their concerns about efficiency and $$$, will
sacrifice some extract rather than spend a fortune in time and $$$
boiling all that extra water off.
3. Too long of a boil can actually cause hot break to redissolve into
the wort, or break it up into smaller flocs that are more difficult to
remove. Neither situation is desirable.
4. Too long/intense a boil can actually cause sugars to revert back
to their starchy origins! I'm not sure how long of a boil that would
take, but Dr. Powers at Siebel mentioned this. Anybody care to talk
about how long this would take?
So, there are some solid reasons to avoid overly long and/or intense
boils. I'd like to hear some more, particularly from Dr. Fix.
Have fun!
George De Piro (Nyack, NY)
------------------------------
Date: Thu, 07 May 1998 07:55:59 -0700
From: michael rose <mrose@ucr.campus.mci.net>
Subject: Boil rates and evaporation
There has been a lot of discussion lately about boiling and rates of
evaporation. i.e. comparing a partially covered home kettle to a pro's
domed shaped kettle. The pro's have a blower (don't know the technical
term for it) on top of the flue. The blower exhausts the steam from the
kettle but it also creates a slight lowering of the air pressure which
increases the rate of evaporation. I think. Anyway, I'm sure the blower
interacts in many more ways than we are taking into consideration. I
think :^)
- --
Michael Rose Riverside, CA mrose@ucr.campus.mci.net
------------------------------
Date: Thu, 07 May 1998 08:01:54 -0700
From: Charles Hudak <cwhudak@adnc.com>
Subject: Covering the boil
Regarding covering the boil.....
"Professional" kettles are not really "covered". I'm assuming that you are
referring to the 'onion dome' on top of the kettles which channels the
steam and other volatiles out of the building. This is so the humidity
level doesn't go through the roof in the brewhouse. Usually there is active
ventilation (a blower on the roof) which ensures that the steam goes up the
stack and not out the manway. This actually increases the rate of
evaporation somewhat.
I don't see any reason to try to achieve an evaporation level of exactly
10%. My advice is to keep track of your brewhouse parameters so that you
know what your evaporation loss is and adjust your recipes and your runoff
volume accordingly. That is what the "Pros" do. They have no (or very
little) control over evaporation losses. They is what they is.
FWIW, I am no longer a "Pro". On Friday, I reverted to amateur status. Got
a job offer that I couldn't refuse: lots more $$, great benefits, quality
oriented....all the things missing from my beermeistership. Hey, now I can
afford to buy that pico system and start doing lots more
homebrewing..."Kick ass"
L8rz
C-
------------------------------
Date: Thu, 7 May 1998 11:14:00 -0700
From: George_De_Piro@berlex.com
Subject: Beer Evaluation
Hi all,
Capt. Marc asks about what will happen to his beer when he sends it to
a contest. He wonders if he will get feedback even if he doesn't
place, and is concerned about proper handling and serving of his beer.
When your beer arrives at the contest shipping point, it should be
stored in a cool, dark place. Most people try to run good contests,
but there are always exceptions. I heard about a recent contest where
the beers were stored outdoors in the winter sun. That's a big
"Oops!"
The day of the contest the beers are brought to the contest location
(if they are not already there) and served to the judging panels,
which each consist of 2 or 3 evaluators. The beers are broken up into
flights depending on the style of beer and the number of entries.
Very often stouts are broken into two or more flights (evaluated by 2
or more panels) because there are so many entered. Conversely,
Vienna, Oktoberfest, and Alt are often lumped into one flight. In
this way an attempt is made to give each panel a reasonable number of
beers. Overloading the judges only reduces the quality of their
feedback because of palate fatigue and time constraints.
The beers may be served too warm or too cold, but rarely "just right."
I often carry a cooler with me that I can fill with hot water to warm
up freezing-cold samples. It is easier to evaluate a beer that is too
warm than too cold. I don't think there are many judges this anal,
though (which is unfortunate).
