HOMEBREW Digest #4324 Sat 16 August 2003

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  Dr. Cone/ Tobias Fischborn Responds - Fredrik-Part 2 ("Rob Moline")
  Dr. Cone/ Tobias Fischborn Responds - Fredrik-Part 3 ("Rob Moline")
  Rob Moline 2003.  Dry yeast varieties ("Rob Moline")
  Dr. Cone, 2003 - Lager Pitching Temperature (David Lamotte)
  Dr. Cone, 2003 (Eric)
  RE: Aerobic Yeast Propogation (Michael Hartsock)
  RE: Exploding CO2 Tanks, Really? (Michael Hartsock)
  Brain aneurysms and beer ("Dan Listermann")
  Chad's Father-in-Law (rickdude02)
  Re: Beer in NorCal/Sonoma ("Richard S. Sloan")
  Re: Double the Recipe? (MOREY Dan)
  Mash Step Time  and Mash pH ("Martin Brungard")
  Re: Aerobic yeast propagation ("Martin Brungard")
  Dr. Cone, 2003-barley wine-Harlan Nilsen ("Rob Moline")
  Increased Utilization with Larger Batches (MOREY Dan)
  Room enough for 10 gallons? ("Jennifer/Nathan Hall")
  Dr. Cone, 2003- bobz ("Rob Moline")
  Dr. Cone 2003, Training Yeast (Alexandre Enkerli)
  Dr. Cone 2003, Organic and Engineered Yeast (Alexandre Enkerli)
  Dr.Cone Responds-Jurriaan Boekamp ("Rob Moline")
  Dr. Cone Responds- Ken Schramm - Mead query ("Rob Moline")
  Dr. Cone Responds-wort oxygenation-Bob Devine ("Rob Moline")

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * The HBD Logo Store is now open! * * http://www.hbd.org/store.html * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Beer is our obsession and we're late for therapy! * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * COMING TO THE HBD! * * * * * * * * * Dr. Clayton Cone Fortnight of Yeast * * 8/11/03 - 8/22/03 Yeast Questions Answered * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Send articles for __publication_only__ to post@hbd.org If your e-mail account is being deleted, please unsubscribe first!! To SUBSCRIBE or UNSUBSCRIBE send an e-mail message with the word "subscribe" or "unsubscribe" to request@hbd.org FROM THE E-MAIL ACCOUNT YOU WISH TO HAVE SUBSCRIBED OR UNSUBSCRIBED!!!** IF YOU HAVE SPAM-PROOFED your e-mail address, you cannot subscribe to the digest as we cannot reach you. We will not correct your address for the automation - that's your job. HAVING TROUBLE posting, subscribing or unsusubscribing? See the HBD FAQ at http://hbd.org. The HBD is a copyrighted document. The compilation is copyright HBD.ORG. Individual postings are copyright by their authors. ASK before reproducing and you'll rarely have trouble. Digest content cannot be reproduced by any means for sale or profit. More information is available by sending the word "info" to req at hbd.org or read the HBD FAQ at http://hbd.org. JANITOR on duty: Pat Babcock (janitor@hbd.org)
---------------------------------------------------------------------- Date: Wed, 13 Aug 2003 22:49:38 -0500 From: "Rob Moline" <jethrogump at mchsi.com> Subject: Dr. Cone/ Tobias Fischborn Responds - Fredrik-Part 2 Dr. Cone/ Tobias Fischborn Responds - Fredrik-Part 2 Also I've got a nutrition uptake related question 5) I've read that the uptake of nutritions, or at least FAN are restriced to the lag phase that are put into pools used throughout the fermentation. And that nutrutions that are added in the middle of fermentation is not utilized. Is this true, and why? Are the transporters blocked or busy? Are there special purpose transporters for amino acid uptake that are never used for sugars? Clayton: Transports systems for amino acids are entirely different than for sugar uptake and alcohol output. Very little if any FAN is taken up by the yeast during the lag phase. The majority of the FAN is utilized during the growth phase. As the alcohol level builds up towards 5%, the yeast find it more difficult but not impossible to take in nutrients and reproduce. So the growth slows down dramatically and the yeast goes into a stationary phase and require very little fresh nutrients. The best time to add nutrients is during the growth phase. Allow the yeast to consume the nutrients present in the wort then add fresh nutrients during the last half of the growth phase. This is ideal but not practical And a question regarding sterol and oxygen 6) From books and articles I've read that sterol levels are important for cell permeability. What are the details on this? Does low sterols cause the wall to "leak", or to become unpermeable? Or does it simply cause some of the transport mechanism to malfunct in general? What do you think about modelling the effiecny of the transporters as increasing with sterols, so that low sterols would basically be blocked and at a high enough sterol levels the permeability would reach the ideal and maximum value? Clayton: Sterols act as a growth factor and will protect the yeast from alcohol toxicity near the end of the fermentation. Sterols play a role in keeping the cell wall fluid (rather than leathery). During the growth phase, the cell wall must be fluid or elastic so that the bud can form. If the cell wall is not elastic enough, the lack of sterols become a growth limiting factor. Near the end of the fermentation the cell wall will become leathery limiting the transport of sugar into the cell but more important it limits the alcohol transport out of the cell thus the excessive alcohol in the cell becomes toxic and will result in a slow or stuck fermentation. I do not know how you will be able to control the rate