HOMEBREW Digest #2955 Tue 16 February 1999

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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

  Fermentation woes (Michael Pratt)
  counterflow chiller design ("S. Wesley")
  yeast under pressure ("Stephen Alexander")
  unitap ("Thomas Kramer")
  candi sugar (Dan Kasen)
  Motors for Malt Mill (Joy Hansen)
  Help (Joy Hansen)
  Re: Dispensing from kegs without a CO2 bottle (Jim Larsen)
  making candi sugar (Dan Kasen)
  Rollmaster mill availability (John Mitchell)
  ice cube momily & creamer tap ("C.D. Pritchard")
  stirplate timer & O2 at kegging & brewery sink ("C.D. Pritchard")
  The Dave Draper Report ("Rob Moline")
  Temperature Controller (Joe KISH)
  an extract brew, but i dare ya to try it ("Gradh O'Dunadaig")
  Racking the lees. (Rod Prather)
  "pulling the decoction": question (LEAVITDG)
  yeast/alcohol tolerance ("Stephen Alexander")
  Ooops (AJ)
  Decarbonating (AJ)
  re: Stir plates that are too hot (Jim Larsen)
  Setup and solution to the CFC problem (part 2) ("S. Wesley")
  Setup and solution to the CFC problem (part 1) ("S. Wesley")
  New Millennium brews... ("Peter J. Calinski")
  Correction to posted MCAB results (Louis Bonham)
  Rochefort Yeast / Sensory evaluation (Nathan Kanous)
  canned priming solutions ("Raymond Lowe")
  Brew Kettles (Mark Garthwaite)
  Hot water freezes faster? ("Eric R. Theiner")
  Autolysis & Rousing ("ajphoto")

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---------------------------------------------------------------------- Date: Fri, 12 Feb 1999 22:07:23 -0500 From: Michael Pratt <Michael.Pratt at Ottawa.com> Subject: Fermentation woes I guess it's time to break down and ask a question. I have been brewing all grain for almost two years. I have been buying my grain and hops from the same source. I have been using water from the same source and treating it with gypsum, burton salts and citric acid in the same fashion for most of the time. My problem is fermentation. I seem to live in a place where pH test papers, iodine tests and certified thermometers are either unavailable or way beyond the price I'm willing to pay. Therefore, I cannot accurately measure the values that my finished mash or wort would exhibit. This year my finishing gravities - for about 8 batches in a row have been over 1.020! I think something is wrong. Previously my FG's were in the range of 1.013-1.016. Sometimes I would get as low as 1.008-1.010 for a low OG beer with a particularly strong liquid yeast. My fermentation temperatures are 59-64F for ales; 54-59F for lagers. I have used Coopers and Munton & Fison for dry yeast; Wyeast 1098? British, 1056 American and 2278 Czech. I have upped my sanitation practices with each batch (although I have never been lax with sanitation in the past). I have tried rehydrating the dry and pitching it straight into the wort. I have tried stepping up the liquid yeast to 1 pint, 1 quart and 1/2 gallon. I have even racked the cooled wort directly onto a yeast cake from a primary. I chill the wort and have never pitched above 68F. I have tried racking off the trub, and leaving it in. I have used yeast energizer. I have aerated by shaking and by using a nozzle and not aerating. I have tried stirring the yeast up after primary fermentation starts. I have purchased a carbon filter for my water. In all these 8 or so batches, I have not seen a vigorous primary fermentation as I used to. It always used to overflow. Now it never does. How can I realize my past experiences? How do I get my primary fermentations to be mor vigorous? HELP Michael Pratt Return to table of contents
Date: Sat, 13 Feb 1999 00:16:08 -0500 From: "S. Wesley" <WESLEY at MAINE.MAINE.EDU> Subject: counterflow chiller design About two years ago I designed and built a counterflow chiller (CFC) for my home brewery. I had a number of design constraints which I wished to satisfy. I wanted to be able to chill 20 gallons in 10 min using the 12C water from my well which can be delivered to the brewery at a maximum rate of 5 gal per min. As part of the process of trying to understand the design constraints of the CFC I developed a set of equations describing the temperature of the wort (hereafter beer-b) and water (w) as a function of position along the length of the chiller(L). I am presenting the results here in hopes that they may be useful to anyone else interested in designing a chiller under similar constraints. These equations were derived using the equation for the rate of heat transfer which can be found in any introductory university physics text: dQ/dt = kA(T1-T2)/d Clearly there is some difficulty in trying to apply this equation to the transfer of heat out of a fluid flowing though one pipe and into the fluid in another because of the poor ability of water to conduct heat away from the metal between the fluids. Creating a turbulent flow will help to allieviate this problem somewhat, but not completely. It is my contention that as long as the parameters involved in this discussion are not varied over too wide a range it is possible to compenstate for this problem by replacing the thermal conductivity "k" in the equation by an "effective k" of lower value which can be determined empirically. Here are the equations which describe temperature of