HOMEBREW Digest #194 Tue 04 July 1989

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		Rob Gardner, Digest Coordinator

  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")

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---------------------------------------------------------------------- Date: Mon, 3 Jul 89 09:49:51 mdt From: Paul Perlmutter <paul at 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 Return to table of contents
Date: Mon, 3 Jul 89 09:30 EDT From: ROSS at 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 --- Return to table of contents
Date: 3 Jul 89 16:42:00 EST From: "1107-CD&I/VIRUS DISEASES" <henchal at 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 at 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 Return to table of contents
Date: Mon, 3 Jul 89 22:30:21 CDT From: "Lance "Satchmo" Smith" <lsmith at 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. Return to table of contents
End of HOMEBREW Digest #194, 07/04/89
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