HOMEBREW Digest #2835 Mon 28 September 1998

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		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

  building a stainless steel cylindroconical fermenter (MarkETerry)
  Clinitest (kathy)
  Festibiere de Chambly / Conical Fermenter (Cynthia Pekarik)
  To crush or not to crush? (Cas Koralewski)
  KISS HERMS (WayneM38)
  Mash Out / Philosophical aside (Domenick Venezia)
  Not again... ("Doug Otto")
  McEwan's yeast and YeastLab IDs (Jeff Renner)
  Oats are not rye (michael w bardallis)
  Update: Masters Championship of Amateur Brewing (Louis Bonham)
  potatoes and mash out ("silent bob")
  Please AL, "spit the hook" ("Michael Kowalczyk")
  GFCI receptacle for fridge (Seth Goodman)
  DIabetic Meters for Wort Glucose measurement ("Steve Alexander")
  re: Stability of yeast on slant ("Steve Alexander")
  re Osmotic Shock/Microwave ("Steve Alexander")
  Re: Stability of yeast on slant ("Mort O'Sullivan")
  Malting, Rye Beer and Mashout (Dan Listermann)
  Clinitest Test ("David R. Burley")

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---------------------------------------------------------------------- Date: Sat, 26 Sep 1998 09:30:17 EDT From: MarkETerry at aol.com Subject: building a stainless steel cylindroconical fermenter Has anyone got any plans for building one of these monsters? I'm trying to "persuade" my father-in-law to build one for me. That is after he's built my malt mill and boiling kettle!!! Return to table of contents
Date: Sat, 26 Sep 1998 08:21:47 -0500 From: kathy <kbooth at scnc.waverly.k12.mi.us> Subject: Clinitest Clinitest def. a test for glucose on cigars developed by K. Starr jim booth, lansing, mi Return to table of contents
Date: Sat, 26 Sep 1998 10:33:28 -0400 From: Cynthia Pekarik <74163.1163 at compuserve.com> Subject: Festibiere de Chambly / Conical Fermenter Message text written by Posting Address Only - No Requests >< Hello Brew Folks, I had a funnnnnn time three weekends ago at Festibiere de Chambly, Quebec which is 25 minutes south of Montreal. This festival happens on the treed grounds surrounding a restored french fort facing rapids on the Richelieu river; small tents housed micros & distributors.......you could purchase a glass in your fav shape/brew logo at the festiboutique for your beer prominade. Wandering groups of musicians in period dress played at path intersessions and a small main stage beside the river. Food booths with goodies such as unpasterized cheese trays, BBQ sausages, smoked beef jerky & frites. Jugglers, face-painting, falconry for the little people. One moment found me sitting riverside with my feet dangling in the water sipping stout "..." TOO GOOD. BEER......Quebec has some fine brews; IMO the most fertile beerdom in Canada. (sorry B.C.) Many belgian style ales made locally with a good springling of english pales, ambers and stouts. Fruit beers too. T. I. V. M. (tents i visited most) *=* McAuslan - St. Ambriose pale ale & oatmeal stout. <<!!!! Trappiste - Orval, Chimay, Rochefort, Westmalle, La Trappe, Westvleteren. Brasserie du Nord - Rousse (amber ale), Noire (stout), Champs (strawberry). Unibroue - all unique....Maudite & Fin de monde <<!!!! Brasserie Brasal - Hopps brau lager Vermont Pub & Brewery - smoked porter, IPA and more and more anD MORE!! It is very refreshing to attend a beer fest where people of all ages; many with kids gather for fun. I know maybe 10 words of french but this wasn't a problem; most tap-persons knew enough english & were very friendly or Big smile & point, Merci. I know where I will be first weekend of sept 99!! P.S. ATWATER MARKET in Montreal is a pleasant stroll; food galore & cheese shop with good selection of local beer. Long live the Quebec culture ........... Canada would lose if we separate!! - --------------------------------------------------------------------------- - --------------------------------------------------------- For you people with stainless steel fetishes! These guys had a booth at Chambly. Stainless Steel Specialists of Boisbriand, Quebec; make brewery equipment (7 barrel brewery in New Hamp) and now a homebrew system complete with 50 litre conical fermenter. The 3 vessel gravity fed system with strong built rack ( tree style) had the following stuff. HLT - thermometer well, sight tube, heated by 220 volt element. MT - thermometer well, perforated SS screen, rotating sparge arm. KETTLE - thermometer well, sight tube, screen, 220 volt element with SS protective cover. Pump Conical Fermenter - 50 litres, big enough manway to get inside with ease, thermometer well, CO2 line in, 2 cone drains - one at cone bottom and one half way up the cone, with counter flow W.Chiller enclosed in a SS plate attached to inside wall. The electrics looked all heavy duty and neat. I was told the whole package was $2000 can; the fermenter alone approx. $500 to $600 can. The company has just got into this home brew market and are willing to build the system to your desire. I'd love the fermenter under my christmas tree! I have no affiliation with this company aside that I'd kill for that fermenter. Larry Kress RR # 22, Station Preston, Cambridge, Ontario, Canada Return to table of contents