of sterol production or the total amount. Yeast can produce the precursor squalene with no oxygen, then with very little oxygen, 10 - 15 ppm, it can move squalene up to sterol. And a last but not least, a lag related question 7) Does the yeast absorb all oxygen and nutriutions, or at least until the cellular pools for this are full before starting sugar uptake? Or can the sugar uptake start in parallell even though at slow rate to supply extra energy? Is it possible to set a condition for the start of sugar uptake? Such are "all pools full", or "no nutritions left to absorb"? I have considerd the case were the cells are very low on glycogen, and that the energy supplies from glycogen simply are not enough to power synthesis of sterols and other things during the lag phase - in such a case. Without sugar uptake starting in parallell, a) would yeast would be stuck in the lag phase forever? or b) Would it stop all nutrition uptake and synthesis due to lack of energy, and instead start to uptake sugar - and NOT do any more nutrition uptake? Clayton: If the pitching yeast is healthy, there is enough of everything that the yeast needs inside the cell to start the fermentation as soon as the lag phase is over. The yeast will do many functions at the same time: metabolize sugar, utilize the nitrogen sources, converting it into cell mass, enzymes, DNA etc. Sugar is a nutrient for the yeast also. During the growth phase it metabolizes the sugar to receive energy and along with minerals, vitamins, nitrogen produces cell mass. The yeast does not have to wait for a period of time and a series of things to happen before it can start to convert sugar to alcohol and CO2. 8) Does yeast synthesise sterols exclusively during the lag phase or can it do so later on if there are enough oxygen and other building blocks in the late part of fermentation? Clayton: There is very little activity in the lag phase other than acclimating the yeast cell to its new environment. Yeast produces sterols anytime there is oxygen available and there is a need for it. Thank you for your questions, Clayton Cone "The More I Know About Beer, The More I Realize I Need To Know More About Beer!" - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003 Return to table of contents
Date: Wed, 13 Aug 2003 22:51:23 -0500 From: "Rob Moline" <jethrogump at mchsi.com> Subject: Dr. Cone/ Tobias Fischborn Responds - Fredrik-Part 3 Dr. Cone/ Tobias Fischborn Responds - Fredrik-Part 3 Dr.Tobias Fischborn Tobias Questions 1, 2, 3 & 4: Glucose & Fructose is entering the cell by facilitated diffusion (energy-independent). The driving force is the glucose/fructose concentration gradient across the yeast membrane. The translocation is via a permease (carrier protein) and the transport is coupled to the glucose phosphorylation. Sucrose is transformed by invertase in the cell wall to fructose and glucose and then taken up by the yeast. Maltose is entering the cell by active transport (energy dependent) driven by the proton gradient (H+symport). ATPase expels protons (H+) which then re-enter the cell with maltose. Glucose represses the maltose up-take and its utilization. Glucose concentration higher than 0.4 % w/v impairs maltose uptake by acting both as catabolite repressor and inactivator of maltose permease. The maltose transporter is induced by maltose, repressed by glucose (>0.4 %w/v) and inactivated following growth on glucose or by nitrogen source exhaustion. Maltotriose is believed to have the same or similar active transport system as Maltose. There is a sequence in uptake since maltose and Maltotriose are inhibited by glucose. The transporters are induced by the sugar. Tobias: Question 5 The amino uptake mechanism is similar to the maltose uptake (active transport driven by proton gradient) but different transporter are used. The uptake of some amino acids is repressed by ammonium catabolites. The yeast should still be able to use FAN at a later stage of the fermentation. Tobias: Question 8 Oxygen uptake is at any time and sterol synthesis as well. That is what we are doing in our propagation. Tobias Fischborn - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003 Return to table of contents
Date: Thu, 14 Aug 2003 00:06:45 -0500 From: "Rob Moline" <jethrogump at mchsi.com> Subject: Rob Moline 2003. Dry yeast varieties Rob Moline 2003. Dry yeast varieties Drew, The short answer is "Yes." The long answer is, "It's more complicated than that." No one could have been more perplexed than I at the reduction in strains available, not just to the HB market, but also to the pro's. In fact, the next batch of Brown Ale, one of our best sellers at CABCO is being made with Nott, despite a history of Manchester. Simple truth....365 days in a year...only so many production runs in a year. The more popular strains win out...be they wine yeasts...or bakers....or London. Sad...but true. Yes, there are strains in development...Tobias and his crew work wonders, and I can't wait. Unfortunately, neither he nor I make production decisions. Believe me, sir, when I say no one looks forward to an expansion of strains...or even just a renewal of the old ones more than I....no, especially a renewal of the old ones. In Lallemand's defense, I will offer that while I might not have what I want in strains...at least Lallemand is out here in the trenches with