Copy Link
Add to Bookmark
Report
HOMEBREW Digest #2806
HOMEBREW Digest #2806 Mon 24 August 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:
Diluting OG (Mark Riley)
Thank you (Bruce Daniels)
Salt solubility in beer (Fred Johnson)
Mort's Magnificent Seven (Charley Burns)
The truth about American Beers ("Robert C. Sprecher, M.D.")
Stats ("Dr. Pivo")
using our yeastie friends (Mark Tumarkin)
post stats ("Dr. Pivo")
Topping off formula ("Steve")
dunking pretzels (as salt adjunct) ("Dr. Pivo")
Filter ratings for air injection into wort (Dean Fikar)
need help with wild irish rogue clone (Jonathan Edwards)
Topping water and OG (bob farrell)
RE: Keg Pressure (LaBorde, Ronald)
DC area recommendations? (Paul Kensler)
burning mold onto a bottle (Mike Allred)
Re: Even More Yeast .. ("Steve Alexander")
Upgrading to all-grain brewing (DGofus)
Chimay beers (dgofus@aol.com) (DGofus)
Gravity Adjustment ("C Perilloux")
Hot Side Aeration ("George De Piro")
First Brew (Timothy Skowronek)
refractometers (DR McKeel)
statistical significance (James_E_Pearce)
Also Sprach Zarathustra (Jim Liddil)
Homegrown hop plugs (MrMike656)
Let a good beer be the exclamation point at the end of your day as
every sentence deserves proper punctuation...
NOTE NEW HOMEBREW ADDRESS: hbd.org
Send articles for __publication_only__ to post@hbd.org
(Articles are published in the order they are received.)
If your e-mail account is being deleted, please unsubscribe first!!
To SUBSCRIBE or UNSUBSCRIBE send an e-mail message with the word
"subscribe" or "unsubscribe" to request@hbd.org.
**SUBSCRIBE AND UNSUBSCRIBE REQUESTS MUST BE SENT FROM THE E-MAIL
**ACCOUNT YOU WISH TO HAVE SUBSCRIBED OR UNSUBSCRIBED!!!
IF YOU HAVE SPAM-PROOFED your e-mail address, the autoresponder and
the SUBSCRIBE/UNSUBSCRIBE commands will fail!
For "Cat's Meow" information, send mail to brewery@hbd.org
Homebrew Digest Information on the Web: http://hbd.org
Requests for back issues will be ignored. Back issues are available via:
Anonymous ftp from...
ftp://hbd.org/pub/hbd/digests
ftp://ftp.stanford.edu/pub/clubs/homebrew/beer
AFS users can find it under...
/afs/ir.stanford.edu/ftp/pub/clubs/homebrew/beer
JANITORS on duty: Pat Babcock and Karl Lutzen (janitor@hbd.org)
----------------------------------------------------------------------
Date: Fri, 21 Aug 1998 23:31:36 -0700
From: Mark Riley <mriley@netcom.com>
Subject: Diluting OG
AJ writes:
>Bruce Daniels asked for a simple method for gravity adjustment. Let's
>illustrate with an example. You have 4 gallons of wort at1.052 and you
>want 1.048.
A quick and dirty way to get to the desired volume is to multiply the
current volume by the current gravity units and divide by the desired
gravity units:
4 gal * 52 / 48 = 4.33 gal
So, you'd add 1/3 gal to hit your desired OG.
Cheers,
Mark Riley
http://hbd.org/recipator
------------------------------
Date: Sat, 22 Aug 1998 07:41:18 -0400
From: Bruce Daniels <bdaniels@Hamptons.Com>
Subject: Thank you
Just a Thank You to all who have E-mailed me responses on my last couple
of questions. They were a hugh help!
Bruce Daniels
------------------------------
Date: Sat, 22 Aug 1998 09:18:24 -0400
From: Fred Johnson <FLJohnson@worldnet.att.net>
Subject: Salt solubility in beer
AJ measured conductivity of alcohol/water solutions and was able to
produce a standard curve with the hopes of applying it to beer. But he was
less sucessful in getting reasonable values of alcohol content on real
beer. He posted:
> The aliquot was
> diluted to a liter and the conductivity of the dilution measured. ABV
> vs. conductivity is fit quite well by a straight line (r = 0.992) which
> means that we can use this technique pretty effectively for finding the
> amount of alcohol dissolved in water. When it came to beer, however,
> things didn't work out so well. I measured a lager with an ABV of 5.95%
> using exactly the same technique as for the calibration samples. The
> estimate for ABV using the calibration regression was 10.5%.
>
I see at least a couple of problems here.:
1. Beer has LOTS of conductingions in it compared to your pure
alcohol/water solutions. Your baseline value has to be much greater than
pure alcohol/water solutions. Did you correct for the conductivity of the
beer before you added any salt?
2. EtOH/water solutions are probably different than denatured
alcohol/water solutions in their ability to dissolve NaCl.
3. Many other things in beer probably affect NaCl solubility, in which
case you would have to have a standard curve for every beer you make and
you would have to assume that the only thing different between different
batches is the ethanol content-- an unreasonable assumption.
Anyone out there have a different opinion?
