HOMEBREW Digest #2806 Mon 24 August 1998

[Prev HBD] [Index] [Next HBD] [Back]

		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

  Diluting OG (Mark Riley)
  Thank you (Bruce Daniels)
  Salt solubility in beer (Fred Johnson)
  Mort's Magnificent Seven (Charley Burns)
  The truth about American Beers ("Robert C. Sprecher, M.D.")
  Stats ("Dr. Pivo")
  using our yeastie friends (Mark Tumarkin)
  post stats ("Dr. Pivo")
  Topping off formula ("Steve")
  dunking pretzels (as salt adjunct) ("Dr. Pivo")
  Filter ratings for air injection into wort (Dean Fikar)
  need help with wild irish rogue clone (Jonathan Edwards)
  Topping water and OG (bob farrell)
  RE: Keg Pressure (LaBorde, Ronald)
  DC area recommendations? (Paul Kensler)
  burning mold onto a bottle (Mike Allred)
  Re: Even More Yeast .. ("Steve Alexander")
  Upgrading to all-grain brewing (DGofus)
  Chimay beers (dgofus at aol.com) (DGofus)
  Gravity Adjustment ("C Perilloux")
  Hot Side Aeration ("George De Piro")
  First Brew (Timothy Skowronek)
  refractometers (DR McKeel)
  statistical significance (James_E_Pearce)
  Also Sprach Zarathustra (Jim Liddil)
  Homegrown hop plugs (MrMike656)

Let a good beer be the exclamation point at the end of your day as every sentence deserves proper punctuation... NOTE NEW HOMEBREW ADDRESS: hbd.org Send articles for __publication_only__ to post@hbd.org (Articles are published in the order they are received.) If your e-mail account is being deleted, please unsubscribe first!! To SUBSCRIBE or UNSUBSCRIBE send an e-mail message with the word "subscribe" or "unsubscribe" to request@hbd.org. **SUBSCRIBE AND UNSUBSCRIBE REQUESTS MUST BE SENT FROM THE E-MAIL **ACCOUNT YOU WISH TO HAVE SUBSCRIBED OR UNSUBSCRIBED!!! IF YOU HAVE SPAM-PROOFED your e-mail address, the autoresponder and the SUBSCRIBE/UNSUBSCRIBE commands will fail! For "Cat's Meow" information, send mail to brewery at hbd.org Homebrew Digest Information on the Web: http://hbd.org Requests for back issues will be ignored. Back issues are available via: Anonymous ftp from... ftp://hbd.org/pub/hbd/digests ftp://ftp.stanford.edu/pub/clubs/homebrew/beer AFS users can find it under... /afs/ir.stanford.edu/ftp/pub/clubs/homebrew/beer JANITORS on duty: Pat Babcock and Karl Lutzen (janitor@hbd.org)
---------------------------------------------------------------------- Date: Fri, 21 Aug 1998 23:31:36 -0700 From: Mark Riley <mriley at netcom.com> Subject: Diluting OG AJ writes: >Bruce Daniels asked for a simple method for gravity adjustment. Let's >illustrate with an example. You have 4 gallons of wort at1.052 and you >want 1.048. A quick and dirty way to get to the desired volume is to multiply the current volume by the current gravity units and divide by the desired gravity units: 4 gal * 52 / 48 = 4.33 gal So, you'd add 1/3 gal to hit your desired OG. Cheers, Mark Riley http://hbd.org/recipator Return to table of contents
Date: Sat, 22 Aug 1998 07:41:18 -0400 From: Bruce Daniels <bdaniels at Hamptons.Com> Subject: Thank you Just a Thank You to all who have E-mailed me responses on my last couple of questions. They were a hugh help! Bruce Daniels Return to table of contents
Date: Sat, 22 Aug 1998 09:18:24 -0400 From: Fred Johnson <FLJohnson at worldnet.att.net> Subject: Salt solubility in beer AJ measured conductivity of alcohol/water solutions and was able to produce a standard curve with the hopes of applying it to beer. But he was less sucessful in getting reasonable values of alcohol content on real beer. He posted: > The aliquot was > diluted to a liter and the conductivity of the dilution measured. ABV > vs. conductivity is fit quite well by a straight line (r = 0.992) which > means that we can use this technique pretty effectively for finding the > amount of alcohol dissolved in water. When it came to beer, however, > things didn't work out so well. I measured a lager with an ABV of 5.95% > using exactly the same technique as for the calibration samples. The > estimate for ABV using the calibration regression was 10.5%. > I see at least a couple of problems here.: 1. Beer has LOTS of conductingions in it compared to your pure alcohol/water solutions. Your baseline value has to be much greater than pure alcohol/water solutions. Did you correct for the conductivity of the beer before you added any salt? 2. EtOH/water solutions are probably different than denatured alcohol/water solutions in their ability to dissolve NaCl. 3. Many other things in beer probably affect NaCl solubility, in which case you would have to have a standard curve for every beer you make and you would have to assume that the only thing different between different batches is the ethanol content-- an unreasonable assumption. Anyone out there have a different opinion? - -- Fred L. Johnson Apex, North Carolina Return to table of contents
