---

	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:
  Brian's email is changing ("Brian Dixon.")
  Things going wrong (Graham Sanders)
  peroxide diluting ("Dr. Pivo")
  Basics of Stepping-Up ("Spence")
  Reminder - Eighth Annual Dominion Cup (Frank Timmons)
  Smelling CO2 (Demonick)
  Brewing big beers ("Jim Busch")
  Leaf/Pellet hops for mash hopping ("Paddock Wood Brewing Supplies")
  Bleach again (Bill.X.Wible)
  Mommilies (RCAYOT)
  More on peroxide (Nathan Kanous)
  Big Brew Sign-Up ("Paul Gatza")
  Re: Mack & Jack's African Amber (JDPils)
  Re:  Bad Starters (JDPils)
  diacetyl control ("George de Piro")
  Dr Cones Yeast Replies (Aleman)
  35%H2O2 Danger (James Jerome)
  Yeast propagator ("Pannicke, Glen A.")


* Beer is our obsession and we're late for therapy!

* 18th Annual Oregon Homebrew Festival - entry deadline May 15th
* More info at:  http://www.hotv.org/fest2000

Send articles for __publication_only__ to post@hbd.org

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 FROM THE E-MAIL
  ACCOUNT YOU WISH TO HAVE SUBSCRIBED OR UNSUBSCRIBED!!!**
IF YOU HAVE SPAM-PROOFED your e-mail address, you cannot subscribe to
  the digest as we canoot reach you. We will not correct your address
  for the automation - that's your job.

The HBD is a copyrighted document. The compilation is copyright 
  HBD.ORG. Individual postings are copyright by their authors. ASK 
  before reproducing and you'll rarely have trouble. Digest content 
  cannot be reproduced by any means for sale or profit.

More information is available by sending the word "info" to 
req at hbd.org.

JANITORS on duty: Pat Babcock and Karl Lutzen (janitor@hbd.org)



----------------------------------------------------------------------


Date: Wed, 3 May 2000 22:12:46 -0700
From: "Brian Dixon." <briandixon at home.com>
Subject: Brian's email is changing


I'm going to be doing a change in online services soon, so my email address
will no longer be valid as of Monday, May 8th.  Please use either
briandixon at hotmail.com or brian_dixon at hp.com for now.  Thanks!

Brian

 N44 35' 54"    W123 14' 56"




Return to table of contents


Date: Thu, 4 May 2000 15:16:57 +1000 
From: Graham Sanders <GrahamS at bsa.qld.gov.au>
Subject: Things going wrong



G'day all

In the spirit of all things going wrong its my turn.

Years ago I used to use the 25 litre plastic buckets as fermenters and like
now do my brewing outside, being banished by the better half from the
kitchen and inside the house in general.

Well after spending the better part of the day making a wonderful porter,
there it was sitting nicely in the fermenter.  Pitched the yeast starter,
all is wonderful in the world.  

"nows where the lid" one asks.  "oh inside the house" I quickly reply.  No
problem, in and out I go.  Upon my return wonderful ripples greet me.  A
fearful look confirms a fly doing backstroke laps at a great rate of knots.
After he does 3 laps in front of me I panick.   Got to get him out - "oh
shit where is that spoon", as he turns for another lap.  No spoon, so in
goes my hand and out goes a rather annoyed fly who protests loudly "i'm in
training, how dare you".

Now the mind ticks over, "do I reboil" - no is the answer, got no yeast to
pitch and cant get any.  "yes i'll just laddle off some of the liquid off
the top". A dash into the kitchen and after howls of protect from she who
must be obeyed, out I come with some kitchen utensils.

My German sheperd, Rumpold is always willing to help in these situations.  A
stern "sit" put him in his place.  Well he sees me setting up the kitchen
utensils and being a smart dog works out what I am going to do. Now as I
turn my back he thinks "yes - my tongue will do the job much better, lets
please the master".  

Now I will testify the sounds of Rumpole skimming the top of my wort is not
pleasant, but you cant get mad at him for helping.

Well I gave up.  Put the lid on, into the refrigerator and wait.  Well as
all who have said before, the beer came out fine with all the problems.
Maybe it was the porters ability to hid off flavours, or the big starters I
use I dont know.  But yes brewing can be all forgiving.  It amazes me that
you can really stuff a brew up and it turns out all right, and yet other
times breath the wrong way and its ruined. 