Date: Sat, 26 Sep 1998 10:49:54 -0400 From: Cas Koralewski <caskor at primenet.com> Subject: To crush or not to crush? I am going to be making an Imperial Stout shortly. I have heard of, and read about, a few different ideas concerning how to handle the roasted grains. One was to crush along with the other grains and mash as usual. Another was to mash but not crush. Another was to crush and/ or not crush and add to the mash towards the end of the mash cycle. Confused? You betcha! Considering the cost/time involved with making an Imperial Stout, and the fact that I desire to produce an excellent stout, which way should I go? Thanks, Cas Return to table of contents
Date: Sat, 26 Sep 1998 12:13:03 EDT From: WayneM38 at aol.com Subject: KISS HERMS << I developed a HERMS system about a year ago and couldn't be happier. As far as returning the heated wort to the MLT you want to be careful not to introduce oxygen into the wort. I built a H return with 45 degrees. elbows at the ends to gently return the wort to the MLT. This works quite well as long as you are careful to purge all the air out of the return. If you have sufficient surface area for the heat exchanger and a good flow rate you can raise the temperature 1.5 - 2 degrees. per min. I generally maintain the HLT containing the heatexchanger at 180 degrees. This has worked quite well and achieves conversion in about 30 minutes but continue to hold for a period of 1 hour. I built in an electric bypass valve to continue to recirculate the wort bypassing the heatexchanger to give me the temperature control I desired. When the valve is energized the wort flows through the heatexchanger and bypassed when the valve is de-energized. This facilitates the addition of electronic controls to raise and maintain the temperature as needed to do a step mash or to hold the temperature of a infusion mash. I decided to divert the wort from the heat exchanger instead of cycling the pump to raise and maintain the temperature allowing the pump to run consistently, maintaining an even temperature throughout the grain bed. This will also add a lot of life to the pump. >> I too built a RIMS system using the HERMS system this spring. My system has a similar return manifold design and have similar conversion and temp boosts data. 83% effciency and rising with each batch. I am very, very, very happy with the HERMS design. It exceeded my expectations. With my design, I wanted to keep the system as >simple< (read NO electronics) as possible and still keep temps consistant with minimum intervention. After a few re-designs my final >minimal< design used just two ball valves on the outlet side of the pump. Flexible hoses with quick connects are used for external plumbing. I mash in and start the recirculation with the main recirculation loop. After the temps stabilize, the temp boosts are just a matter of opening the heating loop ball valve until temps are back up. The wort return manifold is shared by both the heating loop and recirculation loop. I leave the recirculation loop open for the entire 60 min mash. The pump is always on and when the target temp is reached the heating loop ball valve is turned off. Boosts take about a min or less. Having the recirculation loop and heating loop on at the same time gives quick and even grain bed temp boosts. With a 5 gal batch and insulated mash tun, about 4 to 5 temp boosts are needed for a 60 min mash. When I do my mash out I close the recirculation loop and open the heating loop and the mashout to 168 F takes about 6 mins. The expensive and complicated electronics of older RIMS systems discouraged me from building a 2 tier system for quite some time. The HERMS design allowed me to use one pump, one propane tank and regulator, and brew on a system that is efficient, simple and enjoyable to brew on . Oh yes and it makes pretty good beer IMHO..... Wayne Big Fun Brewing Milwaukee Return to table of contents
Date: Sat, 26 Sep 1998 09:32:20 -0700 (PDT) From: Domenick Venezia <demonick at zgi.com> Subject: Mash Out / Philosophical aside From: Darrell <LEAVITDG at SPLAVA.CC.PLATTSBURGH.EDU> >I have read that mash out is important (~168 degrees) so as to kill the >enzymes. But I am unable to find anywhere (I just ordered the George Fix >book) WHY? What is the reason for this, or what is harmed by NOT doing >a mash out? My problem (one of them ) is that I like to understand >why.... The traditional answer to "mashout, why?" is to kill (denature) the amylase starch converting enzymes to get repeatability and consistency. If the enzymes are not stopped then they will continue their work through out the sparge and the mash that you thought was 90 minutes was really 137 minutes - conditions that are hard to duplicate on your next batch. The more important answer (in my opinion) is that mashout raises the temperature or your mash bed, and this rise in mash bed temperature leads to easier and more efficient sparges. Also, if you have the room in your mash/lauter tun you can do mashout with all of your sparge water, let it sit, recirculate, and sparge until dry. Basicly, a single batch sparge. Not particularly efficient, but no hassles with balancing sparge water input with wort output, and you can make up for the lower efficiency with more grain. As a philosophical aside ... (is it an "aside" if it's in the subject?) The first few years that I was brewing I was very concerned (some may say obsessed) with the efficiency of the process, sparge extraction rate, overall extraction rate, and such. Eventually I came to realize that this was brewing on the edge, brewing