- --
Fred L. Johnson
Apex, North Carolina
------------------------------
Date: Thu, 20 Aug 98 11:16 PDT
From: caburns@egusd.k12.ca.us (Charley Burns)
Subject: Mort's Magnificent Seven
Man did my brain sweat over this one. Scientific Notation and Metric systems
tossed together with Degrees Plato is NOT my strong suit. But nevertheless,
here's my attempt to use Mort's Magnificent Seven.
Optimum pitching rate assumption: 1,000,000 cells per milliliter (ml) of 1
degree Plato of wort.
1,000 ml = 1 litre
5 gallons = 19 litres
therefore
19,000 ml = 1 each 5 gallon batch
In case you haven't figured it out yet, this is the long slow way to get
around to final conclusion. Those of you good in this sort of math, can hit
page down and go to the next post now.
1 batch of 1 degree plato wort therefore needs 19,000,000,000 (billion) cells.
Assumption 2: 1 degree plato = .004 points of specific gravity (please
correct me if I'm wrong here - its memory fading quickly).
So, 1 batch of 1.004 (SG) wort needs 19,000,000,000 (billion) cells of yeast.
1 batch of 1.052 Pale Ale wort needs 247,000,000,000 (billion) cells of yeast!
We're getting closer now.
The worst case (least dense) sample out of Mort's Magnificent Seven (See
hbd#2802) provided 2.0e+9 cells per gram of yeast cake. This converts to a
"normal" number of 2,000,000,000. I know, you guys that are mathematically
inclinded think I'm nuts for keeping all the zeros around. Well, now that
I'm getting used to it, it does seem like a lot of typing for nothing, but...
ok, so now we divide cells needed by cells per gram to get total grams needed:
247/2 = 123.5 grams.
Mort was kind enough to provide the divisor in his follow up post to convert
this semi liquid yeast cake in grams to fluid ounces: 29.5727.
so, 123.5 / 29.5727 = 4.176 ounces (of yeast slurry for 5 gallon batch).
2 primary caveats:
Assumes 2,000,000,000 (2.0e+9) cells per gm of yeast slurry (low density)
Assumes 93 percent viability (very high).
Assuming a 50% viability, we'd need to pitch 8.34 oz of slurry.
Assuming a 25% viability, we'd need to pitch about a pint of slurry.
My last 5 gallon batch of brown ale (sg 1.053) I pitched with about a pint
of 1056 slurry (which had been in the fridge under distilled water for a
couple of months). It took a good 18 hours to get action, even at 72F (ambient).
Prior to that I pitched a 2 quart starter from a smakpack of 2206 into a
1.075 Bocktoberfest (layer of yeast only about 1/8" thick at bottom of
starter). It took off with a krausen within 2 hours - but took 25-26 days to
ferment out.
So, I think both quantity of yeast PLUS state (ie active or dormant) makes a
huge difference in visible lag time and the total ferment time. More active
yeast makes shorter lag time, but not necessarily a shorter ferment time.
The brown finished at 1.010 in 4 days (quick total time, but long lag time).
Any comments from the collective. I need to go rest my brain now.
Charley (measuring ounces but not counting cells any more) in N. Cal
------------------------------
Date: Sat, 22 Aug 1998 10:34:37 -0400
From: "Robert C. Sprecher, M.D." <rcs8@en.com>
Subject: The truth about American Beers
Actual quote from a patient's medical chart:
"The catheter was draining urine the color of American beer"
'nuf said.
- --
Robert C. Sprecher, M.D.
Pediatric Otolaryngology
Rainbow Babies and Childrens Hospital
Case Western Reserve University
Cleveland, Ohio
------------------------------
Date: Sat, 22 Aug 1998 16:36:19 +0100
From: "Dr. Pivo" <irv@wireworks.se>
Subject: Stats
Statistics are tricky things. Beautiful in their cleanliness. Ugly in
the way they can be manipulated or missinterpreted.
I believe Mark Twain wrote something like "There are three kinds of
lies: white, innocent lies, black insidious lies, and then there are
STATISTICS!"
Just saw this and thought it should be cleared up:
Jim Liddil wrote:
> Dr Pivo wrote:
>
> >The good news is that there is "almost" a statistical significant
>
> Sorry but there is no almost about stat. sig. Either it is or it is not.
> You perform a t-test (provided you have enough data points) and at a p-value
> < 0.05 either it is or it is not. It's like sterile.
Nope. It's like "sanitised". One generally chooses an arbitrary
"confidence" level to say "OK, looks pretty good". 95% is pretty common.
1% is better.
Neither of these is "the truth" (as in sterility, which is a pre-defined
term suggesting an absolute condition).
OK. I'll do one of my "everyday science" things (and try and spell
potatoe correctly), and let a statistician jump in and correct any
missinterpretations.
When you are comparing stuff that can only have two possible outcomes
(like "heads and tails" on a coin), and you want to figure out if the
coin is "weighted", so one side turns up more often, there's a pretty
good way to test that (flip it over and over and over again, and write
down your results).
When you statistically test your results, you are simply saying "what
are the "odds" that any difference that has occurred, happened because
it is "true", or looking at the .O5 or .01 number, what are the "odds"
that there is no real difference, and this occured by chance.
It's not truth, Jim. At a .05 level, with your definition, you are
proving that it is impossible to be dealt "four of a kind".