beer and water as a function of position (x) from the beer inlet of a chiller of length (L). Tb(x) = A + Be^(-(S-R)x) Tw(x) = A + De^(-(S-R)x) with B/D = S/R Here S = kp/(wc(phimb)) R = kp/(wc(phimw)) with thermal conductivity (k), tube circumfrence (p), tube wall thickness (w), specific heat (c), and rates of mass flow ((phimb)&(phimw). k = 385 W/(mK) (expected value for copper) k = 4.5 W/(mK) (effective value in my chiller) c = 4190 J/(kgK) p = .040 m (for a .50" diameter tube) or more generally: p = 3.14 x .0254(m/in) x (diameter in inches) w = .0016 m (for a 1/16 th inch wall thickness) or more generally w = .0254(m/in) x (wall thickness in inches) (phimw) = the mass rate of flow in kg/s. in other words the number of kg of water (or beer) entering or exiting the tube per second. This can be easily calculated from the number of gallons per min as follows: phimw = (# of gal/min) x (3.79 litres/gal) x (1 min/60s) (1kg/litre) How can these equations be used to help design a chiller? Suppose you have beer which starts at 100C (Tbi) which you want to cool to 20C (Tbo) using well water which is 12C (Twi). You want to pump beer at 2.0 GPM and water at 5.0 GPM using .500 " diameter copper tubing. How long should the chiller be? 1) Determine the output water temp (Two). Two = Twi + (R/S)( Tbi-Tbo) (44C for me.) 2) Solve for L. L = ln((Tbi-Two)-(Tbo-Twi))/(S-R) (S-R) =.13 (R/S) = .40 to get a chiller length of 15m or about 50 feet, which, coincidentally, is the length of my chiller. Just for reference A = 6.67C, B = 93.3C, and D = 37.3C for my chiller operated under these conditions. These will vary quite a bit from chiller to chiller depending on the design and operating conditons. Return to table of contents
Date: Sat, 13 Feb 1999 07:30:20 -0500 From: "Stephen Alexander" <steve-alexander at worldnet.att.net> Subject: yeast under pressure Simon Wesley writes ... >[...] KARL thinks I'm an ASS Welcome to the club - it's not very exclusive tho'. >Does anyone have information from a reliable resource which discusses >the impact of pressure on fermentation? Specifically, Is there a >point at which the fermentation activity of yeast will be >significantly impacted due to increased pressure, and if so when? 'The Yeasts' Rose&Harrison, Academic Press London, discusses yeast under pressure as relates to wine fermentation with Saccharomyces Cerevisiae var Ovoidum. At 3-4 atmospheres (45-60psi) yeast cease to grow, but continue to ferment. At ~8 atm (120psi) yeast cease to ferment. The higher pressures are used in the wine industry to stop fermentation. - -- Andy Walsh kindly sent me three papers back in 1997 related to beer and pressure: 1/ JIB 90, 1984, pp 81-84, "The Response of S.C to Fermentation under Carbon Dioxide Pressure" 2/ JIB 98, pp 509-513, 1992, "The Formation of Esters and Higher Alcohols During Brewery Fermentation: The Effect of CO2 Pressure". 3/ MBAATQ, 32(3), pp 159-163, "Regulation Mechanism of Ester Formation by Dissolved CO2 during Beer Fermentation". And several others that discuss CO2 levels vs esters w/o added head pressure. Paper 1/ from Heriot-Watt tests ale yeast under pressure ... At >2atm(30+psi) the rate of fermentation, growth and fusel production declines and pH remains higher. The effect on VDKs is variable, but except at very low temps, pressure causes the rate of VDK removal to be the same or higher than w/o pressure for LAGER yeasts. For the ALE yeast under test (NCYC1108) the pressure increased the final level of VDKs. Low pressure (up to 0.2atm/3psi) enhances growth rate. 0.3-0.5 atm(4.5-7.5psi) causes some growth inhibition. 2.5-3.0 atm(37-45psi) prevents cell growth entirely. At 20C/2atm(28psi) the fermentation speed for the ale yeast was about 1/2 normal, the final fusel levels were only 30-75% of normal (varying from fusel to fusel), the final pH was about 0.4 higher, and the final yeast cell count was about 25% lower. - -- The second paper,from Delft U Biochem Engineering, test a lager yeast at 0, 1.0 and 2.0 atm overpressure. They show that the impact of overpressure on fusels is relatively small (5-10% at 1atm, 20-40% at 2atm) compared with the decline in yeast biomass(30% at 1atm, 70% at 2atm). Ester level decrease is the same as biomass decrease at 2atm (70%), and the ester decline is even greater than the biomass decline at 1atm.(50% vs 30%). If you want to minimize esters with a modest decline in yeast growth for lager yeast, 1atm is about right. - -- The third paper, from Suntory Japan, indicates that under pressure yeast have unusually low levels of acetyl-CoA. At 1.5 atm the level stayed around 30-40ugm/g, while in the control (no pressure yeast) the level peaked around 90ugm/gm. They showed that a precursor enzyme, pyruvate decarboxylase, has it's activity suppressed as the dissolved CO2 level rises. AcetylCoA is critical to several aspects of growth and fermentation - so growth inhibition and slow fermentation under CO2 pressure is suddenly less mysterious. Also ester formation involves the interaction of acetylCoA, and alcohol and an enzyme. If the free pools of acetylCoA are low - the ester production rate should decline. Another mystery elucidated. - -- See Andy Walsh's excellent note on ester formation at: http://hbd.org/brewery/library/EstFormAW0696.html for more details ... For my money an overpressure of ~1atm would make some sense for fermenting lagers at higher temps. It's value is otherwise seems limited. Steve Return to table of contents