in the boundary conditions of the process, and as such my beer was suffering. Being obsessed with efficiency made me push my temperatures to the limit, made for long sparges, large volumes, and interminable boils. This risks astringency, carmelization (not good in a pale), and makes for a very long brew day. Now I just increase my grain bill, sparge faster and cooler, collect less wort, and don't worry if my sparge is only 65% efficient. This way I can keep all the process parameters within their comfort zones, and accidental variance of a single parameter won't greatly affect the outcome. In contrast when brewing on the edge variance in a single parameter will have much more affect on the final product. Domenick Venezia demonick at zgi dot com Pursuant to US Code, Title 47, Chapter 5, Subchapter II, '227, any and all nonsolicited commercial E-mail sent to this address is subject to a download and archival fee of US$ 500. E-mailing denotes acceptance of these terms. Return to table of contents
Date: Sat, 26 Sep 1998 10:01:43 -0700 From: "Doug Otto" <dotto at calweb.com> Subject: Not again... I'd like to know if anyone has ever tried using lye with Clinitest and if so, can you use it to kill botulism spores? Sorry, just couldn't help it. - -- Doug Otto dotto at calweb.com Sacramento, CA Return to table of contents
Date: Sat, 26 Sep 1998 13:21:29 -0400 From: Jeff Renner <nerenner at umich.edu> Subject: McEwan's yeast and YeastLab IDs The recent discussion of McEwans leads me to suggest that, as with all cloning attempts, the yeast selection is critical. Yeast Culture Kit Co. (Dan McConnell prop., mailto:YCKCo at aol.com) sells the real McCoy, er, I mean, the real McEwans. I used it two years ago for an 80/ Export (OG 1042) and repitched the top cropped yeast for a 70/ Scotch ale (OG 1078). The export was too heavy with diacetyl for my taste, but it certainly was not out of style. The strong ale had none, perhaps because of the long secondary. I won't include the recipe, though, because the beer turned out disappointingly uncomplex. I shoulda used a little roasted barley, for one thing. I used only pale malt, a 5% Munich and 6% total caravienne and caramunich. YCKCo also sells almost any yeast on slant that you could want (standard disclaimer). For the last two brewing seasons, my favorite ale yeast has been the Strathcona strain, used by the now defunct Strathcona Brewery in Edmondton, I think. Jim Liddil has suggested that it is originally NCYC 1332. It is a terrific top cropper, which I love for open (although prudently loosely covered) ferments. I'd use it for the beer it produces (good fruity British style), but the heavy top flocculation makes it a real winner. Someone recently wanted to know origins of commercially avilable yeasts. Here is Dan McConnell's post from 1994 on YeastLab IDs (Dan produces liquid YeastLab yeasts for GW Kent). There is the additional A10 (available to micros and BPs only) which is NCYC 1187. This is a fine yeast whose flocculation characteristics lend it well to cylindroconical fermenters. The "W" stands for Weihenstephan, the Bavarian brewing school, which keeps a yeast collection. -=-=-=-=- Date: 14 Dec 1994 21:59:06 -0500 From: "Daniel F McConnell" <Daniel.F.McConnell at med.umich.edu> Subject: YeastLab ID's Subject: YeastLab ID's >The comments in the parenthesis are what I had heard to be the sources of >some of the strains. If anyone else would like to add/correct my assumtions >please do! In response to Rich Larsen (rlarsen at squeaky.free.org) here are the YeastLab strains. BTW these are positive ID's. No assumptions. Honest. A01 Australian Coopers A02 American Chico A03 London Whiteshield A04 British Whitbread A05 Irish Guinness A06 Dusseldorf W164 A07 Canadian Molson A08 Belgian Brigand A09 English Ringwood L31 Pilsner W34/70 L32 Bavarian W206 L33 Munich W308 L34 St Louis A/B L35 California Anchor W51 Bavarian Wheat W66 W52 Belgian Wheat Bruge M61 Dry mead Pasteur champagne M62 Sweet mead Steinberger 3200 Brettanomyces Cantillion 3220 Pediococcus Cantillion -=-=-=-=- Jeff -=-=-=-=- Jeff Renner in Ann Arbor, Michigan c/o nerenner at umich.edu "One never knows, do one?" Fats Waller, American Musician, 1904-1943. Return to table of contents
Date: Sat, 26 Sep 1998 14:43:10 -0400 From: dbgrowler at juno.com (michael w bardallis) Subject: Oats are not rye Michel Brown relates his experiences with oats, and seems to equate this to brewing with rye. Al has reported on his results using rye, which in my experience does produce the spicy flavor and heavy body he tells of. Rye-P-A is a favorite at our house; I've used both flake and malted rye in varying proportions, and the flavor and viscosity effect is quite noticeable. My first rye ale, Leap Beer, had only 13% flaked rye and had the spicy flavor I expected, with an incredibly heavy body which was pretty startling in a very pale beer. This despite a mash schedule including a 30 min rest at 122, and a max sacch. temp of 150! Oats are said to contribute to mouthfeel and add some dryness, but I haven't brewed with oats. I have, howerver, had many commercial and homebrewed beers brewed with oats, and noticed _no_ similarity to a rye beer. Rye is rye and oats is oats... Mike Bardallis Allen Park, MI (28 miles east of Jeff R.) Incidentally, it was 'Leap Beer' because: a) Wife Colleen asked, "are you sure you want to do this? What do you know about rye? b) I brewed it on Feb. 29! ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] Return to table of contents