Date: Thu, 20 Aug 98 11:16 PDT From: caburns at egusd.k12.ca.us (Charley Burns) Subject: Mort's Magnificent Seven Man did my brain sweat over this one. Scientific Notation and Metric systems tossed together with Degrees Plato is NOT my strong suit. But nevertheless, here's my attempt to use Mort's Magnificent Seven. Optimum pitching rate assumption: 1,000,000 cells per milliliter (ml) of 1 degree Plato of wort. 1,000 ml = 1 litre 5 gallons = 19 litres therefore 19,000 ml = 1 each 5 gallon batch In case you haven't figured it out yet, this is the long slow way to get around to final conclusion. Those of you good in this sort of math, can hit page down and go to the next post now. 1 batch of 1 degree plato wort therefore needs 19,000,000,000 (billion) cells. Assumption 2: 1 degree plato = .004 points of specific gravity (please correct me if I'm wrong here - its memory fading quickly). So, 1 batch of 1.004 (SG) wort needs 19,000,000,000 (billion) cells of yeast. 1 batch of 1.052 Pale Ale wort needs 247,000,000,000 (billion) cells of yeast! We're getting closer now. The worst case (least dense) sample out of Mort's Magnificent Seven (See hbd#2802) provided 2.0e+9 cells per gram of yeast cake. This converts to a "normal" number of 2,000,000,000. I know, you guys that are mathematically inclinded think I'm nuts for keeping all the zeros around. Well, now that I'm getting used to it, it does seem like a lot of typing for nothing, but... ok, so now we divide cells needed by cells per gram to get total grams needed: 247/2 = 123.5 grams. Mort was kind enough to provide the divisor in his follow up post to convert this semi liquid yeast cake in grams to fluid ounces: 29.5727. so, 123.5 / 29.5727 = 4.176 ounces (of yeast slurry for 5 gallon batch). 2 primary caveats: Assumes 2,000,000,000 (2.0e+9) cells per gm of yeast slurry (low density) Assumes 93 percent viability (very high). Assuming a 50% viability, we'd need to pitch 8.34 oz of slurry. Assuming a 25% viability, we'd need to pitch about a pint of slurry. My last 5 gallon batch of brown ale (sg 1.053) I pitched with about a pint of 1056 slurry (which had been in the fridge under distilled water for a couple of months). It took a good 18 hours to get action, even at 72F (ambient). Prior to that I pitched a 2 quart starter from a smakpack of 2206 into a 1.075 Bocktoberfest (layer of yeast only about 1/8" thick at bottom of starter). It took off with a krausen within 2 hours - but took 25-26 days to ferment out. So, I think both quantity of yeast PLUS state (ie active or dormant) makes a huge difference in visible lag time and the total ferment time. More active yeast makes shorter lag time, but not necessarily a shorter ferment time. The brown finished at 1.010 in 4 days (quick total time, but long lag time). Any comments from the collective. I need to go rest my brain now. Charley (measuring ounces but not counting cells any more) in N. Cal Return to table of contents
Date: Sat, 22 Aug 1998 10:34:37 -0400 From: "Robert C. Sprecher, M.D." <rcs8 at en.com> Subject: The truth about American Beers Actual quote from a patient's medical chart: "The catheter was draining urine the color of American beer" 'nuf said. - -- Robert C. Sprecher, M.D. Pediatric Otolaryngology Rainbow Babies and Childrens Hospital Case Western Reserve University Cleveland, Ohio Return to table of contents
Date: Sat, 22 Aug 1998 16:36:19 +0100 From: "Dr. Pivo" <irv at wireworks.se> Subject: Stats Statistics are tricky things. Beautiful in their cleanliness. Ugly in the way they can be manipulated or missinterpreted. I believe Mark Twain wrote something like "There are three kinds of lies: white, innocent lies, black insidious lies, and then there are STATISTICS!" Just saw this and thought it should be cleared up: Jim Liddil wrote: > Dr Pivo wrote: > > >The good news is that there is "almost" a statistical significant > > Sorry but there is no almost about stat. sig. Either it is or it is not. > You perform a t-test (provided you have enough data points) and at a p-value > < 0.05 either it is or it is not. It's like sterile. Nope. It's like "sanitised". One generally chooses an arbitrary "confidence" level to say "OK, looks pretty good". 95% is pretty common. 1% is better. Neither of these is "the truth" (as in sterility, which is a pre-defined term suggesting an absolute condition). OK. I'll do one of my "everyday science" things (and try and spell potatoe correctly), and let a statistician jump in and correct any missinterpretations. When you are comparing stuff that can only have two possible outcomes (like "heads and tails" on a coin), and you want to figure out if the coin is "weighted", so one side turns up more often, there's a pretty good way to test that (flip it over and over and over again, and write down your results). When you statistically test your results, you are simply saying "what are the "odds" that any difference that has occurred, happened because it is "true", or looking at the .O5 or .01 number, what are the "odds" that there is no real difference, and this occured by chance. It's not truth, Jim. At a .05 level, with your definition, you are proving that it is impossible to be dealt "four of a kind". It won't happen 5 times out of a hundred, but it will happen (just never to me, darn it.) If I was going to express myself correctly in "scienterrificese", I should have said. " testing showed a difference with a confidence level of 85%" In other words, If you were just "flipping a coin" (and there was no real difference), you would have gotten that result about 15% of the time, and that is generally not a level that we feel terribly "confident" about (sorry to mix terms... I did think it was cute). To repeat my statement in more accepted terms of the lithurgy. "Testing between cooled and non cooled batches showed a statistical significance of 0.15. This seems to indicate a need for more clearly restricting the variables and confounders mentioned (I haven't jumped on P O2 at fermentations inception, loss of hop aromatics, etc. here, but in a "big guy" paper those should be pointed out), and repeating with a larger sample size, to more clearly illuminate the existance of possible perceivable taste effects induced by rapid versus slow cooling." Now isn't that bloody boring to hear? Hardly even had any commas, hyphens, bunch of dots in a row, or any other fun stuff! Think I'll stick to "almost significant". I think most folks understand that, and if people are already confusing a .05 level of significance with an absolute condition (THE TRUTH), it's well worth avoiding those terms. Dr. Pivo Return to table of contents