One thing I did change is my type of fermenter.  Old "Rumps" can't drink out
of them now.

Shout

Graham Sanders    



Return to table of contents


Date: Thu, 04 May 2000 09:33:14 +0200
From: "Dr. Pivo" <dp at pivo.w.se>
Subject: peroxide diluting

Wes Smith points out from the highlands (elevation:about 80 meters), the
following regarding diluting 35 percent peroxide:

>  We effectively diluted to 
> around 5% for use but had found that the weaker commercial solutions lost 
> there effectiveness very quickly and we could not predict the reaction as 
> we could from the 35% solution

and...
> Just be aware that weaker (3 or 6% solutions) of H2O2 
> have a definite shelf life at their stated strength.

And I am expecting that Wes and his mates, were like myself compounding
this problem by diluting with "regular water"... there's always
"something" in a non deionized water that will kick off the oxygen
liberation movement.

That's why I like to have a concrete floor handy for testing "older"
mixes... I figure if it "hisses" it's good.

I have, by the by, already warned Wes about other possible uses for pool
cues, and would recommend that if he drops his change at the bar, just
leave it.

I first became aware of this problem when Jill wrote me privately,
asking if I knew of any good method for removing the blue chalk marks in
Phil's undies.

I of course, recommended peroxide.

Dr. Pivo


Return to table of contents


Date: Thu, 4 May 2000 08:35:55 -0400
From: "Spence" <drwlg at coollink.net>
Subject: Basics of Stepping-Up

I have been lurking the HBD for several months now, and betwixt the tongue
and cheek and follderall I have gained a fair amount of knowlege that has
prompted me to move to a partial grain boil... and it worked and tasted
great!  (Don't know if I have the intestinal fortitude, or patience to go
all-grain.)

I also went with a liquid yeast this time and was quite pleased at the
encouragement of Wayne Love.  (By the way, Wayne... tax season is over...
come out, come out wherever you are!  Drop me a note to my new address...
drwlg at coollink.net)

Dr. Cone's articles were great... and I even understood some of them!  Ha
ha!  What I would like is for some kind soul to give an account of the
proper step by step way to "step-up" your starter.  Give details so I know
if I'm screwing things up yet!  Include procedures for both liquid and dry
yeast if possible... the uneducated of us are ready for more!

Spence Graham

(If you're not bleedin' you're not having fun!)



Return to table of contents


Date: Thu, 4 May 2000 06:55:54 -0700 (PDT)
From: Frank Timmons <francis0001 at yahoo.com>
Subject: Reminder - Eighth Annual Dominion Cup

Just a quick reminder that the James River Homebrewers
will be hosting the Eighth Annual Dominion Cup
Homebrew Competition on Saturday, May 20, at the
Legend Brewery in Richmond, VA. Entries are still
being accepted through May 18. E-mail me back for
entry info. I still have a need for a couple of
judges, preference will be given to those in the BJCP program.

__________________________________________________
Do You Yahoo!?
Send online invitations with Yahoo! Invites.
http://invites.yahoo.com


Return to table of contents


Date: Thu, 4 May 2000 07:18:42 -0700
From: Demonick <demonick at zgi.com>
Subject: Smelling CO2


From: kevin m mueller <kmmuellr at engin.umd.umich.edu>
>I put my nose to the neck of the 2.5 gal carboy that I was using and
>the smell nearly knocked me over.  Its a hard smell to describe, but
>it was very sharp on my nose.

If it was tingling, burning, or otherwise hurt, it was the almost pure
CO2 in the headspace of the carboy.  CO2 plus the water in your nose
and/or mouth yields carbonic acid which at the levels we are talking
about is an irritant.  Don't worry, you'll live.

Cheers!

Domenick Venezia
Venezia & Company, LLC
Maker of PrimeTab
(206) 782-1152  phone
(206) 782-6766  fax orders
demonick at zgi dot com

FREE PrimeTab SAMPLES! Enough for three 5 gallon batches. Fax, phone, or 
email: name, shipping address (no P.O.B.) and phone number. (I won't 
call. It's for UPS in case of delivery problems). Sorry, lower 48 only.