the HBD.... Beyond that sir...I can only add your voice to mine.....and forward these comments.... Sorry, mate, Rob "The More I Know About Beer, The More I Realize I Need To Know More About Beer!" From: "Drew Avis" <andrew_avis at hotmail.com> Subject: Rob Moline 2003. Dry yeast varieties Since we're on the topic of yeast... a question for Rob Moline (or maybe Dr. Cone, I'm not sure). For the past two years I've been using dry yeast for homebrewing almost exclusively - ever since Paddock Wood started carrying the DCL dry lager strains. Before that I occasionally used Danstar/Lallemand Nottingham, Windsor, London, & Manchester (the Nottingham always worked out well). Now, being a proud Canadian, I would love to buy my yeast from Lallemand, but they don't offer the same variety (multiple lager, British ale, Belgian ale, wit/hefe yeasts) as DCL. In fact, Lallemand has *reduced* the variety of dry yeast they offer to the homebrew market. So my question is: is Danstar/Lallemand planning to develop or release any new varieties of dry yeast in the near future? Drew Avis ~ Ottawa, Ontario "The More I Know About Beer, The More I Realize I Need To Know More About Beer!" - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003 Return to table of contents
Date: Thu, 14 Aug 2003 19:54:46 +1000 From: David Lamotte <David at Craftbrewer.org> Subject: Dr. Cone, 2003 - Lager Pitching Temperature Dr. Cone, I would like to add my thanks to you for your generous contributions, and to the previous posters for their thoughtful questions. From previous discussions on the HBD and a number of brewing texts, there appears to be two schools of thought regarding lager yeast pitching temperatures. One suggests that you pitch a lot of yeast at or below the fermentation temp (8-12C) in order to minimise that amount of esters etc produced. The other suggests that you pitch the normal amount at ambient room temperature and begin cooling down to your fermentation temperature once the first visible signs of fermentation begin. My concern with the second method is that the fermentation will proceed at too high a rate unless you have a large 'cooling power' available. Do you have any information on the effect that pitching temperature has on lager fermentations. Thanks again, David Lamotte Fermenting in Newcastle, NSW, Australia Return to table of contents
Date: Thu, 14 Aug 2003 08:39:00 -0400 From: Eric <edahlber at rochester.rr.com> Subject: Dr. Cone, 2003 Dr. Cone, Thank you for your valuable assistance to our homebrewing community. I was hoping you could recommend ways of rapidly increasing cell density in slow growing yeasts like Brettanomyces. What little I have read about them mentions that they exhibit a negative Pasteur effect. How should I alter typical starter procedures for this unique species? Eric Dahlberg Rochester, NY Return to table of contents
Date: Thu, 14 Aug 2003 06:10:02 -0700 (PDT) From: Michael Hartsock <xd_haze at yahoo.com> Subject: RE: Aerobic Yeast Propogation Simply stirring the yeast creates an aerobic environement to encourage growth, as opposed to anaerobic environments which are inherently created by the by products of yeast metabolism. The stirring, in effect, creates a "well-ventilated environment." I simply pop the airlock and give my yeast a good wake-up swirl. Michael ===== "May those who love us, love us. And those that don't love us, May God turn their hearts. And if he doesn't turn their hearts, may he turn their ankles So we'll know them by their limping." Return to table of contents
Date: Thu, 14 Aug 2003 06:16:30 -0700 (PDT) From: Michael Hartsock <xd_haze at yahoo.com> Subject: RE: Exploding CO2 Tanks, Really? The CO2 tanks are not capable of exploding. Explosion is not the danger; propulsion is the danger. If damage is caused to the valve stem of the tank, you risk having a 1000+ psi steel or aluminum rocket fired in an unpredictable direction. Those things can go through cinder block walls. This is not an urban myth, it can and does happen. I add another warning: don't pick up or drag your tank by the valve. Michael Columbia, MO ===== "May those who love us, love us. And those that don't love us, May God turn their hearts. And if he doesn't turn their hearts, may he turn their ankles So we'll know them by their limping." Return to table of contents
Date: Thu, 14 Aug 2003 09:42:29 -0400 From: "Dan Listermann" <dan at listermann.com> Subject: Brain aneurysms and beer Chad Stevens writes about his late father-in-law death and the family's urge to blame it on beer. My father passed away a year ago in April at the age of 74 from the same thing. As far as beer goes, Dad had lost interest in drinking during the last decades of his life. His alcohol consumption was pretty much limited to the very occasional taste of some of my beers or wines. Alcohol could not have played any role in his aneurysm. Dad did enjoy a lot of salt on his food. Dan Listermann Check out our E-tail site at www.listermann.com Free shipping for orders greater than $35 and East of the Mighty Miss. Return to table of contents