Date: Sat, 22 Aug 1998 10:46:22 -0400 From: Mark Tumarkin <mark_t at ix.netcom.com> Subject: using our yeastie friends Jim: Thanks for the great post "Even More Yeast" in HBD 2805. You pointed out some things that really set my mental yeasties to fermenting. Let me preface this by saying that I am severely math and science challanged. I enjoy trying to understand some of the posts by AJ, Steve, and some of our more scientific posters, but a lot of it goes way over my head and understanding. If brewing can be approached as an art or a science (preferably an inspired combo of the two), I am clearly on the art end of the spectrum. I suspect this also describes a lot of other HBD'rs. However, it is clear to me as an artist or craftsman that the more I can understand about using my tools (including the science side), the better art (beer) I can produce. So I rarely make use of the page down key, rather I try to pick up a piece of the puzzle or two out of posts that generally go over my head. The bottom line being that I want to learn as much as possible about "best practices" and apply that as best I can to my particular brewing system and practices. You said in your post - "The other day I posted a bunch of numbers from books. Now this is all fine and good and such. But for me I would prefer to do things a little differently for the beer I make and my view of the world. When I make wort I would prefer to use it to make beer ratter than grow yeast. I prefer to grow the majority of my yeast separately. When yeast is put into wort it can either ferment and make ethanol or it can grow and make more yeast. Certainly both occur at the same time but one or the other can be favor given certain conditions. In this discussion I am talking about a normal brewery fermentation with a 12 Plato wort and yeast cells that are 95+% viable by methylene blue staining. One can choose to pitch any amount one chooses. Also one can choose to oxygenate the beer at a given level to effect the amount of yeast growth." This really caught my attention and made me think about the yeast and starters in a different light. Much as I love our yeastie buddies, I would much rather make beer than grow yeast. Obviously, we have to do both, and "brewers make wort, yeast make beer." Anyway, I'd like to ask you to clarify or expand some of your points - keeping the practical applications in mind. "Now let's consider the two situations we as brewers deal with (1) is yeast that comes from propagation under highly aerobic and nutritionally adequate conditions and (2) re pitching yeast that has been previously used to ferment a beer." You discuss doing starters using stir plates or shakers, I'd love to try that but don't have the equipment (probably most of us don't). I'm really more curious about #2. I quess most the stepped-up starters I do fall into this catagory. And if I understand your post, these would have insufficient oxygen and consequently low lipid levels. I had posted before about pitching onto the yeast cake from a previous batch. This has worked well for me. I oxygenate by putting the carboy in a plastic milk crate, tipping it on one edge, and rocking vigorously. I have an oxygen tank and air stone on my wish list, but haven't bought them yet. Do you think this procedure is adequate, or how can I improve it? With the ultimate aim of making better beer, what would be the "best practice" for oxygenating the wort in this situation? "So this is what I am trying to do in my own brewing practice. If you prefer to grow yeast, that is fine with me. If you don't worry about off flavors or slow fermentations then by all means you can ignore all of this. And of course I am sure there are plenty of people out there who end up with great beer using little to no starter. This merely some ramblings." I do worry about off flavors and slow fermentations, so if you could "ramble" a bit more about how we can apply these ideas I'd be really interested. TIA, Mark Tumarkin Gainesville, FL Return to table of contents
Date: Sat, 22 Aug 1998 17:25:43 +0100 From: "Dr. Pivo" <irv at wireworks.se> Subject: post stats While I am on the subject of Jim Liddil, since I post here so seldom, I might mention that I was very impressed with the information he gleaned from the Big Boy Brewing School (I gathered it was some such, I honestly don't know what a "Seible" is... guess we pray to different gods.), but mostly impressed by how he was able to sift through that information to find what might be relevant to a home brewer. Showed an unusual sense of perspective, and his conclusions, though "couched" in quite polite terms, were very refreshing thought I. "How convenient", I thought, as he mentioned (among other choice tidbits) that even the Big American Breweries put HSA way down on their list of oxidative worries (Remember this is the same industry whose collective motto is: "Guaranteed to not leave a taste memory"), after I felt I've been shouting that down a long dark tunnel for a couple of years, and at the very moment of reading it was sitting over a cellar filled with my attempts to finally find out at what threshold this boogie-man actually appears. Thanks, Jim Dr. Pivo Return to table of contents