Return to table of contents


Date: Thu, 4 May 2000 11:13:13 +0000
From: "Jim Busch" <jim at victorybeer.com>
Subject: Brewing big beers

Bob asks about brewing big beers and yeast/oxygen.  BTW, glad you 
like our Storm King!  Stormy is right around 10% ABV and achieves 
this through a fairly normal pitching and fermenting process.  A few 
tips:

be sure to rest big beers mash in the 140s for good fermentability.
be sure to pitch a huge quantity of yeast mass.  Best way to do this 
if you dont have access to slurry from a micro, is to brew up a 
normal gravity beer, say 12-15P, like an ESB or pale ale and ferment 
this to completion.  Rack off and reuse the entire yeast cake for 
your big beer.
pump oxygen into the chilled wort at pitching time.

Provided you get enough yeast biomass into the wort and fully 
oxygenate, you can easily produce clean 10% beers without additional 
oxygen added later.

Prost!

Jim Busch


Return to table of contents


Date: Thu, 4 May 2000 10:13:11 -0600
From: "Paddock Wood Brewing Supplies" <orders at paddockwood.com>
Subject: Leaf/Pellet hops for mash hopping

Trevor.Hyde at marquette.edu reports that he used 2 oz of Kent Goldings LEAF
hops in his mash and didn't get significant aroma or flavor.

We've found that pellet hops work best for mash hopping.


Stephen Ross -- "Vitae sine cerevisiae sugant."
______________________________________________
Paddock Wood Brewing Supplies, Saskatoon, SK
orders at paddockwood.com  www.paddockwood.com



Return to table of contents


Date: Thu, 4 May 2000 13:41:54 -0400
From: Bill.X.Wible at QuestDiagnostics.com
Subject: Bleach again




Jeremy Bergsman <jeremybb at leland.Stanford.EDU> writes:

>It is often said, most recently by Bill Wible, that bleach requires a lot of
>rinsing.  Why is this?  I have measured the effluent from my carboy after
>rinsing using the chlorine test strips and it seems to follow the normal
>rules of dilution.  Is the bleach supposed to be sticking to the glass or is
>it more of a loaves and fishes situation?
>
>As for rinsing with tap water, I agree that this seems silly, but I boil
>water in a small saucepan with a good lid and this is enough to rinse 2
>carboys.  Cheap, easy, fast, cheap, effective, and cheap.

Well, I'm not a chemist, Jeremy, but what I know about homebrewers
and their professions tells me that there are very high odds that somebody
else who is reading this is.

I can't give you scientific theory as to why bleach has to be rinsed well,
other that the fact that it is a chemical that leaves residue.  And I'm
not 100% positive about that.

 I remember reading someplace that chlorophenols are detectable in beer
by the 'average' person at extremely low levels.  (Isn't it funny the 'average'
person can't seem to taste sulfur, though)  : )

Bleach can contribute chlorophenols.  That's all I know.  That's all I need
to know.   I stopped using it awhile ago.  I'm not here to argue.  If you
have been using it and are getting good results, then I won't tell you to
stop using it.  You must be doing it right.  Just be aware that if you ever
come up with a beer that has a medicinal or phenolic taste, that could
be the cause.




Return to table of contents


Date: 04 May 2000 10:04:52 -0400
From: RCAYOT at solutia.com
Subject: Mommilies

     Okay, here we go, Grant said:
     
     "Grant W. Knechtel <GWK at hartcrowser.com>
     Subject: Bleach vs. Stainless - Momily?
     .....
     IMHO this doesn't qualify as a momily.  Household bleach will indeed 
     pit stainless.  I have seen stainless completely corroded through, 
     albeit at long contact times and high concentrations."
     
     Isn't THIS EXACTLY what a momily is?  I mean sure someone you know 
     told you about the chemistry, and you saw something that happened 
     after "long contact times and high concentrations".
     
     I just want everyone to know I have used bleach for years, have been 
     kegging for a couple of years and I use bleach to sanitize my kegs, 
     1/4 cup in 5 gallons water, invert the keg, bleed out the air in the 
     gas and liquid tubes.  Leave for up to two or three days, rinse, no 
     problems.  
     
     Sure there are better products, I should probably get some, but 
     homebrewers should know that they can use bleach safely on SS.
     
     However, don't use it on Aluminum!
     
     So is the bleach a momily or not?
     