It won't happen 5 times out of a hundred, but it will happen (just never
to me, darn it.)
If I was going to express myself correctly in "scienterrificese", I
should have said.
" testing showed a difference with a confidence level of 85%"
In other words, If you were just "flipping a coin" (and there was no
real difference), you would have gotten that result about 15% of the
time, and that is generally not a level that we feel terribly
"confident" about (sorry to mix terms... I did think it was cute).
To repeat my statement in more accepted terms of the lithurgy.
"Testing between cooled and non cooled batches showed a statistical
significance of 0.15. This seems to indicate a need for more clearly
restricting the variables and confounders mentioned (I haven't jumped on
P O2 at fermentations inception, loss of hop aromatics, etc. here, but
in a "big guy" paper those should be pointed out), and repeating with a
larger sample size, to more clearly illuminate the existance of possible
perceivable taste effects induced by rapid versus slow cooling."
Now isn't that bloody boring to hear? Hardly even had any commas,
hyphens, bunch of dots in a row, or any other fun stuff!
Think I'll stick to "almost significant". I think most folks understand
that, and if people are already confusing a .05 level of significance
with an absolute condition (THE TRUTH), it's well worth avoiding those
terms.
Dr. Pivo
------------------------------
Date: Sat, 22 Aug 1998 10:46:22 -0400
From: Mark Tumarkin <mark_t@ix.netcom.com>
Subject: using our yeastie friends
Jim:
Thanks for the great post "Even More Yeast" in HBD 2805. You pointed out
some things that really set my mental yeasties to fermenting. Let me
preface this by saying that I am severely math and science challanged. I
enjoy trying to understand some of the posts by AJ, Steve, and some of
our more scientific posters, but a lot of it goes way over my head and
understanding. If brewing can be approached as an art or a science
(preferably an inspired combo of the two), I am clearly on the art end
of the spectrum. I suspect this also describes a lot of other HBD'rs.
However, it is clear to me as an artist or craftsman that the more I can
understand about using my tools (including the science side), the better
art (beer) I can produce. So I rarely make use of the page down key,
rather I try to pick up a piece of the puzzle or two out of posts that
generally go over my head. The bottom line being that I want to learn as
much as possible about "best practices" and apply that as best I can to
my particular brewing system and practices.
You said in your post -
"The other day I posted a bunch of numbers from books. Now this is all
fine
and good and such. But for me I would prefer to do things a little
differently for the beer I make and my view of the world. When I make
wort
I would prefer to use it to make beer ratter than grow yeast. I prefer
to
grow the majority of my yeast separately. When yeast is put into wort it
can either ferment and make ethanol or it can grow and make more yeast.
Certainly both occur at the same time but one or the other can be favor
given certain conditions. In this discussion I am talking about a normal
brewery fermentation with a 12 Plato wort and yeast cells that are 95+%
viable by methylene blue staining.
One can choose to pitch any amount one chooses. Also one can choose to
oxygenate the beer at a given level to effect the amount of yeast
growth."
This really caught my attention and made me think about the yeast and
starters in a different light. Much as I love our yeastie buddies, I
would much rather make beer than grow yeast. Obviously, we have to do
both, and "brewers make wort, yeast make beer." Anyway, I'd like to ask
you to clarify or expand some of your points - keeping the practical
applications in mind.
"Now let's consider the two situations we as brewers deal with (1) is
yeast
that comes from propagation under highly aerobic and nutritionally
adequate
conditions and (2) re pitching yeast that has been previously used to
ferment a beer."
You discuss doing starters using stir plates or shakers, I'd love to try
that but don't have the equipment (probably most of us don't). I'm
really more curious about #2. I quess most the stepped-up starters I do
fall into this catagory. And if I understand your post, these would have
insufficient oxygen and consequently low lipid levels. I had posted
before about pitching onto the yeast cake from a previous batch. This
has worked well for me. I oxygenate by putting the carboy in a plastic
milk crate, tipping it on one edge, and rocking vigorously. I have an
oxygen tank and air stone on my wish list, but haven't bought them yet.
Do you think this procedure is adequate, or how can I improve it? With
the ultimate aim of making better beer, what would be the "best
practice" for oxygenating the wort in this situation?
"So this is what I am trying to do in my own brewing practice. If you
prefer to grow yeast, that is fine with me. If you don't worry about
off
flavors or slow fermentations then by all means you can ignore all of
this.
And of course I am sure there are plenty of people out there who end up
with great beer using little to no starter. This merely some
ramblings."
I do worry about off flavors and slow fermentations, so if you could
"ramble" a bit more about how we can apply these ideas I'd be really
interested.
TIA,
Mark Tumarkin
Gainesville, FL
------------------------------
Date: Sat, 22 Aug 1998 17:25:43 +0100
From: "Dr. Pivo" <irv@wireworks.se>
Subject: post stats
While I am on the subject of Jim Liddil, since I post here so seldom, I
might mention that I was very impressed with the information he gleaned
from the Big Boy Brewing School (I gathered it was some such, I
honestly don't know what a "Seible" is... guess we pray to different
gods.), but mostly impressed by how he was able to sift through that
information to find what might be relevant to a home brewer.