Date: Sat, 13 Feb 1999 08:41:08 -0500 From: "Thomas Kramer" <tkramer at monad.net> Subject: unitap I went down to my local gas supply store to get a refill on my c02 tank. The guy told me about a new product that they (Merriam-graves a NewEgland Chain) sell for pushing beer out called Unitap. It seems that Unitap in a mix of C02 and nitrogen, they say it's better then C02, it pushes beer faster longer distances with less foam. I wonder if anyone has tried this product, or is it something that bars would use and not homebrews? tom Keene, NH Return to table of contents
Date: Sat, 13 Feb 1999 07:53:20 -0600 From: Dan Kasen <dkasen at flash.net> Subject: candi sugar B.R. Rolya asked about making dark candi sugar. I have made dark candi sugar several times and I start out with brown sugar to make it. Dan Return to table of contents
Date: Sat, 13 Feb 1999 08:45:43 -0500 From: joytbrew at halifax.com (Joy Hansen) Subject: Motors for Malt Mill OK Badger, Here's the best advice I give out when Murphy isn't around to screw things up. Other home brewer friends have worried about how to motorize a malt mill to survive milling 30 pounds of malt without taking an entire day in advance of brewing. Several friends bought high torque, geared motors specific for the purpose. Most failed to have the flexibility and reliability needed for infrequent brewing sessions. Sooooo, . . . I use a 10 year old Schmidling adjustable Malt Mill. Unlike most home brewers, I set the center of the roller gap to 60 thousands. Since this mill was designed (IMHO) for hand cranking, the motor to use must have the same characteristics as the human hand. I choose about 100 RPM as a starting point. My human hand required frequent rests for 20 to 30 pounds of malt. By chance, while I was at a Sears & Roebuck service center, I noted a refurbished 1/2 inch vari- speed/torque electric drill. The unit cost about $40 at the time. I hook it up to the drive shaft of the malt mill in the usual fashion, lock the speed trigger in the full on position, and slow the speed with the vari-torque knob. When the malt starts through the mill, I adjust the vari-torque knob to near 100 RPM. SMALL OR LARGE ELECTRIC DRILLS WHICH CANNOT BE OPERATED AT 100 RPM (imho) ARE NOT SUITABLE TO DRIVE A MALT MILL. The Sears & Roebuck electric drill mentioned is in use by at least two home brewers using the Schmidling Malt Mill. It's operated perfectly over several years and dozens of milling sessions without over heating, gear failure, or shorting out. Different malts being of differing hardness and kernel size require the adjustability of the roller speed and gap. IMHO the roller speed is the most important and easy to adjust if the roller spacing is in the ball park. My setup for the Schmidling mill is 60 thousands in the center. The ends are possibly 40 and 80 thousands; however, I haven't taken the time to check. Too high a speed and most two roller mills become grinders! I don't know if there is such a condition where the speed could be too slow? My purpose in milling is to leave as much husk intact as possible and at least crack the malt kernel without producing mostly fines ( I still get a lot of fines). So, I adjust the speed as different malts, wheat, caramel, chocolate, pale, etc. are milled. I do all this to maximize the flow through my RIMS mash. With Breiss Pale two row, I typically get 28 points. With DC Pale two row, I typically get 33 points. Again, this setup seems to work OK for me. IMHO it will work for you. Joy"T"Brew with BURP (Brewers United for Real Potables) Return to table of contents
Date: Sat, 13 Feb 1999 08:59:59 -0500 From: joytbrew at halifax.com (Joy Hansen) Subject: Help I'm using several controllers prepared by using the schematics in the Rodney Morris article published in Zymurgy Special Issue 1992, pages 49, etc. I thought I had corrections to the publication; however, I can't find them. If you recall what the changes are, I'd sure appreciate the information. Thanks, Joy"T"Brew Return to table of contents
Date: Sat, 13 Feb 1999 08:30:41 -0600 (CST) From: Jim Larsen <jal at oasis.novia.net> Subject: Re: Dispensing from kegs without a CO2 bottle Several people, most recently Phil Wilcox, have posted about this topic. I recall many years ago post in a three-digit HBD from a brewer who had moved to France and was unable to get a hold of CO2 kegging equipment. He conceived of a way to harvest the CO2 from fermentation in a corny and control the pressure using water pressure from the kitchen tap. Does anyone recall this scheme? Jim Larsen Ceverseria Alfresco Omaha, NE Return to table of contents
Date: Sat, 13 Feb 1999 08:47:33 -0600 From: Dan Kasen <dkasen at flash.net> Subject: making candi sugar To make candi sugar see You can Rock Candy Dan Return to table of contents
Date: Sat, 13 Feb 1999 13:52:43 -0500 From: John Mitchell <jlmitch at charlotte.infi.net> Subject: Rollmaster mill availability Back around the middle of 1998, I saw a mill advertised in Zymurgy which appeared to be a good mill. It was called the Rollmaster Roller Mill and the web address given was www.highlander-brew.com. I left the country for a while and when I came back I found the site is no longer around. Does anyone know if they are still in business? Has anyone tried one of these mills? If so, was it worth the money? John Mitchell Gastonia, North Carolina Return to table of contents