     Roger



Return to table of contents


Date: Thu, 04 May 2000 13:11:43 -0500
From: Nathan Kanous <nlkanous at pharmacy.wisc.edu>
Subject: More on peroxide

Hey beermeisters.  Here's some testimonial on peroxide as a sanitizer.
http://www.execpc.com/~mjstouff/articles/vinegar.html
nathan in madison, wi


Return to table of contents


Date: Thu, 4 May 2000 12:57:19 -0600
From: "Paul Gatza" <paulg at aob.org>
Subject: Big Brew Sign-Up

Hi everyone. Thanks to everyone who has registered for the AHA Big Brew. For
those of you who are participating who have yet to register, here's a link
to the registration page http://beertown.org/AHA/BB2000/bigbrewreg.htm. Gary
and I are hosting site #97 at the Sunshine Meadery, just west of Boulder,
with good friends, food and horseshoes and Kentucky Derby Party. I don't
expect it to match the huge extravaganza planned for the Barr House Brewery
in Michigan, but if you're in the Denver-Boulder area, you're welcome to
come on by. The simultaneous toast is at 1 p.m. eastern, noon central.

A quick review of the registered sites has listings for all over the U.S.,
and Poland, England, South Africa, Japan, Germany and Austria. Cheers to all
Big Brewers.

Paul Gatza (mailto:/paulg at aob.org)
Director, American Homebrewers Association
736 Pearl St., Boulder, CO 80302        voice(303)447-0816 x 122
fax (303) 447-2825
Join the AHA at http://www.beertown.org





Return to table of contents


Date: Thu, 4 May 2000 15:44:06 EDT
From: JDPils at aol.com
Subject: Re: Mack & Jack's African Amber

Nathan,

Wanted to know about Mack & Jack's African Amber.  The Cascade Brewer's Guild 
was given a nice reception and tour at the brewery in Redmond, WA.  It was 
about two years ago, so I will pass on was I recall.  They started out very 
small and have grown dramatically distributing their products in kegs only to 
local establishments in the Puget Sound region.  The three beers I have 
tasted are AA, Seringetti Wheat, and Black jack Porter.  All are fine beers.  
The beers are fermented very quickly and crash cooled, then kegged.  The 
distribution process usually allows for two weeks of aging.

The beers are also 'big' for their styles and I think this allows them more 
margin on such a quick process.  I often wondered what would happen if the 
Amber was lagered for a few weeks.

As for recipes I do not have any information.  Hope this helps.

Cheers,

Jim Dunlap


Return to table of contents


Date: Thu, 4 May 2000 15:44:08 EDT
From: JDPils at aol.com
Subject: Re:  Bad Starters

 Chris,

The only DME I have found which produces a healthy starter from any yeast 
source (smack pack, White Labs, previous batches) is Munton & Fison.  I have 
not tried Breiss, but Laaglander is bad.  Also, after the local brew shop 
burnt down I went to a couple others and got 'American' and 'English' which 
both produced poor quality starters.  With these extracts my starters showed 
pressure in the air lock and only bubbles if you shok the container.  

I would also watch your pitching temp and SG.  Shoot for no higher than 75F 
and 1.050, IMHO.

Cheers,

Jim


Return to table of contents


Date: Thu, 4 May 2000 15:48:08 -0400
From: "George de Piro" <gdepiro at mindspring.com>
Subject: diacetyl control

Hi all,

Ryan writes regarding Ringwood yeast and diacetyl.  He mentions that Wyeast
recommends a diacetyl rest after fermentation.  The following is some
general buttery babble I recently wrote for the IBS Brewers Forum.  It
should answer Ryan's question:

Ringwood yeast is a notorious diacetyl producer, but the brewer can do
things to keep it at reasonable levels.  Of course, "reasonable levels" is a
personal thing, but be aware that diacetyl is something that only gets
bigger with time, so if you like the level of butteriness in your beer 3
weeks from brewday, drink it fast and store it cold.

Diacetyl production is proportional to yeast growth, so pitching a lot of
yeast may help reduce the final level of diacetyl.  The yeast need to be
healthy as well:  diacetyl isn't actually made by yeast (see below), and the
precursor is converted to diacetyl at a relatively slow rate.  If your yeast
have crapped out (techie term), they won't be able to absorb the diacetyl.

How does one know if their beer is going to end up with high diacetyl
levels?  There is a very simple test requiring no lab equipment at all that
can answer this question for us.  Before we get to that test, I will quickly
review how diacetyl is formed by yeast (a proper understanding of how
diacetyl is formed and reduced will lend clarity to the test procedure).