Date: Thu, 14 Aug 2003 07:12:59 -0400 (GMT) From: rickdude02 at earthlink.net Subject: Chad's Father-in-Law First let me say that I'm sorry for your loss, Chad. If your Father-in-Law was the kind of guy to knock down 5 Tecates, I'm thinking that you probably lost a good drinking pal in addition to family member. (Disclaimer: I'm not a doctor, but an engineer. I dropped out of the pre-med program my Junior year because I thought that immediate income following graduation was preferable to 6-8 more years of school followed by years of debt payment. Oh, to change such decisions!) As for 3 days elapsing between that event and the aneurysm, well, I think that speaks volumes. If it was perfectly healthy tissue then it would have recovered/healed by then. If the break had occured the day after, I'd say that it was probably the event itself, but even then it would have needed something to work with-- like tissue that was not elastic and made even more brittle by the presence of heavy plaque. On the common sense side: If the constrictive effect of overuse of alcohol was capable of such damage, then we would be much more worried about that than drinking and driving or alcohol toxicity. I think your assesment is correct, Chad. Although the alcohol may have been the straw that broke the camel's back, it certainly wasn't the only culprit, and probably not the most significant, either-- although possibly the last. With a blood pressure like that, somethings got to give eventually. Nonetheless, I wouldn't try to convince your wife or in-laws of this right now. I'm sure they need to blame something in their grief. Rick Theiner LOGIC, Inc. Return to table of contents
Date: Thu, 14 Aug 2003 09:24:48 -0700 From: "Richard S. Sloan" <rssloan at household.com> Subject: Re: Beer in NorCal/Sonoma >> From: "Stefan Berggren" <yeastfarmer at hotmail.com> >> I will be traveling in Sonoma and the surrounding areas >> September 13-21st and would like to get some advice >> on where a beer minded individual should go? Bear Republic is a great pub. I'm sure you'll love it. You might also want to check out - Moylans in Novato (try the Moylans Special Bitter) http://www.moylans.com Lagunitas in Petaluma Moylans in Novato http://www.lagunitas.com Russian River Brewing (opening soon in Santa Rosa) http://www.russianriverbrewing.com 3rd St. Aleworks in Santa Rosa Getting up into Mendocino County you can find Mendocino Brewing (brewpub in Hopland) http://www.mendobrew.com Anderson Valley Brewing in Boonville http://www.avbc.com North Coast Brewing in Ft. Bragg http://www.northcoastbrewing.com I did this loop last year in Sept on day 3 & 4 of my beer vacation and had a good time. You can read about it here http://beeradvocate.com/news/stories_read/438/ Richard Sloan Grosse Hund Brauerei San Diego, CA Return to table of contents
Date: Thu, 14 Aug 2003 12:59:12 -0500 From: MOREY Dan <dan.morey at cnh.com> Subject: Re: Double the Recipe? Dave remarks: >I find on my system the efficiency goes up 5-10% YMMV. A ten gallon batch will have a higher thermal mass than a 5 gallon batch. Assuming the mash vessel hasn't changed or has similar thermal resistance, the larger batch should hold temperature better. This may explain why you have seen an increase in extract efficiency. My last 10 gallon batch, extracted about %10 more than expected (1.051 vs 1.049). I attribute part of the difference to base malt I was using (Dingleman's Pilsner). I believe I was using too low of potential extract value for the base malt. Maybe half (or 5%) of the increase was due to better thermal management. Larry writes: >The key adjustment involved a noticable increase in hop >utilization, requiring me to reduce the amount of hops used. This might be >explained by the increase in the wort wolume, but I find it hard to >understand why more alpha acid would get extracted in 12 gallons than in 6 >when the gravity is identical in both. This is very interesting. It is actually the opposite of what I would expect. I have found very little difference in my total evaporation between a 5 gallon batch and a 10 gallon batch. Regardless of the size, I boil off about 1.35 gallons per hour. I hope some day we all begin to quote evaporation rates in volumes per unit time, not as percent per unit time. It is a function of the brew equipment and the heat transferred to the wort. The reason for discussing evaporation rates, is this should affect the average boil gravity. See digest #4154 and #4155 for more discussion of evaporation rates. A larger batch should start with a higher specific gravity as the wort will be concentrated less because the total evaporation is a smaller percentage of the batch size. Based upon the various IBU predictions available, one would expect a slightly lower utilization with higher average boil gravity. I'm not disputing your results, it just found it interesting. In summary, it appears for homebrewing scales that linear extrapolation is a good starting point. Prost, Dan Morey Club B.A.B.B.L.E. http://hbd.org/babble [213.1, 271.5] mi Return to table of contents