Date: Sat, 22 Aug 1998 11:26:19 -0400 From: "Steve" <stjones1 at worldnet.att.net> Subject: Topping off formula Bruce asked about a formula for adjusting SG. While AJ's answer is no doubt very precise, I think this is much simpler and accurate enough for most brewers. Take the starting gravity (drop the 1 dot) and multiply times the original volume to get total 'gravity points'. Divide this by the desired gravity (again, drop the 1 dot) and subtract the original volume from this result. Finally, multiply by 4 to find the number of quarts of topping water to add. Using AJ's example: You have 4 gallons at 1.052 and you want 1.048. 4 gal * 52 pts/gal = 208 pts 208 pts / 48 pts/gal = 4.33 gal 4.33gal - 4 gal = .33 gal .33 gal * 4 qts/gal = 1.32 qts. While 1.32 qts isn't exactly 1.32 liters, it is close enough for me. Hoppy Brewing! Steve State of Franklin Homebrewers http://home.att.net/~stjones1 Return to table of contents
Date: Sat, 22 Aug 1998 17:37:51 +0100 From: "Dr. Pivo" <irv at wireworks.se> Subject: dunking pretzels (as salt adjunct) Please excuse it if this idea has already come up, usually scim AJ deLange's stuff, and haven't followed the whole thread. He was suggesting NaCl's high solubility in water and low in alcohol, as a possible "quicky" way of measuring alc content. Wouldn't electro-resistivity, as a function of dissolved ions, pre and post dumping the salt in, be a way to pluck that number out (should be irrespective of sample size or ammount of "dumped salt", once over saturation) Sorry if this thought has already been posted--- just having mind wanderings. Dr.Pivo Return to table of contents
Date: Sat, 22 Aug 1998 11:19:38 -0500 From: Dean Fikar <dfikar at flash.net> Subject: Filter ratings for air injection into wort I've recently acquired an aquarium pump and SS airstone for continuously aerating my yeast starters. I was in the process of locating an air filter when I came across a one micron filter that would be easy to splice between the pump and the wort. The device is designed to filter CO2 which is injected directly into human arteries ("CO2 angiography"). Is a one micron rating good enough? Seems like I've read that the filters specifically designed for brewing purposes are in the submicron range. I would think that if it's good enough for filtering gases into the human body then it should be okay for filtering room air going into a yeast starter. Any thoughts? Return to table of contents
Date: Sat, 22 Aug 1998 14:37:38 -0400 From: Jonathan Edwards <jdedward at us.ibm.com> Subject: need help with wild irish rogue clone hey now, i'm getting ready to do a wild irish rogue oatmeal stout clone. it's one of the best oatmeal stouts i've had even if it isn't true to "aha style". here's my recipe for 6 gallons all grain assuming 70% efficiency: 6lb Western 2-row 6lb Klages 2-row 1lb Crystal 135L .75lb Roasted barley .50lb Chocolate 1.5lbs flaked oats 3.75oz Cascade 5.7% 60 minute whole leaf 1.0oz Cascade 5.7% 5 minute pacman yeast cultured from bottle og 1.066 ibu 59 according to rogue's web page, i think this is pretty close. not sure about the dark malts. any ideas on those? i'm never sure what to use in my oatmeal stouts. i don't want an excessive roasted burnt taste. thanks, jonathan Return to table of contents
Date: Sat, 22 Aug 1998 11:57:57 -0700 From: bob farrell <bfarrell at windermere.com> Subject: Topping water and OG Bruce Daniels requested a rough formula for topping off wort in the primary to get the desired OG. I suggest: Example- OG 1050 with 4 1/2 gallons = 50 x 4.5 = 225 gravity units. If the target gravity is 1045, simply divide 225 by 45 = 5 gallons total. Just add 1/2 gallon. Bob Farrell Portland, OR Return to table of contents
Date: Sat, 22 Aug 1998 14:03:18 -0500 From: rlabor at lsumc.edu (LaBorde, Ronald) Subject: RE: Keg Pressure From: "Wilson, Todd (MCI)" <Todd.W.Wilson at mci.com> >I have 3 kegs hanging off of a 3 way manifold in my fridge. If the pressure >on my co2 is set to 15psi am I getting 15psi to each keg or am I getting >5psi to each keg? 15 Ron Ronald La Borde - Metairie, Louisiana - rlabor at lsumc.edu Return to table of contents
Date: Sat, 22 Aug 1998 23:20:47 GMT From: paul.kensler at ibm.net (Paul Kensler) Subject: DC area recommendations? I will be travelling to the Washington DC (Northern VA) area soon, and need some recommendations on "can't miss" local breweries or brewpubs, and recommendations on what locally available beers I should try. Please respond by email - paul.kensler at ibm.net Thanks! Paul Kensler Just finished brewing a stout, in Plano, TX. Return to table of contents
Date: Sat, 22 Aug 1998 21:34:05 -0600 From: Mike Allred <mballred at xmission.com> Subject: burning mold onto a bottle John A. MacLaughlin said >Rod and Mike Allred also comment on baking bottles to remove mold. >A strong chlorine bleach solution (one ounce per gallon) will cause >mold to separate from a smooth glass surface in a day or two (or >maybe three to five). Then you can just pour it down the drain, >after shaking vigorously to get it through the bottle's neck. ....Then bake them. I did not say to bake bottles to remove mold. This would make a stinking mess. I clean them first (like John's method), then I bake them. I don't know if mold spores can live after the chlorine soak, but I sleep better at night...anyway I know almost everyone in hbd disagrees with us bottle bakers, but the point of my original post was to say that 'IF you are going to bake, make sure that the bottles are clean first'. Return to table of contents