Date: Sat, 26 Sep 1998 16:14:02 -0500 From: Louis Bonham <lkbonham at phoenix.net> Subject: Update: Masters Championship of Amateur Brewing The latest from MCAB central . . . . . (1) The last three Qualifying Events for the MCAB are coming up fast: DIXIE CUP (Houston) . . . Oct. 23-24, entries due Oct. 10. Website: www.foamrangers.com NOVEMBEERFEST (Seattle) . . . Nov. 7-8, entries due Oct. 31. Website: www.brewsbrothers.org CANADIAN MASTERS (Toronto) . . . Nov. 7, entries due Nov. 7. No website; e-mail contact is: richard.oluszak at sympatico.ca Time grows short . . . get those entries in soon! (2) I am pleased to announce that the grand prize for the MCAB BOS will be something truly special. Thanks to the fine folks at the Seibel Institute and Crosby & Baker (and one more sponsor that I'm not at liberty to ID just yet), the winner of the BOS round at the MCAB will receive a free Seibel Short Course (value: $2,400+). How 'bout that? We're currently working with other folks in the home and craft brew supply business to arrange lotsa other prizes, but suffice it to say for now that in addition to the usual medals / ribbons / doohickies, the winners in the various categories should be receiving coupons for things like sacks of malt, hops, yeast, IBU assays, brew kettles, brewery / lab chemicals and equipment, etc. [Obviously, if anyone wants to donate prizes or sponsorship funds, lemme know - -- this is a great opportunity to get your product into the hands of the very best of the amateur brewing community. Similarly, if anyone wishes to exhibit their products at the MCAB, please contact me.] (3) For those of you who have qualified, the entry packages will be mailed out soon (sorry for the delay, but I've been utterly swamped as of late), and yes, the web page will be updated soon as well. (4) We're also finalizing the logistics of the actual competition and technical conference in Houston (February 12-13, 1999). In addition to the actual competition, there will be a technical conference on Saturday morning (presently scheduled to appear: George Fix, Paul Farnsforth, Dave Miller, and we're working on others), a pub crawl on Saturday afternoon, and possibly a sensory evaluation seminar on Saturday afternoon. At present, it appears that there will be no or only nominal charges for the conference functions (things like pub crawls and food will, of course, cost you something). Be there! (5) So that we can make sure that we get a large enough space for everything (and negotiate intelligently with the various hotels and potential sponsors, etc.), if you are currently planning to attend the MCAB (or even if you think you might), please drop me an e-mail. Further, we're planning a little ad campaign for later this year which will list the names of some of the various amateur brewing notables and luminaries who will be attending, so if you e-mail me please let me know if it is OK to include your name in the ad. (6) Judging of categories 1-9 will be on Friday evening, and categories 10-18 on Saturday midday. As a result, there will be only nine judging tables running at any given time, and thus we will need only 27-36 judges per session. If you are planning to attend and would like to judge, please drop me a note. For obvious reasons, preference will be given to BJCP Master level judges -- if you meet this criteria and would like to reserve a place on specific category panels, please let me know -- we will try and guarantee you a seat on your preferred panels if you will commit to attending. (Subject to maintaining some degree of geographic diversity on the panels, such reservations will be handled on a first come, first served, basis. Again, panel reservation requests are available only to BJCP Master level judges, and obviously if you've qualified for the MCAB you can't judge in your QS.) (7) While we're still more than four months away from MCAB I, believe it or not it's time to start planning for MCAB II. There have been discussions about cutting the number of Qualifying Styles down from 18 to about 12, requiring QE's to feature Qualifying Styles as individual categories, and increasing the number of Qualifying Events to 16-20. What sayeth the collective? What categories? Nominees for QE's? Nominees for the MCAB II host? Other suggestions for changes? As always, if anyone has any questions, comments, or suggestions, please let me know. Louis K. Bonham Organizer, Masters Championship of Amateur Brewing Return to table of contents
Date: Sat, 26 Sep 1998 16:13:28 PDT From: "silent bob" <holdenmcneil at hotmail.com> Subject: potatoes and mash out In the last digest Darrell asks about the importance of a mashout, and the use of potatoes in a mash. As for the mash out question, it achieves two things, by raising the temperature, you reduce viscosity, and aid runoff. Secondly, you denature the amylase enzymes in the malt, preventing further degredation of the sugars in the mash. Eventually, if not denatured, beta amylase will reduce all starch and sugars to beta limit dextrins and fermentables, leaving you with a highly attenuable wort, and a thin final beer. As for potatoes, yes they have to be boiled to gelatinize the starch, and I would be cautious of the percentage of the mash that they comprise. Presumably, being almost pure carbohydrate, a large proportion of potatoes would be similar in effect to large amounts of rice or corn: Reduced body, higer alcohol, and little flavor contribution. Also, as I was painfully reminded today while brewing my annual pumpkin ale, pasty adjuncts wreak havoc on lautering. And, by the way, due to their high fermentability to begin with, I would employ a mash out with a potatoe containing mash :^) Adam ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com Return to table of contents