Showed an unusual sense of perspective, and his conclusions, though
"couched" in quite polite terms, were very refreshing thought I.
"How convenient", I thought, as he mentioned (among other choice
tidbits) that even the Big American Breweries put HSA way down on their
list of oxidative worries (Remember this is the same industry whose
collective motto is: "Guaranteed to not leave a taste memory"), after I
felt I've been shouting that down a long dark tunnel for a couple of
years, and at the very moment of reading it was sitting over a cellar
filled with my attempts to finally find out at what threshold this
boogie-man actually appears.
Thanks, Jim
Dr. Pivo
------------------------------
Date: Sat, 22 Aug 1998 11:26:19 -0400
From: "Steve" <stjones1@worldnet.att.net>
Subject: Topping off formula
Bruce asked about a formula for adjusting SG.
While AJ's answer is no doubt very precise, I
think this is much simpler and accurate enough for
most brewers.
Take the starting gravity (drop the 1 dot) and
multiply times the original volume to get total
'gravity points'. Divide this by the desired
gravity (again, drop the 1 dot) and subtract the
original volume from this result. Finally,
multiply by 4 to find the number of quarts of
topping water to add.
Using AJ's example:
You have 4 gallons at 1.052 and you want 1.048.
4 gal * 52 pts/gal = 208 pts
208 pts / 48 pts/gal = 4.33 gal
4.33gal - 4 gal = .33 gal
.33 gal * 4 qts/gal = 1.32 qts.
While 1.32 qts isn't exactly 1.32 liters, it is
close enough for me.
Hoppy Brewing!
Steve
State of Franklin Homebrewers
http://home.att.net/~stjones1
------------------------------
Date: Sat, 22 Aug 1998 17:37:51 +0100
From: "Dr. Pivo" <irv@wireworks.se>
Subject: dunking pretzels (as salt adjunct)
Please excuse it if this idea has already come up, usually scim AJ
deLange's stuff, and haven't followed the whole thread.
He was suggesting NaCl's high solubility in water and low in alcohol, as
a possible "quicky" way of measuring alc content.
Wouldn't electro-resistivity, as a function of dissolved ions, pre and
post dumping the salt in, be a way to pluck that number out (should be
irrespective of sample size or ammount of "dumped salt", once over
saturation)
Sorry if this thought has already been posted--- just having mind
wanderings.
Dr.Pivo
------------------------------
Date: Sat, 22 Aug 1998 11:19:38 -0500
From: Dean Fikar <dfikar@flash.net>
Subject: Filter ratings for air injection into wort
I've recently acquired an aquarium pump and SS airstone for continuously
aerating my yeast starters. I was in the process of locating an air
filter when I came across a one micron filter that would be easy to
splice between the pump and the wort. The device is designed to filter
CO2 which is injected directly into human arteries ("CO2 angiography").
Is a one micron rating good enough? Seems like I've read that the
filters specifically designed for brewing purposes are in the submicron
range. I would think that if it's good enough for filtering gases into
the human body then it should be okay for filtering room air going into
a yeast starter. Any thoughts?
------------------------------
Date: Sat, 22 Aug 1998 14:37:38 -0400
From: Jonathan Edwards <jdedward@us.ibm.com>
Subject: need help with wild irish rogue clone
hey now,
i'm getting ready to do a wild irish rogue oatmeal stout clone. it's one of the
best oatmeal stouts i've had even if it isn't true to "aha style". here's my
recipe for 6 gallons all grain assuming 70% efficiency:
6lb Western 2-row
6lb Klages 2-row
1lb Crystal 135L
.75lb Roasted barley
.50lb Chocolate
1.5lbs flaked oats
3.75oz Cascade 5.7% 60 minute whole leaf
1.0oz Cascade 5.7% 5 minute
pacman yeast cultured from bottle
og 1.066
ibu 59
according to rogue's web page, i think this is pretty close. not sure about
the dark malts. any ideas on those? i'm never sure what to use in my oatmeal
stouts. i don't want an excessive roasted burnt taste.
thanks,
jonathan
------------------------------
Date: Sat, 22 Aug 1998 11:57:57 -0700
From: bob farrell <bfarrell@windermere.com>
Subject: Topping water and OG
Bruce Daniels requested a rough formula for topping off wort in the primary
to get the desired OG.
I suggest:
Example- OG 1050 with 4 1/2 gallons = 50 x 4.5 = 225 gravity units.
If the target gravity is 1045, simply divide
225 by 45 = 5 gallons total. Just add 1/2 gallon.
Bob Farrell
Portland, OR
------------------------------
Date: Sat, 22 Aug 1998 14:03:18 -0500
From: rlabor@lsumc.edu (LaBorde, Ronald)
Subject: RE: Keg Pressure
From: "Wilson, Todd (MCI)" <Todd.W.Wilson@mci.com>
>I have 3 kegs hanging off of a 3 way manifold in my fridge. If the
pressure
>on my co2 is set to 15psi am I getting 15psi to each keg or am I getting
>5psi to each keg?
15
Ron
Ronald La Borde - Metairie, Louisiana - rlabor@lsumc.edu
------------------------------
Date: Sat, 22 Aug 1998 23:20:47 GMT
From: paul.kensler@ibm.net (Paul Kensler)
Subject: DC area recommendations?