Date: Sat, 13 Feb 1999 15:36:29 From: "C.D. Pritchard" <cdp at chattanooga.net> Subject: ice cube momily & creamer tap Hot water won't freeze faster than colder water. I think this old saw probably evolved when someone heard that the heat of fusion (the quantity of heat which must be removed to convert 32 degF water from liquid to solid) is 144 Btu/lb. while 142 Btu/lb. (a bit less) is required to drop water from boiling to 32 degF and brain-farted the old saw. - - - re: the creamer type taps: I don't have bar type taps or the creamer tap- I use cobra taps instead. After about filling a glass, if it needs more foam, I tease the tap open just a bit to dispense a head of foam. c.d. pritchard cdp at chattanooga.net web site: http://chattanooga.net/~cdp/ Return to table of contents
Date: Sat, 13 Feb 1999 15:26:36 From: "C.D. Pritchard" <cdp at chattanooga.net> Subject: stirplate timer & O2 at kegging & brewery sink Philip J Wilcox <pjwilcox at cmsenergy.com> asked: >Electronic timers: >My stirplate... puts out too much heat to use >on an overnight basis. I was thinking of getting a timer to turn on and off >the electricity thus keeping it from getting to hot... Security light >timers... only have one or two settings. Use a control intended for controlling an electric range surface element and splice it in series with the 120 VAC to the heater. They control the heat by cycling the heater on and off with a varible duty cycle. The one I use in with my electric boiler has about a 30 second or so total cycle time with the duty cycle variable from 10% to 100% (~3 to 30 seconds on time each 30 seconds). New ones go for $10-$20 at appliance parts stores (mine is a 120 VAC model F16-713 from Johnstone Supply, $16.65). For less cost, salvage one from a discarded stove. A cheaper and perhaps better option is to try a regular light dimmer. Do NOT splice in either type so it turns the stirrer on/off along with the heater- the relatively short cycle time or chopped voltage may cause the stirrer motor to overheat and maybe even burn out. - - - Rob.Green1 at firstunion.com asked: >Does agitating cornelius kegs during forced carbonation may cause >oxidation? I was following a thread in the archive that hinted at that, but >never saw this issue put to rest. Was this gem posted with the orginal "hot water freezes faster" thread? :-) If you purge the keg of air, there's no O2 to oxidize the brew. I to purge after sanitizing by filling the keg (with disconnects and a hose attached to each disconnect fittings) with Iodophor, letting it sit then applying CO2 via the gas disconnect to force the Iodophor out the liquid line 'til the keg's "empty". Since I have both dip tubes in my kegs whacked off, I shut off the CO2, connect the CO2 on the liquid fitting, invert the keg, and tilt so the gas disconnect is the lowest part of the keg (hint: drill a hole in the rubber keg base opposite the gas disconnect fitting so you can easily hang 'em this way) and apply CO2 to help force the Iodophor out of the gas disconnect. Seal off both hoses, leave up-side-down for 5 minutes or so then open both to allow the residual Iodophor to drain out. Leave ya with everything sanitized and very, very little O2 in the keg. - - - Since there's been a bit of bragging on one's significant others... mine let me take over a spare bathroom for cleaning and storing brewing stuff. Which brings up a brain-fart for anyone planning a home brewery: use a fiberglass bathtube/enclosure as a sink but mount it on a raised base so it's at a height that'll save your back. A storage cabinet as the raised base would be great. Scratched/dented ones go for as little as $50 in these parts- hardly more than what a cheap plastic laundry sink will cost ya. I've hooks attached to the walls of the our enclosure for hang wet stuff to drain like kegs and hoses as well as a bottle draining rack. The enclosure contains all the drips and 3/4 of the spray one gets when a hose or tubing under water pressure gets away from ya :-). c.d. pritchard cdp at chattanooga.net web site: http://chattanooga.net/~cdp/ Return to table of contents
Date: Sat, 13 Feb 1999 22:55:34 -0600 From: "Rob Moline" <brewer at isunet.net> Subject: The Dave Draper Report The Dave Draper Report Dear Friends, Greetings after a long hiatus. I've moved yet again, so that Dave in Bristol,then in Sydney,then in Dallas, is now Dave in Houston. Got pretty much the dream job working with NASA, so now I'm going to be hobnobbing with the Foam Rangers, Mashtronauts, and KGB folks. I'm writing from Rob Moline's hotel room near the end of the first MCAB, a couple of hours after the awards ceremony. It's been a very good event, and Louis Bonham and all his crew deserve a lot of thanks for the excellent job done in organizing and putting on this great show. I had the chance to finally meet Jethro and Spencer Thomas and Jeff Renner (who *can* be bought for $3.50-- I have the receipt) and George dePiro and Phil Wilcox and a whole bunch of others. Lots of great beer and good company, and the awards ceremony