Date: Sat, 26 Sep 1998 22:01:54 -0700 From: "Michael Kowalczyk" <mikekowal at megsinet.net> Subject: Please AL, "spit the hook" Al K., please don't start testing with the "C" test - We'll be reading about the debate over the results for years. I've been brewing for 3 years now, and have never had to question if a beer is done. I've never made bottle bombs (some have been aged for years), but I have had one or two that I thought I should drink quicky because they got carboated "real fast" (my sanititization is impecable, so its wasn't that). Oh well, an excuce to drink them fast and watch my priming quantity for the next beer. There are many scientific tests I "should" do. But the fact is: 1. I don't have the time (i.e. the effort isn't worth the result). 2. They are unnecessary given normal rules of thumb. 3) I make better beer than any that I've tasted %100 of the time without them - so Why? Yes, I should do a Wort Stability test. Yes, I should do a yeast cell count. Yes, I should test that the output from my lauter tun has the minimum amount of draff ..... The fact is, this is a damn riutous hobby.. lets not mutter it with too much science. I (we) don't have the spare time and money (we're making 5or 10 gallon batched for God's sake). Dave, I'm sure your test works and works consistantly. Great. Use it and be happy with your results. I (and I'll bet most of the HBD) find it to be unnecessary. - Mike, tired of paging down, in Wrigleyville. p.s. I'd really like to hear someone reply to the guy who wants a Duvel Clone. That and yeast maintenence is why I read the HBD. Return to table of contents
Date: Sun, 27 Sep 1998 02:32:00 -0400 From: Seth Goodman <sethgoodman at 110.net> Subject: GFCI receptacle for fridge I'd hoped to be a permanent lurker on this list, but I felt this was important enough to warrant mention. In HBD #2833, Bob Haines asked about using GFCI protection for a basement fridge, and in HBD #2834 Forrest Duddles gave an excellent response, with which I agree wholeheartedly. I just wanted to add a bit of information. The NEC (National Electrical Code), which is the basis for the electrical code in most, if not all of the United States, *requires* GFCI protection for all outlets in unfinished basements, *except* for "a single receptacle supplied by a dedicated branch circuit that is located and identified for specific use by a cord-and-plug-connected appliance, such as a refrigerator or freezer" (1993 NEC, Sec 210-8(a)(4) and 210-8(a)(4) Exception #1). I assume the '96 code (the latest) is the same. It is my understanding that this exception exists because electrical devices that draw a large in-rush of current on start-up (e.g., refrigerators) can trip a GFCI if it is too long a distance from the GFCI device. Therefore, if Bob wires in a conventional outlet downstream from an existing GFCI, he might have a problem. I would suggest, for safety sake, that Bob install a GFCI outlet *at* the refrigerator, and plug the fridge *directly* into the GFCI outlet. This should keep the GFCI from popping when the compressor kicks on. The alternative, a dedicated circuit from the breaker box, is a lot more work - and although legal, still won't give you the protection you really should want. (Just ask Forrest ;-)) Disclaimer: I have no formal training or licensing in this, but the clown who rewired my house about 15-20 years ago *forced me* to study up on wiring technique and the NEC (and the Massachusetts modifications thereof). I like to do things right, and legal, if I can. Thanks for the non-beer related bandwidth - I'm going back to drinking a homebrew now! Seth Goodman sethgoodman at 110.net Return to table of contents
Date: Sun, 27 Sep 1998 00:25:29 -0400 From: "Steve Alexander" <steve-alexander at worldnet.att.net> Subject: DIabetic Meters for Wort Glucose measurement Old Man Scanlon wrote ... >As a regular user of a One Touch II blood glucose meter, I *had* to try >testing my ready-to-bottle beer (do diabetic homebrewers have their own >newsgroup?). I can confirm that it doesn't work. Doesn't matter whether or >not there's any glucose in the beer; it fails the meter's sanity checks for >sample validity. And you're out one more precious drop of homebrew. I've used this same model meter to take accurate wort and glucose solution readings so yes it does work, but there are tricks involved in making the measurement. The complicating factors are that many meter also attempt to sense good blood coverage of the sample strip by optical means. Actually the One Touch II is known to be rather light sensitive and blood readings taken in diffuse or stronger daylight are often rejected by the meter. This can be overcome for the One Touch series of meters by performing the test under very dim light. This doesn't affect the glucose reading, it only prevents the meter from rejecting the sample as invalid. The calibration liquid for