I will be travelling to the Washington DC (Northern VA) area soon,
and need some recommendations on "can't miss" local breweries or
brewpubs, and recommendations on what locally available beers I should
try.
Please respond by email - paul.kensler@ibm.net
Thanks!
Paul Kensler
Just finished brewing a stout, in Plano, TX.
------------------------------
Date: Sat, 22 Aug 1998 21:34:05 -0600
From: Mike Allred <mballred@xmission.com>
Subject: burning mold onto a bottle
John A. MacLaughlin said
>Rod and Mike Allred also comment on baking bottles to remove mold.
>A strong chlorine bleach solution (one ounce per gallon) will cause
>mold to separate from a smooth glass surface in a day or two (or
>maybe three to five). Then you can just pour it down the drain,
>after shaking vigorously to get it through the bottle's neck.
....Then bake them.
I did not say to bake bottles to remove mold. This would make a stinking
mess. I clean them first (like John's method), then I bake them. I don't
know if mold spores can live after the chlorine soak, but I sleep better at
night...anyway I know almost everyone in hbd disagrees with us bottle
bakers, but the point of my original post was to say that 'IF you are going
to bake, make sure that the bottles are clean first'.
------------------------------
Date: Sun, 23 Aug 1998 06:57:34 -0400
From: "Steve Alexander" <steve-alexander@worldnet.att.net>
Subject: Re: Even More Yeast ..
Jim Liddil writes ...
>Steve Alexander wrote:
>>For example it's been stated that 3X is
>>the yeast growth rate in ale breweries; perhaps this is so ( I still have
>>doubts) , but was the purpose to perform quicker fermentations, or to
>>avoid yeast growth byproducts ? If the latter why aren't they pitching a
>>full
>>complement of yeast and shooting for near zero growth (because it would
>>cause zero fermentation right ;^) ) ?
>Let me start with this:
>
>"In sharp contrast to the long-held belief in brewing that the bulk of wort
>attenuation is done by nongrowing cells, it is now clear that the specific
...
>"The rate of fermentation will depend on the rate and extent of yeast growth"
>Remember this? :-)
Yeast biomass growth is one major energetic requirement for yeast. I not only
have stated this recently (Jim chooses to quote selectively here) but have also
posted the constants associated with the energetics required some time ago.
That there is a relationship between growth, energy required and fermentation
rate - there is no doubt. Without context (as I said before) it is impossible
to impute much meaning to the "principle" stated. What is clear is that under
stationary conditions, the rate of fermentation is directly related to the
yeast biomass in a proportional fashion. The Seibel statement as quoted (and
I have pointed this out before too) does not define the "depend"ency in any
way.
The reason that Jim cites - that much energy goes into growth - *may* be the
reason Seibel intended, but it still doesn't define a clear relation since
yeast, even without growth do require energy (so ferment) for reasons such as
creation of storage carbohydrates and some lipids (yes - even without O2 and
growth). This is something like the difference between stating that the GDP
depends on the total goods produced (a definition) and stating that the GDP
depends on the work ethic of the populous (possible, tenable, but without
detail almost meaningless).
Jim states ...
> When yeast is put into wort it
>can either ferment and make ethanol or it can grow and make more yeast.
>Certainly both occur at the same time but one or the other can be favor
>given certain conditions.
NO - There is a fundamental error in thinking on Jim's part here. Yeast don't
*either* grow or ferment - it isn't one or the other - it's one(ferment) or
both. They ferment in order to have energy in order to carry out all sorts of
biological activity. If possible they reproduce, if not they still can build
saturated fats, storage carbohydrates, trehalose and glycogen, and also require
energy for normal biological functioning. It takes considerable energy just to
keep the internal salt ion gradients in balance. This error I think taints the
remainder of Jims post - it needs a revision because it does contain some
important ideas.
[ description of pitching high and low sterol yeast omitted ...]
>So this is what I am trying to do in my own brewing practice. If you
>prefer to grow yeast, that is fine with me. If you don't worry about off
>flavors or slow fermentations then by all means you can ignore all of this.
Frankly, despite the misunderstanding about yeast energetics I think that Jim
is saying something very important here. So important that I asked the
questions myself on HBD a few weeks back.
What is the desired state of yeast at pitching with respect to O2 dependent
lipids and storage carbohydrates ? What are the reasons for choosing higher
versus lower growth factors ? For example do the byproducts really have
substantially lower contributions when the new crop is 66% (3X growth) versus
83%(6X growth) ? What are the flavor consequences of higher versus lower
pitching rates - and so what rate is optimal for flavor.?
Jim says that he prefers to *not* have yeast growth - but one of his reasons
(fast fermentation) defies his own quote about 33X slower attenuation. The
off-flavors issue I find much more believable, but still there are reports in
the lit of poor flavor under conditions of extremely high pitching levels too.
I think that the 1% versus .125% sterol levels are perhaps taken too literally
as limits and I suspect that there is considerably more variation in practice
than this but I do think that lipid and particularly sterol levels may be a
factor in poor fermentation such as the BT article Jim cites with 2 qt starter
into 26 qt of 16.5P wort and resulting stuck fermentation.