Yeast do not actually make diacetyl, they make a compound called alpha
acetolactate (AAL).  It is this chemical that is oxidized to diacetyl.  This
oxidation is relatively slow at fermentation and lagering temperatures, but
is conveniently accelerated by higher temperatures.  That is why a diacetyl
rest works for lager brewers:  the fermentation is warmed to the low 60's F
for several days to allow the faster conversion of AAL to diacetyl.   The
yeast will then consume the diacetyl, thus eliminating it from the beer.  If
an appreciable amount of AAL makes it into the final package and there is no
active yeast to consume it, the beer will become buttery with time as the
AAL oxidizes.  The thermal abuse a beer experiences in the distribution
chain will accelerate this.

The following procedure will tell you if you have excess AAL in your young
beer:

After fermentation is complete, remove 2 small samples of beer from the
fermentor.  Aseptic technique is not necessary (other than not contaminating
the fermentor).  Put each sample into a jar that you can fit with a lid (a
Mason jar would work well).  Put one sample in a hot water bath and heat to
about 140-150F for 20-30 minutes.  Keep the other sample at room temperature
(or less) during this time.

Cool the heated sample down to about the same temperature as the room
temperature aliquot by putting the jar in an ice bath.  Remove the lids and
smell them both.  You will find one of the following results:

A.  If the cool sample does not smell of diacetyl, but the heated one does,
then you have an excess of AAL in the young beer that will be converted to
diacetyl in your packaged product.

B.  If both samples smell clean, yet the product develops a buttery note
over time, it is likely that pediococcus is the culprit.  (Note:  If both
samples are devoid of diacetyl and you are a lager brewer, you need not
perform a diacetyl rest with this batch.  Why waste time?)

C.  If both samples smell of diacetyl, and your fermentation is fairly warm,
it could be that the yeast flocculated so early that it could not absorb the
diacetyl that was produced toward the end of fermentation.  It could also be
that bacteria or respiratory deficient mutant yeast are at work.  Plating
the beer on differential media will help you to solve such microbial
quandaries.

If result "A" is obtained, you are not doomed to a buttery packaged product.
If you are brewing a lager, now is the time to do that diacetyl rest.  If
you are brewing ales, simply allowing the yeast more contact time with the
young beer will reduce the diacetyl as it is formed.

You absolutely need active yeast in contact with the beer to reduce the
diacetyl.  If you are using a very flocculent yeast, like the Ringwood
strain, there may not be enough yeast left in suspension to reduce the
diacetyl.  In this case, you need to either use a less flocculent strain, or
kraeusen with fresh, active Ringwood yeast.  You could try rousing the
yeast, but without fresh wort to consume, the yeast may be pretty inactive
and uninterested in deflocculating.  The oxidation of the young beer that
can be caused by rousing the yeast is, of course, detrimental to beer
quality.

Some of you might be wondering why I suggest taking two separate samples of
beer, rather than just smelling the fresh sample before heating it.  This is
done because if the amount of diacetyl is not obvious to you, you are much
more likely to tell the difference between the two samples if memory is not
involved.  You can also conveniently invite others to help you as "taste
panelists."

Have fun!

George de Piro

C.H. Evans Brewing Company
at the Albany Pump Station
(518)447-9000
http://evansale.com (under construction)

Malted Barley Appreciation Society
Homebrew Club
http://hbd.org/mbas

George de Piro

C.H. Evans Brewing Company
at the Albany Pump Station
(518)447-9000
http://evansale.com

Malted Barley Appreciation Society
Homebrew Club
http://hbd.org/mbas



Return to table of contents


Date: Thu, 4 May 2000 20:52:18 +0100
From: Aleman <Aleman at brewmaster.demon.co.uk>
Subject: Dr Cones Yeast Replies

Hello All,

I was stunned by the quality of the replies from Dr Cone, so Quickly
mailed Rob Moline to ask if there would be any objection to me
collecting the replies together and putting them on my web site.

At the time he responded that he was going to do that and post them on
the Lallemand site, however as usual, time for him is at a premium. I
received a mail from him today telling me that I could go ahead. (Thanks
Rob, No need to apologise, my plans often change through lack of time at
the moment)

So I would like the originators of the questions to give me permission
to use their questions on the web site. They will get full attribution,
as will Lallemand and Dr Cone. If any of you do object please email me

Oh and Pat, will you give your permission for the articles to be so used
on behalf of the HBD Gods?