Date: Sun, 23 Aug 1998 06:57:34 -0400 From: "Steve Alexander" <steve-alexander at worldnet.att.net> Subject: Re: Even More Yeast .. Jim Liddil writes ... >Steve Alexander wrote: >>For example it's been stated that 3X is >>the yeast growth rate in ale breweries; perhaps this is so ( I still have >>doubts) , but was the purpose to perform quicker fermentations, or to >>avoid yeast growth byproducts ? If the latter why aren't they pitching a >>full >>complement of yeast and shooting for near zero growth (because it would >>cause zero fermentation right ;^) ) ? >Let me start with this: > >"In sharp contrast to the long-held belief in brewing that the bulk of wort >attenuation is done by nongrowing cells, it is now clear that the specific ... >"The rate of fermentation will depend on the rate and extent of yeast growth" >Remember this? :-) Yeast biomass growth is one major energetic requirement for yeast. I not only have stated this recently (Jim chooses to quote selectively here) but have also posted the constants associated with the energetics required some time ago. That there is a relationship between growth, energy required and fermentation rate - there is no doubt. Without context (as I said before) it is impossible to impute much meaning to the "principle" stated. What is clear is that under stationary conditions, the rate of fermentation is directly related to the yeast biomass in a proportional fashion. The Seibel statement as quoted (and I have pointed this out before too) does not define the "depend"ency in any way. The reason that Jim cites - that much energy goes into growth - *may* be the reason Seibel intended, but it still doesn't define a clear relation since yeast, even without growth do require energy (so ferment) for reasons such as creation of storage carbohydrates and some lipids (yes - even without O2 and growth). This is something like the difference between stating that the GDP depends on the total goods produced (a definition) and stating that the GDP depends on the work ethic of the populous (possible, tenable, but without detail almost meaningless). Jim states ... > When yeast is put into wort it >can either ferment and make ethanol or it can grow and make more yeast. >Certainly both occur at the same time but one or the other can be favor >given certain conditions. NO - There is a fundamental error in thinking on Jim's part here. Yeast don't *either* grow or ferment - it isn't one or the other - it's one(ferment) or both. They ferment in order to have energy in order to carry out all sorts of biological activity. If possible they reproduce, if not they still can build saturated fats, storage carbohydrates, trehalose and glycogen, and also require energy for normal biological functioning. It takes considerable energy just to keep the internal salt ion gradients in balance. This error I think taints the remainder of Jims post - it needs a revision because it does contain some important ideas. [ description of pitching high and low sterol yeast omitted ...] >So this is what I am trying to do in my own brewing practice. If you >prefer to grow yeast, that is fine with me. If you don't worry about off >flavors or slow fermentations then by all means you can ignore all of this. Frankly, despite the misunderstanding about yeast energetics I think that Jim is saying something very important here. So important that I asked the questions myself on HBD a few weeks back. What is the desired state of yeast at pitching with respect to O2 dependent lipids and storage carbohydrates ? What are the reasons for choosing higher versus lower growth factors ? For example do the byproducts really have substantially lower contributions when the new crop is 66% (3X growth) versus 83%(6X growth) ? What are the flavor consequences of higher versus lower pitching rates - and so what rate is optimal for flavor.? Jim says that he prefers to *not* have yeast growth - but one of his reasons (fast fermentation) defies his own quote about 33X slower attenuation. The off-flavors issue I find much more believable, but still there are reports in the lit of poor flavor under conditions of extremely high pitching levels too. I think that the 1% versus .125% sterol levels are perhaps taken too literally as limits and I suspect that there is considerably more variation in practice than this but I do think that lipid and particularly sterol levels may be a factor in poor fermentation such as the BT article Jim cites with 2 qt starter into 26 qt of 16.5P wort and resulting stuck fermentation. I think that balancing the O2 dependent lipids in and available to yeast is a factor worthy of consideration and the sort of control that Jim suggests. I just don't think that all the i's are dotted and t's crossed in methodology yet. Without understanding the "off flavors" created by underpitching and growth in detail we never will get to the bottom of this. I'm not sure if this was in a previous post of a private comm, but one term in models for fusel production is yeast growth rate related *but* the coefficient on the term is also dependent on the specific related amino acid - so that at higher amino acid levels the fusel production is also moderated (and from some research even stops). If this fusel term is the issue for reducing yeast growth in order to prevent off flavors (and I'm not sure this is the only factor) then adding a bit of valine, leucine and isoleucine amino acids to the wort might be a preferable solution to inducing slow fermentation and low growth - at least on HB scale operations. I'm not stating that this is the case - just stating that without understanding the nature of the problem that rushing to solutions is premature. Steve Alexander Return to table of contents