I think that balancing the O2 dependent lipids in and available to yeast is a
factor worthy of consideration and the sort of control that Jim suggests. I
just don't think that all the i's are dotted and t's crossed in methodology
yet. Without understanding the "off flavors" created by underpitching and
growth in detail we never will get to the bottom of this.
I'm not sure if this was in a previous post of a private comm, but one term in
models for fusel production is yeast growth rate related *but* the coefficient
on the term is also dependent on the specific related amino acid - so that at
higher amino acid levels the fusel production is also moderated (and from some
research even stops). If this fusel term is the issue for reducing yeast
growth in order to prevent off flavors (and I'm not sure this is the only
factor) then adding a bit of valine, leucine and isoleucine amino acids to the
wort might be a preferable solution to inducing slow fermentation and low
growth - at least on HB scale operations. I'm not stating that this is the
case - just stating that without understanding the nature of the problem that
rushing to solutions is premature.
Steve Alexander
------------------------------
Date: Sun, 23 Aug 1998 08:24:34 EDT
From: DGofus@aol.com
Subject: Upgrading to all-grain brewing
I need the collectives help. I am interested in going all-grain brewing but I
need some help. I am happy as an extract/partial mash brewer, but think that i
can do better! What equipment do I need, or would you reccomend? here is a
list that i came up with from my readings.
1. Mash tun
2 lauter tun
3. ability to boil a full 5 gall. batch
Any help would be greatly appreciated. Private e-mail ok
Bob Fesmire
Madman Brewery (soon to get Madder)
Pottstown, PA
Dgofus@aol.com
------------------------------
Date: Sun, 23 Aug 1998 08:32:49 EDT
From: DGofus@aol.com
Subject: Chimay beers (dgofus@aol.com)
I recently purchased a case of Chimay Grand Reserve (blue). Can anybody fill
me in on this brew and the other offerings from this brewery. The beer is
great...one problem, the first beer that I opened gave an extreme amount of
head to the beer. It took a long time to get the head down enough to continue
to pour the beer. It seemed like an " infected " beer. My friend, who I bought
a case for, also said the same thing about his first beer. He now says that
after two more bottles, everything is fine. Did I over handle or shake the
beer too much during the ride home, or pouring? What is going on. I have not
yet tried another bottle. At $75 a case, I am trying to preserve them!
Bob Fesmire
Madman Brewery
Pottstown, PA
Dgofus@aol.com
------------------------------
Date: Sun, 23 Aug 1998 23:18:47 +1000
From: "C Perilloux" <peril@bigpond.com>
Subject: Gravity Adjustment
>Bruce Daniels asked for a simple method for gravity adjustment. Let's
>illustrate with an example. You have 4 gallons of wort at1.052 and you
>want 1.048.
>...Subtract 1 from the specific gravity, multiply by 1000 and divide by 4.
>(1.052 -1)/1000/4 = 13P. This means that 100 grams of your wort... etc.
>...(1000/1.052) = 950.57. Thus 0.9507L of wort contains... etc
>...10 times the Plato value by the SG: 120*1.048 = 125.76 grams... etc.
>...need a total of 2067.81/125.76 = 16.44 liters to hit a gravity of...
>... etc.
>...You had 15.12L so you should add 1.32 liters more.
My God, AJ!! I have to give it to you, it's detailed and accurate,
but when the poor guy sitting there at the end of long brew session
is confronted with all the arithmetic, he must think there's an easier
way, even at the price of some accuracy.
If the current and desired SG's are relatively close (i.e. don't do
this to dilute 1.100 down to 1.040!), here's a quick and dirty:
Current SG 1.052 for 4 gallons
Desired SG 1.048
x = (52/48 - 1) *4 gal
x = 0.33 gal
This comes out to 1.26 liters. Close enough, considering that
most fermenters aren't marked precisely enough to worry about
0.06 liters worth of error, not to mention that the SG reading you
make with a typical homebrew hydrometer is only within a point
or two anyway.
Calvin Perilloux
Turrella, Australia
------------------------------
Date: Sun, 23 Aug 98 11:13:38 PDT
From: "George De Piro" <gdepiro@fcc.net>
Subject: Hot Side Aeration
Hi all,
Dr. Pivo did a nice little experiment to demonstrate that HSA is not the
big deal
some people believe it is. He also instructs me to pose in a silly
manner. Most
illogical.
Anyway, I believe Rob Gump and I wrote in one of our "live from Siebel"
posts
that we learned HSA isn't the horrific monster some believe. It is
damaging to
beer, but not nearly as damaging as some of the other things we do to it.
The
"short George list of common beer destroyers" is something like (from
worst to least
worst):
1. Shoddy sanitation practices. No need to expound on this.
2. Underpitching and other abuse of yeast. This causes such a broad
array of
problems that it is truly staggering. I have said much about this, and
will say more,
mark my words...
3. Aeration of the fermented beer: incredibly damaging, even to
homebrewers.
An easy experiment: aerate one bottle of beer, cap it, wait a few days.
Taste it
blind against a bottle from the same batch that is unabused. You need
not waste
precious homebrew on this.
4. Cloudy lauter runoff. Don't skimp on the time it takes to achieve
clear runoff!
5. Hot side aeration. The damage this can cause may be more subtle than
Dr. Pivo
was hoping to find, especially during the beer's youth. One thing that
can happen is
the lack of maltiness. The beer won't taste off, but it will be flat in
its malt character.