Thanks in advance for your needed co-operation.

- -- 
Wassail ! 

The Scurrilous Aleman 

Schwarzbad Lager Braueri, Blackpool, Lancashire, UK

Reply to Aleman at brewmaster dot demon dot co dot uk

ICQ 46254361


Return to table of contents


Date: Thu, 04 May 2000 20:52:45 -0600
From: James Jerome <jkjerome at bellsouth.net>
Subject: 35%H2O2 Danger

Uh, Brew-types,

John Schnupp's comments from the Dirty Laundry Brewery are FOR REAL. 
Aside from some really great cleaning effects, a 35% hydrogen peroxide
solution is a real hazard.  If it will oxidize (very quickly and deeply)
the proteins in your skin, and it will go berserk on more readily
oxidized stuff.  Check out any organic chemistry textbook under standard
oxidizing reagents.  

Be advised that any organic solvents in the vicinity are particularly
susceptible to the oxidation by H2O2..  It produces oxygen free radicals
in sufficient quantity to go on a mission to find something to make go
BOOM!  If the stuff comes in contact with pesticide residue or
unsaturated organic compounds and there just happens to be a
catalytically active metal around (lots of them)...BAD THINGS can
happen.  The bad things are are great deal worse than a boil-over or an
overpressuirized bottle letting loose.  

Please use less than 5% solutions for anything.  Don't store or handle a
35% H2O2 solution without the serious precautions required.  Pardon my
language, but I shit you not...35% H2O2 has the potential to end your
brewing experience permanently.  

If anyone is really curious, go to <www.sigmaaldrich.com> and look up
hydrogen peroxide's MSDS (free). 4 milliters of 30% strength ruined a
laboratory hood and ~$1500 US dollars of glassware, and came close to
getting me kicked out of graduate school.

James Jerome, Ph.D.
Senior Research Scientist
Chattem Chemials, Inc.
Chattanooga, TN


Return to table of contents


Date: Thu, 04 May 2000 09:14:52 -0400
From: "Pannicke, Glen A." <glen_pannicke at merck.com>
Subject: Yeast propagator

On 03 May 2000 Roger Ayotte wrote of Yeast propagator:
   
>Well, I think that is where you are going a littel awry, those yeast 
>cuts are discussed in the context of collecting yeast from a full size 
>brew.  In the case of growing yeast for homebrewing from a slant or 
>smack pack, you don't have to worry about that.  If you set aside some 
>wort from a previous brew or make up some from DME, you can always 
>filter it (use a coffee filter) after the hot and cold break  form and 
>then can it and get trub free media.  

I learned the coffee filter trick after much sighing from dumping the last
inch of wort laden slop down the drain for every batch.  It works great and
I pressure can the leftovers.  I do get some additional trub after canning
though.  I guess the high heat.  Am I the only one?  Anyway, I've gotten a
few comments along the lines of the yeast fractions being for main ferments.
The bottom cock can be there if you want it.  I never get 1 gallon of
leftovers so I'll have to supplement it with some malt extract anyway.  It
can be used to dump trub & hop particulates, or just there to facilitate
easy collection.  I have seen some layering of yeast in a large flask
starter similar to what is seen in a main ferment.  Usually only two layers,
which I think is comprised mostly of dead cells and a bit of trub.
          
>Be easily sterilized, not just sanitized.  Big difference here, it 
>is important especially if you start from slants where the innoculum 
>is really small.

This is a tough one for plastic, which then leaves us with metal and
glass...  But those are difficult for everyone to work with.  I would not
suggest inocculating a 1 gallon starter from a slant.  Maybe from a smak
pack.  Definately from a pitchable vial.  I'd use sucessive 10X step ups
from a slant to 4 L (~1 gallon).
     
>Should be able to add nutrient and oxygen (air) 
>without contaminating the starter.
 
>should be able to be agitated, preferably magnetic stirrer.

Being a former lab rat, I would love this (shaker plate even better!).  But
it doesn't work with a conical bottom.  Brad Miller turned me on to the
spinner flask.  Conical bottom with a suspended angled blade driven by a
magnet.   They're used in some bioreactor designs and come in many sizes.
If they had a bottom cock and were cheaper, they'd be perfect.


Carpe cerevisiae!

Glen Pannicke
http://www.pannicke.net
"He was a wise man who invented beer" - Plato


Return to table of contents

---