Date: Thu, 14 Aug 2003 14:06:56 -0400 From: "Martin Brungard" <Martin.Brungard at trow.com> Subject: Mash Step Time and Mash pH At the recent National Homebrew Conference, there was an interesting session conducted by Josh? Ebel of Two Brothers Brewing in Chicago. One aspect of that session really knocked me for a loop. They only hold a mash step for 10 minutes before either stepping up or going to the mash out temp. He indicated they use a steam heated tun and they could do temperature increases of about 1C per minute. He did report that they still have a long runoff time of about 90 minutes. The surprising thing was that they report 88 percent efficiency with their mashing process. I have heard for many years that conversion occurs very quickly (~15 minutes) for well modified malt. But, I had not heard of anyone really using that short of a mash step hold time. Based on that session, I've reduced my sacrification mash step hold down to 30 minutes instead of an hour. I guess I'm not man enough to shorten that step any further. I've always used a short step with lower temp steps, so that wasn't really affected. I can report that my efficiency hasn't suffered from the shorter mash when brewing identical beers. It appears that the notion of long mash step times is not necessary. I've seen plenty of recipes that list 60 and 90 minute mash times. Dropping an hour or more off the brew day is very appealing. I would like to hear from others regarding the applicability of the method and any research that may have been conducted on either the homebrew or commercial level. Is anyone else using really short step times like this? In that session, he also reported that it is very difficult to have a too low pH in a mash. He reported that the malt's buffering capacity keeps the mash pH from dropping below about 5.2. This makes sense since there are acid buffers as well as basic buffers in the world. A lot of compounds can become a buffer as the pH changes. I was hoping that someone else had some insight or confirmation of the malt/mash/pH phenomena. So short of dosing the mash with a lot of acid, it seems that a mash will be self correcting on the low Martin Brungard Tallahassee, FL Return to table of contents
Date: Thu, 14 Aug 2003 15:25:56 -0400 From: "Martin Brungard" <Martin.Brungard at trow.com> Subject: Re: Aerobic yeast propagation I read Fred Johnson's report on aerobic yeast propagation with interest. Its great to have folks out there with access to and interest in technical brewing literature. I am a proponent of magnetic stirrers for yeast culturing. I am also a proponent of using oxygen for starters and batches. The data Fred reported did create a change in outlook in the way I will conduct my starters. Chris White reported at his National Homebrew Conference session that White Labs produces their yeast stock using incremental feedings. He also reported that the wort gravity is kept at about 1.020. He also has continuous aeration and keeps it warm. The thing that seems to differ from the information that Fred reported is that I think that White Labs uses malt extract for their feeding. Fred's source indicates that molasses is a better feed stock for the yeast in that it keeps the glucose level low. Low glucose keeps the yeast from making alcohol, creating cell mass instead. Fred cited some data indicating that an incrementally fed, aerated molasses wort is better at producing yeast mass. But the data do not report what the yeast production is if you just use aerated molasses wort without incremental feeding. Maybe its possible to provide one feeding of a molasses wort and still get better results than with a malt wort? I assume that a molasses wort would have to be fortified with yeast nutrients for best performance. I wonder about the wisdom of using a molasses wort instead of a malt wort since Fred's data indicated that it was for Baker's yeast. Hopefully, someone can comment on these aspects. All of this information really firms up some changes that I need to implement. I think they may be useful for others to ponder. 1. Oxygen definitely has its place in my brewing procedures. It appears most suitable for wort aeration for your beer batches. You only want to hit the batch with one or two doses of oxygen in about the first 12 hours after yeast pitching. But for a starter, you want continuous aeration. My simple oxygen regulator doesn't allow me to meter out really low continuous flows, so my oxygen system is no good for continuous use. It does appear that an air pump with sterile filter would be the most economical and workable solution to implement continuous aeration. I agree that an aeration stone may not even be needed when conducting continuous aeration. A magnetic stirrer is needed to keep the starter fully mixed so that the continuous stream of air can keep the wort aerobic. 2. I prefer dry malt extract for my starters since it stores well. I know it has the proper nutrients. But it appears that incremental feeding is a little more important with a malt wort since the glucose level is higher. That means I've got to come up with some sort of sterile drip system to continuously feed or I've got to make several little wort batches to add to the starter periodically. Sounds like I need to consider wort canning to make pint wort batches to add to a starter periodically. I am still interested in hearing if a molasses wort is suitable for our use. 3. The liquid remaining in a starter made with these procedures is definitely not suitable for adding to a beer batch. So dropping the yeast out of solution and decanting the liquid is important. Martin Brungard Tallahassee, FL Return to table of contents
