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HOMEBREW Digest #0194
HOMEBREW Digest #194 Tue 04 July 1989
FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
Rob Gardner, Digest Coordinator
Contents:
Re: Homebrew Digest #191 (July 01, 1989) (Paul Perlmutter)
Bleach, etc. (ROSS)
disinfectants ("1107-CD&I/VIRUS DISEASES")
Brewing Odds and Ends... ("Lance "Satchmo" Smith")
Send submissions to homebrew%hpfcmr@hplabs.hp.com
Send requests to homebrew-request%hpfcmr@hplabs.hp.com
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Date: Mon, 3 Jul 89 09:49:51 mdt
From: Paul Perlmutter <paul@heaven>
Subject: Re: Homebrew Digest #191 (July 01, 1989)
> After 11 years of brewing, I use only hop flowers, and
> avoid pellets when I can. ....
> I do this because I'm really into the noble aromatics, and it sure shows
> up in a fresh bale of kent goldings!
I am currently living in Bristol, England and recently took a tour of
the main Courage brewery here, where they brew the beer for their casks.
(Their brewery for bottled beer is located east of Redding.) Their
casks are used to pump their famous "Directors Bitters" which is one of
the most popular beers in England. I actually didn't learn too much,
because their process is so automated, and so spread out over the
country. However, I did find out something interesting in regards to
using hop pellets versus fresh hop flowers. They use exclusively hop
pellets because they are so easy to handle, store so well, and are so
convenient to ship. They found (according to their very knowledgable
staff) that fresh hop pellets are not in any way inferior to fresh hop
pellets.
After the tour, they invited us to join them in their hospitality suite,
an old gorgeous pub, across the street from the main building. The pub
is for guests of Courage brewery only, and is quite posh. They have
Courage Director's on tap (of course) and I had some superb beer. It
was fresh and delicious!
Paul Perlmutter
------------------------------
Date: Mon, 3 Jul 89 09:30 EDT
From: ROSS@mscf.med.upenn.edu
Subject: Bleach, etc.
Date sent: 3-JUL-1989 09:14:14
Concerning the issues of sterilization and sanitizing. Although it has
been awhile since I was in school and had a course concerning these topics, I
do remember some of the important issues.
The first is that time is a very important concept. Whether you are
using an autoclave to heat sterilize or are using bleach, the idea is to kill
the organisms that can contaminate your beer. We used to have a liquid
sterilizing solution at school that students would use to sterilize some of
their dental equipment with. It was constantly stressed that the instruments
had to soak for a certain length of time (which allows the chemicals to do
things like break apart the cell walls of the organisms). If you just dip
and rinse, you might as well just rinse your stuff with sterile water.
The same applies to heat sterilization where the items to be sterilized must
remain in the autoclave for a certain length of time.
Rinsing in itself has been proven to be a good way to clean things.
When surgeons scrub for surgery, the majority of the cleansing is done
mechanically (scrubbing) and by rinsing.
Therefore, I doubt the effectiveness of using B-brite for 15 seconds
and then rinsing. I feel that in this case it is really the rinsing that
is doing the work. It also sounds (although I never used B-Brite) like
B-Brite is some sort of hydrogen peroxide solution. Peroxide is something
that you can buy for next to nothing at a pharmacy. I also know that it
is being used in some cleaning products for soft contact lens and works
quite well.
Anyway, I think the bottom line is that you want to keep things as
clean as possible, and often times, even without complete sterilization you
can make a superb homebrew.
--- Andy Ross ---
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Date: 3 Jul 89 16:42:00 EST
From: "1107-CD&I/VIRUS DISEASES" <henchal@wrair-emh1.army.mil>
Subject: disinfectants
Recently, there have been several inquiries concerning
sanitation methods. I offer the following insights:
1. Few chemical methods available to the homebrewer can result
in STERILE utensils. Sterile means devoid of any living
organisms. An example of a sterilization method is the use of
steam-based, sterilizers (autoclaves) which do their work at 15
lbs of pressure 212 degrees F for 20 minutes. For the
homebrewer, he can create these conditions only in a pressure
cooker or pressure canner. Most methods are only SANITIZING. To
sanitize means to reduce (or prevent the growth of) the microbial
population to an acceptable level. An example of a sanitizing
method is pasteurization which eliminates target organisms in
food products, but does not sterilize.
2. Methods of sanitation and sterilization should be applied
separately from those meant to merely clean utensils. A rule in
the food industry is to CLEAN first, SANITIZE second. One reason
for the rule is that disinfectants must be able to penetrate the
material you are trying to treat. Soil or residues can actually
protect microbial contaminants from the action of these agents.
3. Bleach (usually 5.25% sodium hypochlorite) is probably one of
the most effective disinfectants available to the homebrewer.
However, most folks use as much as 10 times as required to
disinfect their materials. Chlorine in aqueous solution is
effective in concentrations of 5 to 50 parts per million (ppm).
As a general rule, the bacteriocidal action of chlorine decreases
as the pH increases, and increases as temperature increases.