the meter uses blue dye to mask this effect. A small amount of blue food coloring in the wort sample should also solve this problem. Why blue not red ?? This particular meter's strips reagent surface turns a dark purple blue when in contact with blood. My wife's Glucometer Elite uses red dye in the calibration fluid. Another problem is that meters are designed to have optimal accuracy around normal blood sugar levels of 100mg/dL (1 gram/Liter or 5.55 mMol) and fresh wort is around 8X this level very roughly of glucose. Many meters will just display an 'out of range' reading for values this high. Sample dilution is the way to resolve this problem. These diabetic meters are extremely attractive for wort measurements - they are relatively cheap (in the US) and accurate and simple to use. Tho' the 3 digit display overrepresents the accuracy available - still these meters are in my experience accurate to within ~1 mMol (+-20mg/dL) and often much better, and have much better repeatability (~0.3mMol, +- 5-7mg/dL). The big problem is that they can't easily help in the determination of the end of fermentation since glucose is the first wort sugar to be consumed by yeast. These meters could probably be of use in determining the start of fermentation. Also the removal of all glucose is nearly commensurate with the beginning of maltose consumption. It's not clear why you would want to measure these parameters unless you are serious about studying the lag phase or exponential(log) growth phase timing. I promised not to mention the 'C' word, but one way that a reducing matter test could be of HB value in determining the EOF is as follows. Perform a forced fermentation test on a wort sample and measure the reducing matter remaining. This then forms a limit value for the remaining wort. The advantage over the standard practice of measuring SG against a forced sample is that now the forced fermentation sample can be just a few tens of milliliters instead of a half liter or more. Yeast choice can impact the final reading slightly so this test shares this flaw with other forced fermentation tests. There - I didn't mention the 'C" word but I really danced around it, which is the order of the day. Now if we only had an accurate Clintontest ;^) Steve Alexander Return to table of contents
Date: Sun, 27 Sep 1998 02:09:23 -0400 From: "Steve Alexander" <steve-alexander at worldnet.att.net> Subject: re: Stability of yeast on slant Ed D'Anna writes ... >So, what happens to yeast from a slant when it gets old? What limits >its effective utility? Is it low viability? The issue is viability. The chilled yeast continue to use carbohydrates although at a very low rate. Two storage carbs trehalose, a disaccharide like maltose and glycogen, a branched polysaccharide are built up in yeast during later fermentation, that is after growth has nearly ceased but while significant sugars remain to be fermented. When other carbs are removed or unavailable the metabolism of the yeast shifts to using these internal storage carbs and reducing energy needs. I've read that this metabolic shift itself uses about 20% of the available trehalose after which glycogen becomes the main energy source. The cell continues to need energy for tasks such as protein repair, enzyme replacement, cell call and membrane repair. It of course ceases to reproduce - tho' sporulation is possible. When it's out of carbs the cell becomes unrevivable - dead. Obviously storing yeast with a good supply of storage carbs is critical. Storage of yeast in glycerin and trehalose solutions is widely reported to improve viability esp through freezing temps. >If so, wouldn't extra "stepping-up" compensate? Yes - assuming you can somehow maintain pure culture status - that's a big assumption tho'. More on this below. >Is it yeast mutation? Yeast 'mutate' at a pretty hefty clip. Oxygen deficient mutants are reported to represent 0.5% of new yeast cells !! I should point out that most of the commonly reported mutations or petite mutants are really just expressions of genetic machinery that the original yeast culture contained but did not use. Not a real genetic structure variant. Most yeast reportedly carry the codes necessary to become respiratory deficient, to decarboxylate phenolics into 4VG like a weizen yeast and to become nonflocculant just to mention a few. If the number cells that express these characteristics become significant then you have a problem. Reducing the cell population to near zero and building it back up without testing for fermentation characteristics increases the probability of a mutation problem. * Selection --- Restarting low viability cultures is also a selection process. You are selecting yeast that perhaps have a very great ability to build storage carb or have low energy requirements or other such properties. It is not unlikely that this selection will also have an impact on fermentation characteristics (flavor, growth rate etc). This potential problem would be exaggerated as you repeatedly repropagate these low viability cultures time and again. This is not a good long term plan. - * Infection/Sanitation - I'm not sure that it has been published yet, but it certainly has been publicly mentioned that Louis Bonham performed a set of infection tests on a significant sample of beers and a vast majority tested positive for infection. I sincerely hope that Louis will write up this