Date: Thu, 14 Aug 2003 21:17:24 -0500 From: "Rob Moline" <jethrogump at mchsi.com> Subject: Dr. Cone, 2003-barley wine-Harlan Nilsen Dr. Cone, 2003-barley wine-Harlan Nilsen Dr. Cone, I am planning on brewing a barley wine as soon as the weather cools off enough so I can maintain a fermentation temp of 65-70 deg. F. It will have an OG of approximately 1.110. I have purchased 3 paks of Nottingham yeast (11 gm per pak) and am wondering if this should be enough yeast for 5 gallons. I have been told that it may be too much yeast but I want enough to promote a good healthy ferment. I will aerate the wort well with pure O2 and add any fermentation aids that you may suggest. Thank you for sharing your expertise. Harlan Nilsen Harlin, It looks like you are going in for a very high gravity fermentation, which means that you will need to increase the yeast inoculum and provide adequate nutrient supplementation. A 11 gram package of Nottingham can readily handle five gallons of 1.048 OG wort, but would have a struggle handling 1.110 OG wort. It would take two packets to comfortably handle this high gravity wort. There is a general rule of thumb for inoculating a high alcohol (high gravity) fermentation: one million yeast cells per ml. of mash per % sugar, Brix or Balling. In the distilling and wine industry, OG, Brix and Balling equals % sugar. This is not true in the brewing industry. Part of the gravity is not fermentable sugars, however, during the first part of the fermentation, the osmotic effect is similar on the yeast growth. Yeast do not multiply in high gravity as well as they do in low gravity, so you have to make up the difference by adding a larger inoculum. Please give special attention to the Nottingham yeast rehydration procedure written on the package. Success or failure often starts with the rehydration procedure. I am not sure how you achieved the 1.110 gravity wort; mashing, malt extract or pure sugar, so I cannot give you an exact answer regarding the amount of nutrients that will be required. Pure sugar adjunct contains no nutrients for the yeast and will require the most supplementation from a well balanced nutrient source. For your interest, yeast require 30% more nitrogen source to ferment a 25% sugar juice than it does a 20% sugar juice. This shows you the importance of giving careful attention to nutrient supplementation. I would add 10 grams of a well balanced nutrient like Fermaid K / 5 gallons wort. Regular gravity wort fermentation require about 8 ppm O2. As you go up in gravity, the O2 requirement increases. You will need about 15 - 20 ppm O2. How do you achieve this is a good question. Large breweries, wineries, distilleries and research centers have good metering devices $$$. It takes about an hour of pumping air, using an aquarium pump, through a porous ceramic stone and just a few minutes using pure O2. I have always been leary of pure O2. You have to make sure that it is not hospital grade. Some hospital grade O2 contains a fungicide. Perhaps some of your colleges can give you advise regarding aeration equipment and timing. Let me know how your barley wine turns out. Clayton Cone - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003 Return to table of contents
Date: Thu, 14 Aug 2003 15:28:14 -0500 From: MOREY Dan <dan.morey at cnh.com> Subject: Increased Utilization with Larger Batches After thinking about Larry's comments some more, I believe there is a simple explanation. It is possible for utilization to decrease, but still end up with more IBUs. The following example is provided as an explanation. Assumptions: 1. Style Robust Porter OG 1.058 IBU ~35 2. Kettle loss 0.5 gallons (wort that remains in brew kettle, below dip tube) 3. Water absorbed by hops in minimal compared to kettle loss. 4. Evaporation loss 1.35 gallons/hr 5. Boil time 60 minutes 6. 1 oz N. brewer at 9% AA for 5 gallons (2 oz for 10 gallons) 7. Hops added at beginning of boil (30% utilization). 8. Use Rager's hop formula 5 gallon batch (collected wort at 1.058) Amount of wort at end of boil is 5.5 gallons at 1.058 (batch size + kettle loss) Volume at beginning of boil is 6.85 gallons (End of boil Volume + evaporation loss) Average boil gravity is 1.0517 ====> 1+ (0.058*5.5/((6.85+5.5)/2)) Gravity adjustment = 1.0085 ====> 1+((1.0517-1.050)/0.2) IBU = oz * util * aa * 7462 / (end of boil volume * gravity adjustment) IBU = 1 * 0.30 * 0.09 * 7462 / (5.5 * 1.0085) = 36.3 IBUs 10 gallon batch (collected wort at 1.058) Amount of wort at end of boil is 10.5 gallons at 1.058 (batch size + kettle loss) Volume at beginning of boil is 11.85 gallons (End of boil Volume + evaporation loss) Average boil gravity is 1.0545 ====> 1+ (0.058*10.5/((11.85+10.5)/2)) Gravity adjustment = 1.0225 ====> 1+((1.0545-1.050)/0.2) IBU = oz * util * aa * 7462 / (end of boil volume * gravity adjustment) IBU = 2 * 0.30 * 0.09 * 7462 / (10.5 * 1.0225) = 37.5 IBUs (increase in bitterness) In this example, the amount of hops was doubled as well as the wort collected. However, the amount of wort produced did not double. It increased about 91% (10.5/5.5 = 1.909), hops were increased more than wort production. Dan Morey Club B.A.B.B.L.E. http://hbd.org/babble [213.1, 271.5] mi Return to table of contents
Date: Thu, 14 Aug 2003 21:29:34 -0400 From: "Jennifer/Nathan Hall" <hallzoo at comcast.net> Subject: Room enough for 10 gallons? Is it possible to ferment 10 gallons in a 12.2 gal TMS conical without blowoff? I want to brew a 10 gal ale using WL California Ale yeast (in a 1 gallon starter). I haven't yet sealed the lid and made arrangements for a blowoff setup. What would you think is the maximum volume you can ferment without worrying about blowoff? Thanks for the help! I hope that those of you on in the Northeast U.S. get your power back soon! Nate Hall BBV Brewery Return to table of contents