inside the St. Arnold's brewery where three of their beers plus a host of other local micros were on tap. All I can say is that anyone who is within range should make an effort to attend next year's MCAB in St. Louis... I know I'll be there. Glad to see you all again.. here's Jethro. Well, it's late at night and the fun has to end! Man, what a great collection of talent that was assembled for this event! Clayton Cone, Chris White, Dave Miller, Paul Farnsworth, George Fix, Ralph Olsen, Chris Mueller, Spencer Thomas, Harlan Bauer, (who has to supercede me by a geometric level of intensity!), George dePiro.............it's been a situation where there simply are not enough hours in the day to hear that they all can say.....or that the attendees can absorb! Anyhoo, we'll say g'day, and hooray....and be off like a piece of cheese! Cheers! Jethro Gump and Dave in Houston (Who has the DREAM JOB!!) Rob Moline brewer at isunet.net "0.00 Miles From, And Two Floors Above (!!!) The Center Of the Brewing Universe, Jeff Renner!!" Return to table of contents
Date: Thu, 11 Feb 1999 01:51:02 -0800 From: Joe KISH <jjkish at worldnet.att.net> Subject: Temperature Controller To: Joy Hansen, The RCA Data Sheet for the CA3059 (in the Rodney Morris temperature controller) says that the resistor on pin 5 of the CA3059 should be 10K 2watt, and NOT 8.2K, as in the drawing. Does anyone else know about more corrections? We would like to hear from you! Has anyone made a printed circuit board drawing? Is it available to the collective? Joe Kish Return to table of contents
Date: Sat, 13 Feb 1999 22:14:30 PST From: "Gradh O'Dunadaig" <odunadaig at hotmail.com> Subject: an extract brew, but i dare ya to try it The Wrath of Gradh for 5 gallons: 6# light syrup extract 2# light DME 8oz crystal 10 8oz munich 2oz columbus leaf (60 min) 1oz eroica leaf (60 min) 1oz cascade leaf (30 min) 0.5oz cascade (10 min) 1.5oz cascade (dry) OG. 1.060 FG. 1.011 THIS IS BEER!!! ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com Return to table of contents
Date: Sun, 14 Feb 1999 03:38:05 -0500 From: Rod Prather <rodpr at iquest.net> Subject: Racking the lees. Dave, Wouldn't this process encourage autolysis. I thought autolysis was a situation where the yeast consumed the hulls of spent yeast. An undesirable flavor in wine as well as beer. It would be desirable to transfer a some of the yeast cake but I question the wisdom of suspending all of the lees in the beer, er, barley wine. As a matter of fact, I was always told to rack off of the lees to prevent autolysis. > For those of you who have been making high "FG" barleywines > try "dropping" the barleywines two or three times during the early > part of the fermentation by racking the wines into other carboys. > Do not rack off the yeast, but transfer all of the contents from one > carboy to another. > > If you have a large enough carboy, use a stirrer made of a dowel > with a new moon shaped blade which can rotate so that it can > be inserted into the carboy and removed. Coat it with > polyurethane and allow it to dry a week before using.Spin the > stirrer to stir up the yeast by rolling the dowel back and forth > using the palms of the hands. > Return to table of contents
Date: Sun, 14 Feb 1999 08:37:25 -0500 (EST) From: LEAVITDG at SPLAVA.CC.PLATTSBURGH.EDU Subject: "pulling the decoction": question I read with interest to post about raising the mash to 149, then pulling the decoction, etc...and have a question: I tried this by taking about 1/2 gallon out of a 4 gal batch, and boiled the whole thing (grain and liquid). Is this ok, ? Or , is it better to try to get just the liquid? ..Darrell <Plattsburgh, NY>...far from Jeff R, but glad we have email so as to keep up on his, and the rest of your posts to this digest. Return to table of contents
Date: Sun, 14 Feb 1999 16:02:19 -0500 From: "Stephen Alexander" <steve-alexander at worldnet.att.net> Subject: yeast/alcohol tolerance Rob - some comments on your 3 part post. 1/ Wow ! Thanks. 2/ Could you give a full citations ? Was this from the MBAATQ, issue, vol ? 3/ My synopsis/comments follow - could you fill in some of the details as you understand them ... especially figure 5 since this might be of considerable practical value to HB high gravity brewers. 4/ Reference 22 is ??? 5/ Did the paper give results for Sterol/UFA/FAN additions alone and in various combinations. If so which appear to be most effective ? I get the impression that added sterol isn't the issue, but FAN (what levels?) and certain unsaturated FA's are. === Brewing yeast can fully ferment high gravity wort with proper nutrition and reach 16.2% alc at 14C/57F, high yeast viability, normal brewing periods. Wort must contain nitrogen supplements (yeast extract, FAN) and either sterol(ergosterol) + UFA(oleic fraction of TWEEN80) supplements. Fermentation then proceeds rapidly DUE TO INCREASED YEAST GROWTH, [not increased alcohol tolerance]. O2 deficiencies can be overcome by either the addition of 24 ppm ergosterol with 0.24% (vol/vol) Tween 80 as a source of oleic acid OR by periods of oxygenation during the fermentation. [Both of these methods have potentially serious negative flavor/head consequences for beer. Chronic human sterol intake around 1mg/day (~1.5 fl.oz at 24ppm) can result in hypercalcemia with CNS consequences - so don't try this at home !] High gravity worts had insufficient FAN. Levels of yeast extract (nitrogen) required can be drastically reduced by the use of an all malt base.