experiment in another of his great 'Brewing Techniques' articles or elsewhere. Actually I have some reason to doubt that Louis' test method was capable of detecting wild yeast infections - the results may be worse than we know. So the next time someone tells you he has never experienced an infection you can pretty safely bet the farm that not only his last beer contains an infection but most of its predecessors too. The question for HB is really not whether it's infected, but how extensive and damaging the infections are !! Why does working with a low viability culture improve the odds of infection ? The fewer cells require more time to consume simple sugars and to lower pH and develop the several other factors that inhibit infections during step-up. Extra time means extra competition from infections, and if your sample was *ever* exposed to room air it is quite likely infected to some extent. The ultimate hubris is of course imagining that streaking out and reculturing (growing a culture from a single yeast cell) can result in a pure culture without resorting to glove boxes, HEPA filters and extreme (by HB standards) sanitation measures. - -- My personal approach for yeast storage is to use largish (~240ml) flat sided bottles - similar to the Nunc tissue culture bottles advertised by Cole-Parmer which permits a yeast surface growth of about 25 sq.cm. (4 sq.in). Even after a year these take off at roughly the speed of a Wyeast pack. I revive the culture by adding ~150ml(5 fl.oz) or freshly p-cooked and cooled wort to the bottle and stoppering with fermentation lock. The bottle size does limit my culture collection, but the maintenance effort is very low. I can't advise this method for general use - this has limitations too - but it works well for me - YMMV. Steve Alexander Return to table of contents
Date: Sun, 27 Sep 1998 05:58:36 -0400 From: "Steve Alexander" <steve-alexander at worldnet.att.net> Subject: re Osmotic Shock/Microwave There has been some stuff written recently re osmotic shock that is I think a bit confused as far as the explanation goes. First off osmotic pressure is due to a the differential concentrations of material across the cell membranes. It requires a semipermiable membrane, for example one that will pass water freely but not salt ions (for example). Assuming all the contributions are from maltose (not accurate but a decent point of departure for calculations. Then a wort at the Plato levels indicated create an osmotic pressure (in bars) and water activity indicated. Plato Os-prs A(w) 5P 3.86 0.9972 10P 8.24 0.994 15P 13.3 0.990 20P 18.9 0.986 25P 25.9 0.981 30P 34.4 0.975 I'll spare you all the tedious calculations. These sound like tremendous pressures, but single celled organisms take these and more regularly. The difficulty isn't really with the pressure gradient bursting the cell (except in the case or re-hydrating dry yeast which is another matter) but of the cell having to perform a tremendous amount of work to keep the good stuff in and the bad stuff out of its semipermiable membrane. Increasing the salt (NaCl) concentration from 0.1 mol to 1.0 mol for example causes a 10X increase in a yeast cells maintenance energy requirement ! Anyway the term osmotic shock is I think not applicable. Once the yeast begin to create permease its membrane becomes somewhat permeable to maltose and so the pressure differential drops. I doubt that yeast in the exponential growth phase (high krausen) can be shocked by the osmotic pressure difference even when tossed into barleywine wort. Yeast can experience excretion shock when introduced into a high monosaccharide wort but that's another story altogether. Several sources note that typical brewing yeast can be coaxed up to very high alcohol levels (~12%!!) by using batch feeding to increase alcohol tolerance. I suspect that *this* is the effect seen in the above schedule. Perhaps slowly increasing the ethanol level in a standard SG wort would accomplish this end without compromising growth so severely. Yes - maybe you should give your yeast a shot of vodka before sending them off to ferment barleywine. The batch feeding schedule works too - but the growth at high gravity is poor and batch feeding is known to produce fusels. Although I've advocated acclimating yeast to a wort by using comparable starter conditions, I believe that attempts to build large and healthy brewing yeast crops in the 1.070+SG wort indicated will result in disappointment as the growth and vigor of the yeast will be substandard. You probably need to build the yeast mass at a more conventional SG and then step up the SG/alcohol levels to get the desired effect. Mutation - I doubt that osmotic pressure causes mutation per se, tho' high gravity worts (high amino's, low O2) may give respiratory deficient mutants a comparative advantage. Batch feeding a starter to high SGs would make this problem worse not better. The ?good? news is that the mutant yeast, like the normal yeast won't be doing a lot of multiplying at high SG. The problem with yeast remaining after a high gravity fermentation is that they are pooped out. Perhaps they put so much energy into building alcohol tolerant membranes and moving matter against the concentration gradient that they cannot build up storage reserves - that's speculation btw. These yeast can undoubtedly be recultured, but directly repitching after a high gravity ferment is a marginal policy. - -- On a lighter note - before the microwave heating thread is entirely forgotten. Someone noted that putting ceramics with a metallic paint in the microwave makes for a nice lightening display. I've recently seen that the display when microwaving a CD is fantastic. I strongly suggest microwaving anything (and everything) by Celine Dion. Steve Alexander Return to table of contents