The evaluators fill out a score sheet for every entry, and the
participant will receive these in the mail whether or not they placed.
The judges should not talk about the beer until all comments are
written. This way, one judge cannot influence anothers perceptions.
That is why you will sometimes get sheets back where it seems like the
judges were tasting two different beers; we're all human, and some
people are more sensitive to some chemicals than others.
The usefulness of the judge's comments is dependent on the quality of
the evaluator and the contest organizer. It is up to the organizer to
take care of the following: Is the beer served at close to the proper
temperature? Is the right beer being served in the category it was
entered in? Are there enough judges to handle the number of entries?
Is the beer stored properly prior to the contest?
It is up to the judge to prevent palate fatigue by drinking plenty of
water and taking small sips of the sample. Sobriety is key! Bread
should not be used as a palate cleanser; it has taste and aroma!!!
The starch in the bread can actually clog the larger taste buds at the
back of your tongue (the bitterness receptors).
I recently judged at a professional competition at the Culinary
Institute of America. They put big baskets of wonderful, crusty,
buttery-smelling bread on each table. Another big oops!
Have fun!
George De Piro (Nyack, NY)
------------------------------
Date: Thu, 7 May 1998 12:04:30 -0400 (EDT)
From: BR Rolya <brrolya@cs.columbia.edu>
Subject: Trip from NYC to GABF in Baltimore
The following is a region-specific post; I apologize in advance for its
limited appeal.
On Saturday, May 16, the Malted Barley Appreciation Society (a NYC
homebrewing club) is renting a bus to go down to the Great American Beer
Festival in Baltimore. We will leave Manhattan at 6:45 AM and arrive in
Baltimore in time for the 12:30 pm session. We will leave Baltimore at
around 8:30 pm.
The cost is $30 for round-trip bus fare. In addition, you must purchase
your own ticket for the GABF from the AHA (tel. 888-822-6273) for $25.
AHA members can also request a voucher for the members-only session that
begins at 11 am (we will arrive in time for that).
As an added attraction, we will premiering the infamous "Steinbier
Incident" video starring George de Piro and directed by Bill Coleman!
For more information, or to reserve your seat, contact Bob or myself at
212-989-4545 or triage@mindspring.com
- BR Rolya
Triage
brrolya@cs.columbia.edu
------------------------------
Date: Thu, 7 May 1998 20:40:09 -0700
From: Troy Hager <thager@bsd.k12.ca.us>
Subject: Boil evaporation
Tony,
You say:
Another solution would be to add boiling water to the kettle to keep the
wort level at the desired level. i.e. 5.5 Gallon initial vol. then add
boiling water when the level drops below 5 Gallons.
___________________
I don't know if this is a solution. What Fix is discussing in their book is
the negative effects of excess thermal loading, not of excess loss of
water. I think they are saying that the evaporation rate (loss of water)
itself is not the problem(though a good reference) - it is the excess heat
and all of the ramifications of this to the boiling wort that is the cause
of negative affects...
Troy A. Hager
2385 Trousdale Drive.
Burlingame, CA 94010
259-3850
------------------------------
Date: Thu, 07 May 1998 09:39:32 -0700
From: Jeremy Bergsman <jeremybb@leland.Stanford.EDU>
Subject: 10% rule
Regarding the discussion about evaporation rates:
I don't have the Fix book in front of me but I recall that when
Fix mentions that evaporation should be <15% it is int he context
of a discussion of heterocyclic sulfur compounds, no? If you look
at the flavor descriptions of these, many are undesirable. I believe
that you want to limit formation of these and that is why you want
to limit "thermal loading."
As another data point I don't feel my boils are all that vigorous
and I reduce 12.5 gallons to 10-10.5 gallons in a typical batch,
and that is slightly covered. I don't see how you can get a good
boil and only lose 10% unless you are returning a lot of the vapor
to the pot. If this is what you are doing, it seems to me that
the thermal loading is the same as letting it evaporate and either
starting with more water or topping up after the boil.