(Fig 5). [Rob - can you tell us what is in fig 5 ? This should indicate how much yeast extract is needed when brewing barleywines - no ?] Tolerance to the effects of ethanol on generation time, viability, and solute uptake are enhanced when C18:2 UFA [linoleic acid], rather than C18:1 [oleic acid] was added. [C18:1(oleic acid), C18:2(linoleic) have 18 carbons, one and two degrees of unsaturation resp'y. The unsaturated bond synthesis requires oxygen. The statement above says than linoleic protects yeast from the negatives of ethanol. Is linoleic+FAN the key to high gravity ferments ?] The early rise and then continued decline in fermentative power values has been attributed to an increase in the cellular levels of hexokinase activity by the buildup of intracellular ethanol levels with time(27). [hexokinase is an enzyme that starts off the fermentation process by converting various hexose sugars into their hexose-6-phosphate form. ATP(energy) and Magnesium ions are required. The phosphated sugars have an inhibitory effect on the enzyme(regulation). What is the impact of ethanol on this step ?] Yeast glycogen and sterols were found to differ considerably between anaerobic and semi-anaerobic conditions and on the nutritional supplement used. Glycogen - < 10% semi-anaerobic, unsupplemented or supplemented ~30% anaerobic fermentations [no supplement ??] 10.5% anaerobic, fully supplemented (fastest ferment) Sterol - 0.85-1.09% semi-anaerobic [w/o-with supplement?] 0.27-0.56% anaerobic [w/o-with supplement?] Sterols were not the limit of growth. [!!] [Or else sterol >0.2% is required for high gravity/high ethanol growth. Glycogen is an energy storage carbohydrate, so high levels result from non-carbohydrate growth limits (the energy would be used to grow if possible).] == The addition of sterol *appears* to be unnecessary. Among the UFAs linoleic is most effective than oleic. Will oleic+FAN do the trick ? I still have doubts that UFA additions or mid-fermentation oxygenation will make a tasty beer, but this should add some weight to the idea of repitching healthy well aerated starters with FAN additions. Steve Return to table of contents
Date: Mon, 15 Feb 1999 12:58:58 +0000 From: AJ <ajdel at mindspring.com> Subject: Ooops Yesterday I posted to the effect that clear water (ferrous) iron would oxidize copper. It is, of course, ferric (Fe+++) that oxidizes copper being reduced to Fe++ (clear water iron) in the process. Sorry about the goof. Return to table of contents
Date: Mon, 15 Feb 1999 13:21:30 +0000 From: AJ <ajdel at mindspring.com> Subject: Decarbonating Amen to Adam's comments about boiling as a means of decarbonation. The majority of homebrewers (those in the coastal regions) in the US will be unable to use it because their water isn't alkaline/hard enough. With less hard water when the precipitate forms, if it forms, it is so finely divided that it stays in suspension for ever i.e. it's very difficult to separate the water from the precipitate. And, as Adam pointed out, you don't get all the alkalinity anyway. It is, however, extremely simple to measure alkalinity and hardness and thus residual alkalinity. Looking at Adam's post I'm not sure he means the same thing by "residual" as I do. I'm speaking of Kohlbach's Residual Alkalinity which is calculated by adding half the magnesium hardness to the calcium hardness, dividing the sum by 3.5 an subtracting from the alkalinity. The biggest disadvantage to boiling is that it requires heat. A commercial operation seldom use it for that reason. Addition of lime has the same effect, uses no energy (except that required to stir the mix), is safer, as effective and adds some calcium in cases where starting pH is low (i.e. residual alkalinity is reduced through bicarb decrease _and_ calcium increase). Boiling may be prefferable where chlorine/chloramine need to be eliminated as well as bicarbonate. Return to table of contents
Date: Mon, 15 Feb 1999 07:28:31 -0600 (CST) From: Jim Larsen <jal at oasis.novia.net> Subject: re: Stir plates that are too hot You might try lifting the flask off the plate with a piece of bent coat hanger or the like. If this does not reduce the temp adequately, run a small fan, like the sort used to cool your PC, over the plate and under the flask. Jim Larsen Ceveseria Alfresco Omaha, NE Return to table of contents