Date: Sun, 27 Sep 1998 12:46:50 +0100 From: "Mort O'Sullivan" <tarwater at brew-master.com> Subject: Re: Stability of yeast on slant Ed D'Anna asks about the stability of yeast on slants. Yeast will be metabolically active on slants in your fridge, and as the nutrients in the medium are exhausted, it is a good idea to transfer to fresh medium. Every six months seems to be a good rule of thumb. I've seen research that shows that as few as 10% of inoculated cells remain viable after 6 months storage on agar slopes. I'm sure you're seeing this effect with the longer lag times for older slants. Exactly how long you'd have to wait before your yeast reach 0% viability I do not know, but it probably depends on your storage conditions and the yeast strain. For your purposes, the survival rate doesn't really matter, so long as those that remain viable are typical of the original culture. NCYC monitored yeast on agar slopes over 10 year period (they were transferred to fresh medium approx. every 6 months) and found the following morphological and physiological changes: ability to form spores (loss) 46% maltose fermentation (gain) 25% maltose fermentation (loss) 0% maltose assimilation (gain) 29% galactose fermentation (gain) 12% galactose fermentation (loss) 1% galactose assimilation (gain) 12% specific A.A. requirement (loss) 59% changed flocculation characteristics 10% NCYC cares about these kinds of statistics because the success of their business depends on being able maintain stable cultures for their clients. This is why they choose to preserve yeast in liquid nitrogen (all cellular activity stops below -130C). You could probably tolerate a little genetic mutation and so don't need to worry too much about these figures. As a home brewer storing yeast for long periods, the only mutation I would keep an eye out for is a change in flocculation characteristics. Since it's not that hard to prepare fresh slants, I would also transfer my cultures about every 6 months. Hope this helps. Mort O'Sullivan Return to table of contents
Date: Sun, 27 Sep 1998 14:06:47 -0400 From: Dan Listermann <72723.1707 at compuserve.com> Subject: Malting, Rye Beer and Mashout Ed Steinkamp discusses his attempt to malt quinoa. He did not mention anything about sprouting the grains. If he did not sprout it, he did not malt it. What he may have done was gelatinize the grains by steaming them. Michel Brown discusses rye beer. I have made 100% rye beers - a porter using chocolate rye and a pale ale using only rye malt. The secret is rice hulls - about 15% of the weight of the grist should be well mixed in rice hulls. As far as flavor goes, I didn't notice any astringent flavors. The only unusal thing about rye is its body. It is almost slimy. The flavor is somewhat "earthy", but not so much as to be objectional. Darrel ( no last name ) asks about mash outs. There are two purposes for it. It denatures the enzymes so as to stableize the wort and it gives better extraction. Frankly I no longer do it. The enzymes are slowing at this point anyway, I transfer the wort as it runs into my boiling pot so it is denatured there and I have never been able to measure a exctraction difference with it or without it. I think that this is one of those things that may have a use in an industrial scale, but for homebrewers I think that it is mostly just an academic excercise. Obviously I don't think that it is worth worrying about. Dan Listermann Check out our site listermann.com Return to table of contents
Date: Sun, 27 Sep 1998 14:59:56 -0400 From: "David R. Burley" <Dave_Burley at compuserve.com> Subject: Clinitest Test Brewsters: AlK said >Dave said: >>Clinitest is nearly perfect in that it >measures all reducible sugars in beer. These are all fermentable. AlK: >Wrong. They are *NOT* all fermentable. Many (unfermentable) dextrins >have reducing ends and thus would cause a positive response on >Clinitest. This was my initial suspicion (why I initially felt the >test may be suspect) and why I still contend that some beers will >read greater than 1/4% "glucose" when they are indeed fully fermented.< Al, I daresay there are few readers of HBD who are unfamiliar with this unsupported opinion of yours. Fact is, you have your suspicions but no facts and you refuse to gather them, despite my pleadings for months. My facts stretch back over several decades and are in many pages of my notebooks. Another HBDer has written me to suggest a study be carried out by HBDers in which good brewing practices with regard to agitation, yeast starter size, temperature, oxygenation and the like and a steady reading of % glucose by Clinitest over several days to a week be used as the fermentation endpoint. I think this is a great idea, but it should be independent of either of us, except to comment on the conditions for the experiments before they are carried out. How about that? Keep on Brewin' Dave Burley Return to table of contents
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