Date: Sun, 23 Aug 1998 08:24:34 EDT From: DGofus at aol.com Subject: Upgrading to all-grain brewing I need the collectives help. I am interested in going all-grain brewing but I need some help. I am happy as an extract/partial mash brewer, but think that i can do better! What equipment do I need, or would you reccomend? here is a list that i came up with from my readings. 1. Mash tun 2 lauter tun 3. ability to boil a full 5 gall. batch Any help would be greatly appreciated. Private e-mail ok Bob Fesmire Madman Brewery (soon to get Madder) Pottstown, PA Dgofus at aol.com Return to table of contents
Date: Sun, 23 Aug 1998 08:32:49 EDT From: DGofus at aol.com Subject: Chimay beers (dgofus at aol.com) I recently purchased a case of Chimay Grand Reserve (blue). Can anybody fill me in on this brew and the other offerings from this brewery. The beer is great...one problem, the first beer that I opened gave an extreme amount of head to the beer. It took a long time to get the head down enough to continue to pour the beer. It seemed like an " infected " beer. My friend, who I bought a case for, also said the same thing about his first beer. He now says that after two more bottles, everything is fine. Did I over handle or shake the beer too much during the ride home, or pouring? What is going on. I have not yet tried another bottle. At $75 a case, I am trying to preserve them! Bob Fesmire Madman Brewery Pottstown, PA Dgofus at aol.com Return to table of contents
Date: Sun, 23 Aug 1998 23:18:47 +1000 From: "C Perilloux" <peril at bigpond.com> Subject: Gravity Adjustment >Bruce Daniels asked for a simple method for gravity adjustment. Let's >illustrate with an example. You have 4 gallons of wort at1.052 and you >want 1.048. >...Subtract 1 from the specific gravity, multiply by 1000 and divide by 4. >(1.052 -1)/1000/4 = 13P. This means that 100 grams of your wort... etc. >...(1000/1.052) = 950.57. Thus 0.9507L of wort contains... etc >...10 times the Plato value by the SG: 120*1.048 = 125.76 grams... etc. >...need a total of 2067.81/125.76 = 16.44 liters to hit a gravity of... >... etc. >...You had 15.12L so you should add 1.32 liters more. My God, AJ!! I have to give it to you, it's detailed and accurate, but when the poor guy sitting there at the end of long brew session is confronted with all the arithmetic, he must think there's an easier way, even at the price of some accuracy. If the current and desired SG's are relatively close (i.e. don't do this to dilute 1.100 down to 1.040!), here's a quick and dirty: Current SG 1.052 for 4 gallons Desired SG 1.048 x = (52/48 - 1) *4 gal x = 0.33 gal This comes out to 1.26 liters. Close enough, considering that most fermenters aren't marked precisely enough to worry about 0.06 liters worth of error, not to mention that the SG reading you make with a typical homebrew hydrometer is only within a point or two anyway. Calvin Perilloux Turrella, Australia Return to table of contents
Date: Sun, 23 Aug 98 11:13:38 PDT From: "George De Piro" <gdepiro at fcc.net> Subject: Hot Side Aeration Hi all, Dr. Pivo did a nice little experiment to demonstrate that HSA is not the big deal some people believe it is. He also instructs me to pose in a silly manner. Most illogical. Anyway, I believe Rob Gump and I wrote in one of our "live from Siebel" posts that we learned HSA isn't the horrific monster some believe. It is damaging to beer, but not nearly as damaging as some of the other things we do to it. The "short George list of common beer destroyers" is something like (from worst to least worst): 1. Shoddy sanitation practices. No need to expound on this. 2. Underpitching and other abuse of yeast. This causes such a broad array of problems that it is truly staggering. I have said much about this, and will say more, mark my words... 3. Aeration of the fermented beer: incredibly damaging, even to homebrewers. An easy experiment: aerate one bottle of beer, cap it, wait a few days. Taste it blind against a bottle from the same batch that is unabused. You need not waste precious homebrew on this. 4. Cloudy lauter runoff. Don't skimp on the time it takes to achieve clear runoff! 5. Hot side aeration. The damage this can cause may be more subtle than Dr. Pivo was hoping to find, especially during the beer's youth. One thing that can happen is the lack of maltiness. The beer won't taste off, but it will be flat in its malt character. I agree with Dr. Pivo that with the myriad other things small brewers can do to their beer HSA is near the bottom of things to take care of. That doesn't mean you should go out of your way to aerate the hot wort, though! Just don't take the elimination of HSA too far (working with SCUBA gear in a nitrogen atmosphere, etc.). There are better places to spend your energy. Another caveat about experiments like Dr. Pivo has presented: who were the tasters? Are they trained tasters? What about the amount of HSA in the control batch? Maybe there is some HSA going on in both beers? I'm not trying to belittle what Dr. Pivo did (in fact, I think it's *great*), but keep this stuff in mind when reading anybody's work. Have fun! George de Piro (Nyack, NY; just home from 3 days of eating Herrell's ice cream. If you don't know it, you don't know what greatness is.) Return to table of contents