Date: Mon, 15 Feb 1999 09:15:15 -0500 From: "S. Wesley" <WESLEY at MAINE.MAINE.EDU> Subject: Setup and solution to the CFC problem (part 2) Consider a slice of width (dx) located at some position x along the chiller. The rate of heat transfer (Q is heat) is given by the equation dQ/dt = [Tw(x) -Tb(x)]kp(dx)/W. The change in beer temperature (dTb) is related to dQ by the equation dQ= dmC(dTb) and dt = dx/Vb. Here m is mass, C is specific heat and Vb is velocity. Putting all of this together gives: [(dm)(Vb)C(dTb)]/(dx) = [Tw(x) -Tb(x)]p(dx)/W, or (dTb)/(dx) = [Tw(x) -Tb(x)]kp(dx)/[W(dm)(Vb)C] the differential element of mass can be replaced by dm = (rho)[(Ab)(dx)]. Here (rho) is density and [(Ab)(dx)] is the volume of the differential element of mass. (I am making the approximation that the densities of beer and water and the specific heats of beer and water are the same). Substituting and canceling gives (dTb)/(dx) = [Tw(x) -Tb(x)]kp/[W(rho)(Ab)(Vb)C] The combination of (rho)(Ab)(Vb) is simply the mass flux or mass rate of flow of beer through the system. This combination can easily be calculated from the flow rate in Gal/min using the equation in my earlier post. So with (phimb) = (rho)(Ab)(Vb) The equation becomes: (dTb)/(dx) = [Tw(x) -Tb(x)]kp/[W(phimb)C] By similar arguments (dTw)/(dx) = [Tw(x) -Tb(x)]kp/[W(phimw)C] the eqation for water can be derived. Let us simplify these equations further by making the substitutions: S = kp/[W(phimb)C] and R = kp/[W(phimw)C (dTb)/(dx) = S [Tw(x) -Tb(x)] and (dTw)/(dx) = R [Tw(x) -Tb(x)] Fortunately, this system of coupled differential equations can be solved by inspection. The equations show that Tb(x) and Tw(x) have the same derivative (except for a multiplicative constant) indicating that they are probably the same function except for additive and multiplicative constants. The function is therefore essentially proportional to its own derivative indicating an exponential (decay in this case) function of some sort. Tb(x) = A + Be^(-Gx) and Tw(x) = C + De^(-Gx). Further reflection tells us that A = C since additive constants will be lost when differentiating the left side of the equation and they can only be lost on the right if they cancel out in the subtraction. Tb(x) = A + Be^(-Gx) and Tw(x) = A + De^(-Gx) The value of the decay constant G can be found by differentiating the two functions and substituting them into the differential equations. -GBe^(-Gx) = S(D- B)e^(-Gx) and -GDe^(-Gx) = R(D- B)e^(-Gx) canceling the exponential gives -GB = S(D-B) and -GD = R(D-B) dividing the two equations gives B/D = S/R and substituting gives G = S-R. The question most people want to answer when designing a CFC is "How long should I make it?" This can be answered using the equations I gave at the end of my previous post. I suggest using my empirical value of k = 4.5 W/mK as a starting point. If you expect to run your system a lot slower you should probably reduce this value. I seem to remember that there is enough data in Pat Babcock's comparison of CF and immersion chillers at the brewerey website to get another value of k for a slower flow system. Return to table of contents
Date: Mon, 15 Feb 1999 09:15:14 -0500 From: "S. Wesley" <WESLEY at MAINE.MAINE.EDU> Subject: Setup and solution to the CFC problem (part 1) The subject of the mathematical solution to the CFC problem shows up peoriodically on HBD and is just as regularly dismissed as complex and therefore too difficult to solve. In reality the method of setting up and solving the problem is accessible to anyone who has a basic understanding of calculus. Furthermore the solutions, once derived, can be used by anyone who knows how to use the exponential and natural log keys on a scientific calculator as I demonstrated in a post which is still in the queue at the time of writing. In HBD #2954-7 Mike Swintosky suggests that the problem can be approached more simply by simplifying the copper layer between the two counterflowing fluids and he is right on target. One of the major problems with the solution to this problem is that it requires the use of a heat transfer coefficient which must be determined empirically. One of the advantages of this is that is absorbs any errors introduced by approximations leaving an equation which has the right functional form. What this enables you to do is understand how changes in things such as chiller length, (wall thickness??), tube circumfrence and flow rate will affect chiller performance in a reliable mathematical way as long as k does not vary too much as the other quantities (most notably flow rate) are varied. Now for the solution. Imagine two rectangular pipes of length L separated by a common boundary which is a sheet of copper. The sheet of copper has a length L and a width p equal to the circumfrence (perimeter?) of the inner copper tube. The thickness of the sheet (W) is equal to the width of the tube wall. One pipe of area Ab carries wort (hereafter beer-b) in one direction and the other of area Aw carries water in the other direciton. Let length along the tube be described by x and the temperature of beer and water at a particular point be described by Tb(x) and Tw(x) respectively. Beer will flow in from x=0 and water from x=L, so Tb(0) = Tbi (Temperature of beer in) and Tw(L) = Twi (Temperature of water in) Similarly Tb(L) = Tbo and Tw(0) = Two. Return to table of contents
Date: Sat, 13 Feb 1999 22:37:35 -0500 From: "Peter J. Calinski" <PCalinski at iname.com> Subject: New Millennium brews... >Hey, just a thought, if you are making a 'New Millennium' barley wine....it >will have plenty of time to age. You will drink it in 2001..... >Year 2000 isn't the change of the millennium, 2001 is. We started at year 1, >not year 0.... >Just a thought.... Another thought. Shouldn't the O.G. be 2.000 ? Pete Calinski East Amherst NY Near Buffalo NY 0 Degrees 30.21 Min North, 4 Degrees 05.11 Min. East of Jeff Renner Return to table of contents