I agree with Dr. Pivo that with the myriad other things small brewers can
do to their
beer HSA is near the bottom of things to take care of. That doesn't mean
you
should go out of your way to aerate the hot wort, though! Just don't
take the
elimination of HSA too far (working with SCUBA gear in a nitrogen
atmosphere, etc.).
There are better places to spend your energy.
Another caveat about experiments like Dr. Pivo has presented: who were
the tasters?
Are they trained tasters? What about the amount of HSA in the control
batch? Maybe
there is some HSA going on in both beers?
I'm not trying to belittle what Dr. Pivo did (in fact, I think it's
*great*), but keep this stuff
in mind when reading anybody's work.
Have fun!
George de Piro (Nyack, NY; just home from 3 days of eating Herrell's ice
cream.
If you don't know it, you don't know what greatness is.)
------------------------------
Date: Sun, 23 Aug 1998 12:10:09 -0500
From: Timothy Skowronek <cosmo@indy.net>
Subject: First Brew
I just compleated my first batch of beer, using a recipe for an
Oktoberfest form Papazian, slightly modified for my conditions. It's
not what I expected and would like some feedback. The recipe:
6.6 # Irez Amber extract
!# amber dry
1/2 # carmel malt
!/8 # roasted barley
1/.8# toasted barley
3 oz fresh Hallertauer (boiling)
1/2 oz plug Saaz (flavor)
1/2 pellet Saaz (aroma)
I brewed on 8/1, steeping the grain and adding 2 gal wort to 3 cold
water, pitch the yeast (Wyeast british Ale II, because I have no
basement and could not keep the batch below 65 F) . I started the yeast
a day or two earlier before pitching. The temp was kept at 68 F the
whole time and my OG was 1.044.On the morning of 8/4, I transfered to a
carboy and the SG was 1.026. after two days, the SG never dropped below
1.022. Was it stuck? I thought the combo of cold water and some
shaking of the wort after adding to the cold water would give it enought
O2. I waited till 8/10 and bottled. It is now 8/23 and I just popped
one. It is like drinking malt extract. I exaggerate a bit - it seems
similar in initial flaver to Sam Adams Double Bock, but really cloying
in the aftertase. I think that the fermentation stopped too early.
Does anyone know why this happened? Is it possible to salvage it even
after I bottled? I'm just happy that the things I was most worried about
(sanitation, infection, no caronation) posed no problem at all. Any
help or suggestions would be appreiated.
Thanx,
Cosmo
------------------------------
Date: Sun, 23 Aug 1998 20:12:39 -0400
From: DR McKeel <drmckeel@twave.net>
Subject: refractometers
Greetings fellow brewers,
Recently I had considered the puchase of a refractometer. However, when
I began looking into doing so I found that the price and features can
vary cosiderably. Among the different features was automatic temperature
compensation and various scales. If any of you that have any experience
with refractometers would be willing to share your thoughts with me in
order to help me to make an educated selection, I would greatly
appreciate it.
Dwayne (I've never met a beer that I didn't want to brew) McKeel
drmckeel@twave.net
Musty Olde Cellar Homebrewery
------------------------------
Date: Mon, 24 Aug 1998 11:04:46 +1000
From: James_E_Pearce@nag.national.com.au
Subject: statistical significance
From: James E Pearce@NAG on 24/08/98 11:04 AM
Jim Liddel writes:
>Sorry but there is no almost about stat. sig. Either it is or it is not.
>You perform a t-test (provided you have enough data points) and at a
p-value
>< 0.05 either it is or it is not. It's like sterile. Oh and I like to
>send my bottles out for gamma irradiation so they are sterile and I don't
>have to worry about heating up the house with the pressure cooker or oven.
Sorry, but I'm with Dr Pivo here. There is no good reason to choose a
p-value of 0.05 over 0.051 (for example); indeed, if there are a reasonable
number of data points there is no 'statistically significant' difference
between the T values that give p-values 0.05 and 0.051. Dr Pivo said that
he needed more data points to chekc this out, that is exactly right.
A p-value of 0.05 means that you are concluding there is a difference when
there is none 1 time in 20.
Cheers
James in Melbourne
------------------------------
Date: Sun, 23 Aug 1998 18:52:21 -0700
From: Jim Liddil <jliddil@azcc.arizona.edu>
Subject: Also Sprach Zarathustra
This simple my take on the BT vol 6 no1 article.
It has been my experience and that of others that one can get about 2 X
10e8 cells /ml in a starter using a stir plate etc. This seems to be a
maximum and typically I get about 1 X e-8 for the ~1045 starters I have
tested lately. Let's look at the BT article in vol 6 no.1 that compared
decoction and RIMS beers and experienced a stuck fermentation with the 16.5
P bock. The text indicates that the wort was pitched with a 2 quart
starter. 2 quarts is equal to 1.89 liters. All the text says is that the
starter was made using a step up procedure and does not indicate if the
starter was continuously agitated or not. It is then likely the yeast had
a low sterol and UFA level when the went into this high sugar environment.