Date: Fri, 15 Aug 2003 09:38:43 -0500 From: "Rob Moline" <jethrogump at mchsi.com> Subject: Dr. Cone, 2003- bobz Dr. Cone, 2003- bobz Thank you Dr. Cone for sharing your knowledge. If I want to "grow" yeast fast what would be your suggestions. I have read if you keep a constant temp, O2, limit glucose to >.4% with stirring, yeast will stay in the resportory (growth) state and grow rapidly. I have found limited info on the process. What would be the doubling rate if good constants were kept? Thank you ------- bobz Bob Z. You are almost right. Limit glucose to >.2%. Yeast do not grow faster under these glucose limiting conditions. They grow without the production of any alcohol. This is important for the commercial production of yeast. They want all of the sugar and other nutrients to go into cell mass. Any alcohol produced is waste and ultimately becomes air pollution as the huge volumes of air (thousands of cubic feet per minute) blow through the growth media. On an average the yeast doubles about every five hours under these parameters. The growth rate is limited in order build into each cell the exact composition (minerals, protein, glycogen, trehalose, enzymes, DNA and etc) that is required to harvest a healthy yeast cell with built in stability for storage life. Also the growth cycle is limited the last hours of fermentation to bring all of the cells into synchrony and stop new buds. The growth cycle could be shortened to 3 - 4 hours if cell mass was the only criteria. Yeast can double in less than two hours in a non glucose limiting media. Every yeast strain has its own genetically controlled growth rate. The growth rate decreases as the sugar concentration goes up. A practical level of sugar is 10 - 12 %. A small amount of air is required. Shake flask with a cotton plug will provide enough air. Rich sources of nitrogen, phosphate minerals and key vitamins increase the growth rate. In the early stages of commercial production of yeast the batch process, with 10 -12 % sugar and a small amount of filtered air, is used. Cell mass yield is sacrificed in order to produce alcohol, which minimizes bacteria infection. Glucose limited production of yeast offers greater potential for infection than sterilized batch process. Clayton Cone - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003 Return to table of contents
Date: Fri, 15 Aug 2003 14:10:42 -0400 From: Alexandre Enkerli <aenkerli at indiana.edu> Subject: Dr. Cone 2003, Training Yeast Dr. Cone, Like everyone else, I really do appreciate your help and understanding and I hope my questions won't be too silly for you. We're told yeast will adapt to the medium, at least for scale. But does it also adapt to other characteristics of the medium? If so, would it be possible to lead a yeast strain to adopt different characteristics for further batches? If the adaptation is simply based on selective pressure and random mutations, one would imagine there's little that can be done. Again, thank you for your help. Alex, in Montreal [555.1km, 62.8] Apparent Rennerian Return to table of contents
Date: Fri, 15 Aug 2003 14:16:32 -0400 From: Alexandre Enkerli <aenkerli at indiana.edu> Subject: Dr. Cone 2003, Organic and Engineered Yeast [Don't want to ask too many questions, and this one is really a matter of curiosity...] Dr. Cone, Noticed on the label for Wolaver's brown ale that 98% of the yeast was organic while 2% wasn't. Thinking about your comment on ADN markup, I was wondering if genetic engineering of brewer's yeast might be a significant field of yeast development. Again, thank you. Alex, in Montreal [555.1km, 62.8] Apparent Rennerian Return to table of contents
Date: Fri, 15 Aug 2003 22:22:52 -0500 From: "Rob Moline" <jethrogump at mchsi.com> Subject: Dr.Cone Responds-Jurriaan Boekamp Dr.Cone Responds-Jurriaan Boekamp Dear Dr.Cone, At present I oxygenate my wort inline during cooling with pure (?) O2 as I assume it to be as close to sterile as possible in a homebrew situation and hence more practical than working with an aeration stone and aquarium pump after cooling to pitching temp. Although I have not experienced any problems with fermentation, I wondered what your views on it would be regarding yeast health etc. Thank you for devoting some of your valuable time to answer questions on the HBD. Jurriaan Boekamp Hobart, Australia Jurriaan Boekamp, Both methods of introducing oxygen into the wort are satisfactory as long as you keep the dissolved oxygen in the 8 -15 ppm range. The oxygen transfer rate from an air bubble into the wort is very poor. The oxygen transfer rate from an oxygen bubble is very good, so it is much easier to over oxidize the wort using pure oxygen that it is using air. The pure oxygen technique requires careful monitoring, using a very fine stream of bubbles. A small excess of oxygen results in an added increase of yeast cell mass which is not bad but not desirable. It will effect the ester formation slightly. A larger excess of oxygen can place an oxidative stress on the yeast cell, producing an unhealthy cell with possible undesirable by products. The