Date: Mon, 15 Feb 1999 08:17:21 -0600 From: Louis Bonham <lkbonham at hypercon.com> Subject: Correction to posted MCAB results Hi folks: The results I posted yesterday had an embarrassing typo -- the winner in American Brown was in fact Chris Lavoie, and not Robert Acosta and & Pete Rodriguez. In typing up the results Sunday after getting about 8 hours sleep over the previous 3 days, I just didn't proof it carefully. (Cut and paste error in creating the winner list from the list of entrants.) I've already sent an e-mail to Robert Acosta and & Pete Rodriguez apologizing for the snafu. Rest assured that the proper winner was announced at the MCAB on Saturday, and that I had 2 other people cross check my handwritten list of winners against the beer ID sheets before we announced the winners. Louis K. Bonham Return to table of contents
Date: Mon, 15 Feb 1999 08:42:17 -0600 From: Nathan Kanous <nlkanous at pharmacy.wisc.edu> Subject: Rochefort Yeast / Sensory evaluation Hi Everybody! I've got a starter of Rochefort yeast going. One thing I've noticed is how dry this yeast finishes. I made one previous batch using this (Wyeast 1762) and noticed how much more bitter this beer tasted than the IBU's would have indicated for a brew of such OG and FG. So, how does the dry finish of this yeast impact on sensory perceptions? What I'm really asking, is what charactersitics of beers meld well with this dry finish? It appears that the bitterness of a given brew may be accentuated by the dry finish. What about hop flavors? Would a yeast with a dry finish go well in a beer with a relatively high level of finishing hops? Is this yeast better suited to a really malty HUGE beer? Kind of a strange question, but I've never been accused of being much else. Any thoughts would be appreciated! TIA....oh yeah, anybody brewed with this yeast got any experiences to pass along? Thanks. nathan in Madison, wi Return to table of contents
Date: Mon, 15 Feb 1999 10:04:32 -0500 From: "Raymond Lowe" <WRLowe at worldnet.att.net> Subject: canned priming solutions Brewers, I have a question. I made priming solutions that I canned in the pressure canner. I did this in pint jars. I measured 4.5oz corn sugar to each jar and filled with water. Canned in the pressure canner for 15min at 15lbs. pressure. Has anybody else tried this? I have used this in my last 2 beers, and they seem a little sweet after conditioning. Could this have caramelized in the pressure canner?They seem to have a slight tint to them. When mixed, before canning they were clear. I was canning wort for yeast starters when I got this idea.Thanks for the help Raymond Lowe Catawba, Virginia Return to table of contents
Date: Mon, 15 Feb 1999 09:36:09 -0600 (CST) From: Mark Garthwaite <mgarth at primate.wisc.edu> Subject: Brew Kettles Rodney asks of a source for a brew kettle for full-wort boils... I've had good luck at restaurant auctions (restaurants that are going out of business). They are few and far between but great sources. -Mark Mark Garthwaite Madison, WI Return to table of contents
Date: Mon, 15 Feb 1999 10:56:16 -0500 From: "Eric R. Theiner" <logic at skantech.com> Subject: Hot water freezes faster? We're getting far afield from beer, but I have a chip on my shoulder regarding people who refuse to examine the facts in preference of their own (possibly incorrect) beliefs. Call it a side effect of conducting pure research for too long. This reference and abstract came from a web site that I suspect the naysayers ignored. If anyone wants to challenge the subject statement, please argue with the research rather than resorting to vulgarities. Am. J. Phys., Vol. 63, No. 10, October 1995 Pages 882-885 Supercooling and the Mpemba effect: When hot water freezes quicker than cold David Auerbach Max-Planck-Institut fur Stromungsforschung, Bunsenstrasse 10, D-37073 Gottingen, Germany (Received 2 November 1994; accepted for publication 28 March 1995) Temperature measurements taken near vessel walls show that initially hot water may well begin to freeze quicker than cold. This is not, as previously surmised, due to the cooling history of the water (e.g., air expulsion during heating). Rather, supercooling virtually always takes place. On those occasions where the cold water supercools sufficiently more than the hot the Mpemba scenario is the following: The hot water supercools, but only slightly, before spontaneously freezing. Superficially it looks completely frozen. The cold water (in larger volume than that of the hot sample) supercools to a lower local temperature than the hot before it spontaneously freezes. This scenario can occur more often for ambient cooling temperatures between -6 (degree)C and -12 (degree)C. (Copyright) 1995 American Association of Physics Teachers. Rick Theiner LOGIC, Inc. Return to table of contents
Date: Mon, 15 Feb 1999 10:54:19 -0500 From: "ajphoto" <ajphoto at columbus.rr.com> Subject: Autolysis & Rousing What effect would rousing of the primary have on the flavor contribution of autolysis byproducts? I sometimes notice lighter versions of the flavors mentioned though I never exceed two weeks in the primary even for Lagers and high gravity ales. I often agitate the primary to lower F.G. Is this increasing the flavor transfer? I wait to be sure that there is CO2 in the headspace before I rouse. A.J. Zanyk Return to table of contents
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