Date: Sun, 23 Aug 1998 12:10:09 -0500 From: Timothy Skowronek <cosmo at indy.net> Subject: First Brew I just compleated my first batch of beer, using a recipe for an Oktoberfest form Papazian, slightly modified for my conditions. It's not what I expected and would like some feedback. The recipe: 6.6 # Irez Amber extract !# amber dry 1/2 # carmel malt !/8 # roasted barley 1/.8# toasted barley 3 oz fresh Hallertauer (boiling) 1/2 oz plug Saaz (flavor) 1/2 pellet Saaz (aroma) I brewed on 8/1, steeping the grain and adding 2 gal wort to 3 cold water, pitch the yeast (Wyeast british Ale II, because I have no basement and could not keep the batch below 65 F) . I started the yeast a day or two earlier before pitching. The temp was kept at 68 F the whole time and my OG was 1.044.On the morning of 8/4, I transfered to a carboy and the SG was 1.026. after two days, the SG never dropped below 1.022. Was it stuck? I thought the combo of cold water and some shaking of the wort after adding to the cold water would give it enought O2. I waited till 8/10 and bottled. It is now 8/23 and I just popped one. It is like drinking malt extract. I exaggerate a bit - it seems similar in initial flaver to Sam Adams Double Bock, but really cloying in the aftertase. I think that the fermentation stopped too early. Does anyone know why this happened? Is it possible to salvage it even after I bottled? I'm just happy that the things I was most worried about (sanitation, infection, no caronation) posed no problem at all. Any help or suggestions would be appreiated. Thanx, Cosmo Return to table of contents
Date: Sun, 23 Aug 1998 20:12:39 -0400 From: DR McKeel <drmckeel at twave.net> Subject: refractometers Greetings fellow brewers, Recently I had considered the puchase of a refractometer. However, when I began looking into doing so I found that the price and features can vary cosiderably. Among the different features was automatic temperature compensation and various scales. If any of you that have any experience with refractometers would be willing to share your thoughts with me in order to help me to make an educated selection, I would greatly appreciate it. Dwayne (I've never met a beer that I didn't want to brew) McKeel drmckeel at twave.net Musty Olde Cellar Homebrewery Return to table of contents
Date: Mon, 24 Aug 1998 11:04:46 +1000 From: James_E_Pearce at nag.national.com.au Subject: statistical significance From: James E Pearce at NAG on 24/08/98 11:04 AM Jim Liddel writes: >Sorry but there is no almost about stat. sig. Either it is or it is not. >You perform a t-test (provided you have enough data points) and at a p-value >< 0.05 either it is or it is not. It's like sterile. Oh and I like to >send my bottles out for gamma irradiation so they are sterile and I don't >have to worry about heating up the house with the pressure cooker or oven. Sorry, but I'm with Dr Pivo here. There is no good reason to choose a p-value of 0.05 over 0.051 (for example); indeed, if there are a reasonable number of data points there is no 'statistically significant' difference between the T values that give p-values 0.05 and 0.051. Dr Pivo said that he needed more data points to chekc this out, that is exactly right. A p-value of 0.05 means that you are concluding there is a difference when there is none 1 time in 20. Cheers James in Melbourne Return to table of contents
Date: Sun, 23 Aug 1998 18:52:21 -0700 From: Jim Liddil <jliddil at azcc.arizona.edu> Subject: Also Sprach Zarathustra This simple my take on the BT vol 6 no1 article. It has been my experience and that of others that one can get about 2 X 10e8 cells /ml in a starter using a stir plate etc. This seems to be a maximum and typically I get about 1 X e-8 for the ~1045 starters I have tested lately. Let's look at the BT article in vol 6 no.1 that compared decoction and RIMS beers and experienced a stuck fermentation with the 16.5 P bock. The text indicates that the wort was pitched with a 2 quart starter. 2 quarts is equal to 1.89 liters. All the text says is that the starter was made using a step up procedure and does not indicate if the starter was continuously agitated or not. It is then likely the yeast had a low sterol and UFA level when the went into this high sugar environment. I am going to make the leap of faith and guess the starter had 1 Xe8 cells/ml at the time it was pitched into the beer. Simple math indicates that the starter would have had 1.89e11 cells total (1.89 Liters X 1e8 cells/ml). This was pitched into a volume of 6.5 gallons. the total volume then is 6.5 gallons (24.6 L) + 1.89 L = 26.49 L. If we do the math again this gives us a figure of 7 X10e6 cells/ml in the wort at the start. This is the minimum level one would use for a normal gravity beer in the range of 11 Plato. The beer that stuck was 16.5 P. A minimum number of cells for a beer of this gravity would be ~17 million cells/ml and a more typical number is on the