On a related note: I think that all this concern over
covering the boil is BS. DMS is incredibly volatile. Unless you're
using a pressure cooker I don't see how you could keep it in if
you wanted to. I used to just crack the lid on my boils when I
used an electric stove and I didn't have excess DMS (IMO). I
recently did the experiment suggested here a few years ago and
collected the condensate from my lid during the boil and tasted it.
Water.
- --
Jeremy Bergsman
jeremybb@stanford.edu
http://www-leland.stanford.edu/~jeremybb
------------------------------
Date: Thu, 7 May 98 10:32:08 -0700
From: brian_dixon@om.cv.hp.com
Subject: Re: Re-started fermentation in the secondary
Arnold asks about apparent restarting of the fermentation after
racking to a secondary, and I believe, adding dry hops.
Observations that I've made in the past from normal and from one
particular infected fermentation have lead me to believe the following
conclusions about increased airlock burbling after racking:
- Dissolved CO2, and CO2 trapped or 'stuck' to suspended yeast can be
released during the racking process. The result is increased bubbling
of the airlock and yeast falling out of suspension. This is normal
and can be ignored unless the bubbling lasts a long time.
- Primary fermentations that are not complete, but happen to have a
leaky fit around the stopper and airlock (or bucket lid) often appear
to be done or slowing, but then increase after racking. What really
happened was that after racking the leaks in the system were fewer or
gone and the CO2 is now going through just the airlock. Knowing how
long the beer's been in the primary is your primary clue here, plus
any SG measurements you may have taken.
- Infections (yikes!) are usually indicated when the increased
bubbling in the secondary _continue_ longer than expected. For
example, if you know enough time has passed to make you sure the
primary is complete (longer than about 4-5 days), and if the increased
bubbling in the secondary has not slowed within a few hours, then it's
possible that you have an infection. If the bubbling rate continues
to increase, and then lasts for a long time (a few days or sometimes
longer), then an infection may also be present. To understand what is
happening, consider the fact that the 'good' yeast that we conduct our
fermentation with is fairly constrained in what it can metabolize as
compared to wild yeasts or bacterias that are present in nature (only
some of which will produce a gas during metabolism). Wild or mutated
yeasts in particular can digest more complex sugars and starches than
beer yeasts. When an appropriate bacterial or wild yeast infection,
or a mutated beer yeast exists in your wort (shit happens), then the
'fermentation' can continue long after a normal fermentation would
finish because a longer more complex list of 'food' is being digested
out of your wort. Other symptoms that provide clues here are taste,
mouth feel, and appearance. Obviously everyone knows about the rings
and things that are visible indicators of infections, but what about
loss of head forming capacity? If your beer has the ability to form a
nice head of foam on bottling day, but has no capability to do the
same a couple of weeks later, and you saw some kind of extended
fermentation going on, then it is likely that you had an infection
that was capable of digesting medium and high molecular weight
proteins (and probably starches). The beer will often taste/feel
thinner after it's been in the bottles for awhile, and there will
often be off-flavors present (sourness, 'stale'ness, 'odd somethings'
etc). And sometimes, these off flavors change or go away somewhat
over time. Wild yeast infections tend to peak in sourness at around 8
weeks in the bottles, then it diminishes a bit but doesn't go away
completely. Don't ask me how I learned about all this, but a certain
experience with plastic fermenters and one particular Dusseldorf style
Altbier might be good hints to start with...
Good luck, and I hope you don't have an infection! I gave up on my
equipment after some thorough sanitizing efforts and a couple more
brews failed to help. I switched to all glass fermenters and bottle
out of a carboy with a simple siphon system, e.g. no plastic bottling
bucket. And I have no issues with replacing hoses, racking canes, and
bottling wands on a regular basis! Since that change, I have had no
further problems with infections.
Brian
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End of HOMEBREW Digest #2708, 05/08/98
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