Chlorine solutions are generally more effective at warm
temperatures, but they are less stable. The hardness of the
water generally has no effect on the bacteriocidal action of
chlorine solutions. A review of the current literature reveals
that as little as 0.2 ppm was effective in 30 seconds against
most vegetative microorganisms. However, some microorganisms are
more resistant. Most spore-forming bacteria (bacillus and
lactobacillus species) required 120 minutes at chlorine
concentrations of 2-3 ppm. Fungi required 30-60 minutes at 100
ppm. The recommendation of the US Public Health Service for the
dairy industry is that hypochlorite solutions of at least 50 ppm
of available chlorine should be used for sanitizing utensils at a
minimum of 1 minute exposure at 75 degrees F.
fluid oz bleach ppm, available
per 5 gallons water chlorine
__________________________ _______________
0.062 (a little more than
1/3 tsp) 5
0.31 (a little less than
2 tsp) 25
0.62 (about 1 and 1/4 tbsp) 50
1.24 (about 2 and 1/2 tbsp) 100
4. Dr. Michael Davis, University of California-Davis recommends
1/4 to 1/2 oz per 5 gallons of water and a contact time of 15-20
minutes. At this concentration, rinsing with water is not
required as long as the utensils are allowed to drip dry.
This is where I think Charlie Papazian misleads people. He
recommends bleach concentrations which are too strong and then
reommends water rinses. Water rinses are ok, but if the
temperature of the water is less than 180 degrees F, you risk re-
contamination of the utensils. (Most water supplies do have some
microbial contaminants. Using the hottest tap water available
usually only results in giving the microbes a sauna bath.)
5. B-Brite is a popular disinfectant, but you MUST rinse the
utensils after treatment.
Some readings:
The Practical Brewer. Edited by Harold M. Broderick, second
editon, 1977, Master Brewers Association of the Americas,
Madison, WI 53705
Disinfection, Sterilization,and Preservation. Edited by S. S.
Block, third editon, 1983, Lea & Febiger, Philadelphia, PA.
"Microbial Controls" by Michael Lewis, In the Best of Beer and
Brewing, pp. 205-226, 1987, Brewer Publications, Association of
Brewers, Boulder, CO 80306.
Those with questions or comments are invited to write to me at my
EMAIL address.
Erik A. Henchal
<Henchal@WRAIR.ARPA>
Oh, by the way Everclear or grain alcohol is an effective disinfectant
also. It is more effective at 70% than undiluted, but it has practically
no effect on microbial spores and less penetrating (because it evaporates
quickly) than aqueous chlorine solutions. I don't recommend that you
use alcohol to disinfect fermentors or utensils, but you can use it to
sanitize work areas effectively.
Last note: Acidic aqueous chlorine solutions are really tough on
stainless steel. In the laboratory, we often disinfect with bleach, but
then rinse thoughly with water, followed by 70% ethanol. In this case,
the bleach is a cleaning agent not the sanitizer.
Henchal
------------------------------
Date: Mon, 3 Jul 89 22:30:21 CDT
From: "Lance "Satchmo" Smith" <lsmith@umn-cs.cs.umn.edu>
Subject: Brewing Odds and Ends...
Just a few things I wanted to comment about.
Yellow Dog Amber Extract: Someone posted about this and I noted a few
responses. I'm very curious to find out what people's reactions
are after they've used it. I made a batch of mild using Yellow Dog
and the results weren't very good. I'm not sure it was the extracts
fault, but I must say that it was the thinnest extract I've seen. I
understand that Alexander's is occasionally very thin and Yellow Dog
is made by the same folks. Anyone open & use Yellow Dog yet? Did I get
a bum batch or is my recipe just poor?
Home Brewer of the Year: First thanks to Mr Homer (do I have that right?) for
posting the results for those of us too busy with finals to attend the
conference (you might mention some of us perpetual students aren't done
with school until mid-June to CP and company. I imagine there are some
faculty members that have the same problem). I'm already looking forward
to possible recipes. Now how is Boulder going to come up with enough
exotic yeast to produce a batch of the best of show? Or was that just
for a certain category?
The Scientific Basis of Mr "Relax Don't Worry": I thought it was interesting
two people wrote in before and after their first homebrew. Is there
a reason for you to worry? Sure, you can worry about anything, but it
won't be a very fun hobby if you do. I still worry a little with each
batch before the yeast shifts into high gear. Anyway Charlie's
instructions are reasonable and certainly better than the ones you'll
find on the extract wrappers. Just remember that people who had no
concept of bacteria, yeast or sanitation were producing good beers in
the past. Most of the time small mistakes won't hurt you and only
through experience will you learn to avoid them. The best advice is
to find a system and use it for awhile. Every author has different
advice (the blow-off debate still rages on) so don't try a bunch of
different methods at first. Once you've made a few batches and know what
to expect, then you might start trying different fermentation schemes
or ways of adding adjuncts.
------------------------------
End of HOMEBREW Digest #194, 07/04/89