order of 20 million cells/ml. So I feel the authors started off by under pitching. The wort itself was aerated using air via a fish pump and then inoculated with the starter or so the text seems to indicate. This is another point where the authors and other brewers can do things to prevent stuck fermentation. The rule or thumb that I have read and heard about is that one should increase the oxygen level 1 ppm for each degree Plato above 10 P. If air saturation gives 8 ppm then a 16.5 P wort should be oxygenated to a level of ~15 ppm oxygen. The authors used air so the best they could get was 8 ppm. Also wort of this gravity has a lower oxygen solubility (someone can probably tell us what the conc. was approx) presenting another disadvantage for the yeast. For those using air a simply aeration and then pitching is not enough for this gravity of beer. One needs to aerate for a longer period of time so the yeast can get enough oxygen to synthesize a maximum level of sterols and unsaturated fatty acids (UFAs). These yeast are going to have to deal with fermenting a larger amount of sugar and withstanding stress from higher ethanol levels. Only if one were to pitch a very large amount of yeast that already had maximum levels of sterols and UFAs would simply aeration be enough. The authors took gravity readings at 6 weeks and low and behold the beers had not fermented out. hmmm. And the authors state "although significant amounts of viable yeast were present....." My question is how did the authors determine the yeast were viable? I would presume methylene blue was used. Methylene blue staining really tells one nothing about the actual state of the cells other than that they can exclude the dye. In Brewing Science volume 2 it is stated that MB works well for healthy cultures but gives highly erroneous results with cultures in poor condition. A table is presented showing that cells heated at 43 C may show 97% viability by MB but when tested by plate or slide culture show less than 1% viability after 3 minutes of heating. The authors decided to pitch more yeast in the amount of "One quarter of the cultured yeast slurry was added to the RIMS and Infusion mashes and one half added to the decoction mash." The RIMS and infusion beer reached terminal gravity "fairly quickly". Not sure what that is but compared to 8 weeks anything is quick. The decoction beer still edged along. I presume the authors knew the two beers and reached true terminal gravity either via a forced test or Clinitest. Why did the one beer not finish? It is hard to draw any concrete conclusions based on the limited N value. But adding new yeast that may not be at full sterol and UFA level to an environment of no oxygen, low nutrient levels, some alcohol is a problem any one who repitches faces. Also at the point in time the authors repitched the glucose may have all been depleted along with some maltose. The yeast may have been to stressed by all this. This is by no means a definitive diagnosis since the other two beers finished "fairly quickly".. In general it looks like the decoction mashing did something to the wort sugar profile and nutrient profile that lead to this slow fermentation, but who knows. My point (and I don't mean to pick on Louis and the others) is that here we have one guy who has a SABCO unit that was till expensive when Louis go it a few years ago. Andy Thomas went to all the trouble to do a triple decoction. These guys put all this time, money and effort into making these beers and even wrote an article about it. It is my belief that they and many other could save themselves a lot of grief by directing some of their money and efforts toward making bigger starters. And I am sure many people are going to chime in "I made a 1070 beer and it fermented out in a week ....." Then again we have Charley who wrote: "2 quart starter from a smakpack of 2206 into a 1.075 Bocktoberfest (layer of yeast only about 1/8" thick at bottom of starter). It took off with a krausen within 2 hours - but took 25-26 days to ferment out." I am sure others can point out things I may ahve missed, since this is a quick take on things. And the Megas make 16 P (high gravity brewing) many times a day that ferments in a few days, and you can do it too. Not that you might want to exactly follow the time temp process they use. The point being that even a high adjunct low FAN high gravity wort can be fermented quickly provided one use proper oxygen and yeast levels. But again even though this may read like I am being dogmatic I do not mean it to be. Please feel free to do as you wish and what works for you. Jim Return to table of contents
Date: Sun, 23 Aug 1998 22:24:11 EDT From: MrMike656 at aol.com Subject: Homegrown hop plugs I thought I'd pass this trick along - My wife complained that my hop crop was taking up too much space in the freezer. So, I thought, why not make plugs? I had a cigar mold lying around, so I took my freshly picked and dried hops and stuffed them into the mold, and tamped them down with a 3/4 in. dowel. After a few hours, the oils bind the hops together, and I have several Churchill sized hop cigars. Easy to store and much easier to weigh than loose cones. If you haven't got a cigar mold around, you could probably use a piece of PVC pipe as a mold. Mike Maimone Return to table of contents
[Prev HBD] [Index] [Next HBD] [Back]
HTML-ized on 08/24/98, by HBD2HTML version 1.2 by K.F.L.
webmaster at hbd.org, KFL, 10/9/96