yeast has a mechanism called glutathione reductase to protect itself against excessive oxygen. The aquarium pump method is inexpensive but carries with it the possible sanitation problem. Good sanitation practices can take care of that. The pure oxygen technique is a Cadillac method but requires close monitoring. You have been successful thus far. Apparently you have mastered the correct timing and flow rates. A colleague of mine has always been leery about hospital grade pure oxygen. He noted that some hospital grade O2 contains a fungicide. He uses industrial grade oxygen. For your interest. The best time to introduce oxygen into the wort is on the second day of the fermentation. The yeast need it the most at this time. Some commercial breweries are beginning to adopt this technique. Double batch fermentations automatically adds oxygen on the second day. Clayton Cone - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003 Return to table of contents
Date: Fri, 15 Aug 2003 22:29:57 -0500 From: "Rob Moline" <jethrogump at mchsi.com> Subject: Dr. Cone Responds- Ken Schramm - Mead query Dr. Cone Responds- Ken Schramm - Mead query Dr. Cone, it is a privilege to be able to seek your counsel. I am curious about mead fermentations. I understand that the low nutrient content of mead musts necessitate nutrient addition(s) to insure vigorous and healthy fermentations. I also understand that staged additions of these nutrients over several days can improve the performance of the yeast. In certain Lallemand strains, including one of my favorites, 71B-1122, the reference chart indicates that this strain has a low tolerance for O2 additions after the initial aeration. Is it best practice in the case of low O2 tolerance to continue using a staged introduction of nutrients or to go with a single nutrient load at the front end? I am also interesting in knowing what deficiencies in nutrient levels lead to fusel alcohol production in wine or mead fermentations. Can specific levels of given free amino acids be tied to production of the higher alcohols so seemingly common in mead fermentations? I see you have many brewers seeking your advice, so I will leave more questions for a later date, if you have the time. Thanks very much for this valuable service. Ken Schramm Ken Schram, Most honey is low in nutrients that yeast find necessary for a healthy cell and a vigorous and healthy fermentation. Yeast do respond better to staged additions over the first 1/3 of the fermentation. All the nutrients added at the beginning will result in a high level of yeast cells with each cell having a low protein content. The fermentation will be vigorous in the beginning then fizzle out towards the end. Staged additions will result is a lower cell population with high protein. This will produce a steady vigorous fermentation up to the very end. The high protein content in each cell will protect the cell from alcohol toxicity near the end of the fermentation. Staged or incremental additions of nutrients, namely nitrogen, will also minimize the production of H2S. A better way to interpret the reference chart regarding 02 and 71B-1122 is: the 71B strain requires less O2 for its growth phase than some of the others. Excessive O2 is not toxic to this strain. The introduction of O2 with staged additions of nutrients is no problem. When there is an excess of amino acids the yeast catabolizes the amino acids via the Ehrlick pathway: deamination and decarboxylation to higher alcohol referred to as fusel oils. When there is a deficiency of amino acids, fusel oils are produced by the biosynthesis pathway from pools of alpha-keto intermediates. Each amino acid is tied in with a specific higher alcohol. An over load of a specific amino acid should reflect itself in an increase of a specific higher alcohol. Clayton Cone - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003 Return to table of contents
Date: Fri, 15 Aug 2003 22:38:40 -0500 From: "Rob Moline" <jethrogump at mchsi.com> Subject: Dr. Cone Responds-wort oxygenation-Bob Devine Dr. Cone Responds-wort oxygenation-Bob Devine Dr. Cone, thanks for the expert assistance! Question: Some British brewers "drop" their fermenting wort up to a day after adding yeast. How effective is this for adding oxygen? And how late can wort be oxygenated? Bob Devine Bob Devine, The optimum time to add oxygen to the fermentation is about 12 - 24 hours into the fermentation.. Active Dry Beer Yeast(does) and re-pitched yeast (usually) have enough lipids for two to three generations. It is at that time the budding yeast can most efficiently use the oxygen to continue to bud and also produce enough lipids to protect itself against the higher levels of alcohol. This is especially true with high gravity brewing. In wine fermentation it is not uncommon to add oxygen to a stuck fermentation near the end of the fermentation when there has been inadequate oxygen added at the beginning. The yeast will not grow but will metabolize the oxygen to produce more lipids that will revive the elasticity or fluidity of the cell wall and allow the transport of the alcohol out of the cell to a safe lever and then begin to transport sugar into the cell again. Clayton Cone - --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003 Return to table of contents
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