I am going to make the leap of faith and guess the starter had 1 Xe8
cells/ml at the time it was pitched into the beer. Simple math indicates
that the starter would have had 1.89e11 cells total (1.89 Liters X 1e8
cells/ml). This was pitched into a volume of 6.5 gallons. the total
volume then is 6.5 gallons (24.6 L) + 1.89 L = 26.49 L. If we do the math
again this gives us a figure of 7 X10e6 cells/ml in the wort at the start.
This is the minimum level one would use for a normal gravity beer in the
range of 11 Plato.
The beer that stuck was 16.5 P. A minimum number of cells for a beer of
this gravity would be ~17 million cells/ml and a more typical number is on
the order of 20 million cells/ml. So I feel the authors started off by
under pitching. The wort itself was aerated using air via a fish pump and
then inoculated with the starter or so the text seems to indicate. This is
another point where the authors and other brewers can do things to prevent
stuck fermentation. The rule or thumb that I have read and heard about is
that one should increase the oxygen level 1 ppm for each degree Plato above
10 P. If air saturation gives 8 ppm then a 16.5 P wort should be
oxygenated to a level of ~15 ppm oxygen. The authors used air so the best
they could get was 8 ppm. Also wort of this gravity has a lower oxygen
solubility (someone can probably tell us what the conc. was approx)
presenting another disadvantage for the yeast. For those using air a simply
aeration and then pitching is not enough for this gravity of beer. One
needs to aerate for a longer period of time so the yeast can get enough
oxygen to synthesize a maximum level of sterols and unsaturated fatty acids
(UFAs). These yeast are going to have to deal with fermenting a larger
amount of sugar and withstanding stress from higher ethanol levels. Only
if one were to pitch a very large amount of yeast that already had maximum
levels of sterols and UFAs would simply aeration be enough.
The authors took gravity readings at 6 weeks and low and behold the beers
had not fermented out. hmmm. And the authors state "although significant
amounts of viable yeast were present....." My question is how did the
authors determine the yeast were viable? I would presume methylene blue
was used. Methylene blue staining really tells one nothing about the
actual state of the cells other than that they can exclude the dye. In
Brewing Science volume 2 it is stated that MB works well for healthy
cultures but gives highly erroneous results with cultures in poor
condition. A table is presented showing that cells heated at 43 C may show
97% viability by MB but when tested by plate or slide culture show less
than 1% viability after 3 minutes of heating.
The authors decided to pitch more yeast in the amount of "One quarter of
the cultured yeast slurry was added to the RIMS and Infusion mashes and one
half added to the decoction mash." The RIMS and infusion beer reached
terminal gravity "fairly quickly". Not sure what that is but compared to 8
weeks anything is quick. The decoction beer still edged along. I presume
the authors knew the two beers and reached true terminal gravity either via
a forced test or Clinitest. Why did the one beer not finish? It is hard
to draw any concrete conclusions based on the limited N value. But adding
new yeast that may not be at full sterol and UFA level to an environment of
no oxygen, low nutrient levels, some alcohol is a problem any one who
repitches faces. Also at the point in time the authors repitched the
glucose may have all been depleted along with some maltose. The yeast may
have been to stressed by all this. This is by no means a definitive
diagnosis since the other two beers finished "fairly quickly"..
In general it looks like the decoction mashing did something to the wort
sugar profile and nutrient profile that lead to this slow fermentation, but
who knows. My point (and I don't mean to pick on Louis and the others) is
that here we have one guy who has a SABCO unit that was till expensive
when Louis go it a few years ago. Andy Thomas went to all the trouble to
do a triple decoction. These guys put all this time, money and effort into
making these beers and even wrote an article about it. It is my belief
that they and many other could save themselves a lot of grief by directing
some of their money and efforts toward making bigger starters. And I am
sure many people are going to chime in "I made a 1070 beer and it fermented
out in a week ....." Then again we have Charley who wrote: "2 quart
starter from a smakpack of 2206 into a 1.075 Bocktoberfest (layer of yeast
only about 1/8" thick at bottom of starter). It took off with a krausen
within 2 hours - but took 25-26 days to ferment out."
I am sure others can point out things I may ahve missed, since this is a
quick take on things.
And the Megas make 16 P (high gravity brewing) many times a day that
ferments in a few days, and you can do it too. Not that you might want to
exactly follow the time temp process they use. The point being that even a
high adjunct low FAN high gravity wort can be fermented quickly provided
one use proper oxygen and yeast levels. But again even though this may
read like I am being dogmatic I do not mean it to be. Please feel free to
do as you wish and what works for you.
Jim
------------------------------
Date: Sun, 23 Aug 1998 22:24:11 EDT
From: MrMike656@aol.com
Subject: Homegrown hop plugs
I thought I'd pass this trick along - My wife complained that my hop crop
was taking up too much space in the freezer. So, I thought, why not make
plugs? I had a cigar mold lying around, so I took my freshly picked and dried
hops and stuffed them into the mold, and tamped them down with a 3/4 in.
dowel. After a few hours, the oils bind the hops together, and I have several
Churchill sized hop cigars. Easy to store and much easier to weigh than loose
cones.
If you haven't got a cigar mold around, you could probably use a piece of
PVC pipe as a mold.
Mike Maimone
------------------------------
End of HOMEBREW Digest #2806, 08/24/98
*************************************
-------
