HOMEBREW Digest #3838 Mon 14 January 2002

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  Carbonation calculator ("Steve Jones")
  IBU Calculations In ProMash (Jeffrey Donovan)
  Hops Calculations (AJ)
  Re: Force Carbonation & Keg Cooling ("D. Butler-Ehle")
  Promash hop calculations (Pat Babcock)
  Paulaner Hefe-Weizen Clone Recipe? ("Jodie")
  What's the cause ...... (Andy Woods)

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---------------------------------------------------------------------- Date: Sat, 12 Jan 2002 09:00:31 -0500 From: "Steve Jones" <stjones1 at chartertn.net> Subject: Carbonation calculator In response to the recent question about calculating pressure on force carbonating, I've built a javascript calculator that isn't limited to a specific range of temps or volumes CO2. I've not tested it yet for Netscape, but here is a link to my brewing calculators page. On it is the calculator for force carbonation, among several others: http://users.chartertn.net/franklinbrew/tools.htm. Steve Jones Johnson City, TN stjones1 at chartertn.net http://users.chartertn.net/franklinbrew Return to table of contents
Date: Sat, 12 Jan 2002 06:51:52 -0800 From: Jeffrey Donovan <jeffrey at promash.com> Subject: IBU Calculations In ProMash Richard, >Richard Foote wrote: >I have been using ProMash for a few months now. One thing that keeps >hitting me is the hop bittering calculations. It seems to take way less >hops to achieve a desired bitterness level than I was accustomed to over >many years of using long hand calculations and other brewing software. Ok I will try and do my best to answer this question Richard, hopefully something in the following statements will click for you: 1) The underlying formulas for all of the hop IBU calculators are for the most part identical, it is the utilization calculation that is different in each. You mention you feel the numbers are too high and that you are using the default setting in ProMash. The default is the Rager calculation, and I personally would agree that Rager numbers are usually a bit high, hence you would use less hops. Have you tried using any of the other formulas such as Tinseth or Garetz? I personally use Tinseth's formula, and most of the brewers I talk to feel Tinseth is the most accurate of the three. Both Tinseth's and Garetz's formula will give IBU values lower than Rager. The reason we set the default to Rager is that this is the formula that has been published the longest, and most brewers are familiar with it (most IBU utilization formulas, with the exception of Tinseth, are based on Rager's work). 2) I have had the opportunity many times to take my own beers to a lab and have them analyzed. Again, the Tinseth formula's prevail as the best fit in almost every example (best fit, not exact match). However, I can tell you right now that IBU calculations are *not* mathematical truth, nor will they ever be. The best we can do is be accurate in the equations presented, and we have had all of our equations independently verified by their respective author. If you would like to see how the different formula's do stack up in the Lab, I refer you to Louis Bonham's excellent article written for the now defunct Brewing Techniques magazine. http://www.brewingtechniques.com/library/backissues/issue7.1/bonham.html 3) What version of ProMash are you using? One problem we have had in the past is that we include in the download section separate version for both Home Brewers and Pro Brewers. While the actual program is identical, the system settings are set to each scale accordingly. Now, in earlier version we set the "Kettle Utilization" factor in the pro-scale settings to accurately reflect the majority of kettles within the 17 bbl range . However, we quickly discovered many homebrewers were downloading the pro version because they thought the versions were different, and then *not* resetting the kettle utilization factor to accurately reflect smaller scale brewing systems (if your brewing 25 gallons or under this setting should be set to 1.0). In version 1.6 we changed this so that each version (when downloaded) defaults to a value of 1.0, leaving it to the pro-scale brewers to set their correct value. 4) If you want to provide a example of the formula you use in you hand calculation, or name the other software you are using, I could perhaps be of more assistance in determining the discrepancies you are seeing. Finally Richard states: >figure how to get back into wherever I need to go to change it. Goto the System Settings, Hop section. The default is set to Rager. All the variations are outlined in the help screens, so just press the "Help" button in the system settings, hop section to get a full rundown. I hope this helps some Richard. If you'd like to talk more regarding this subject please feel free to contact me via email (jeffrey at promash.com) or visit our Message Board on the ProMash website. Cheers! - Jeff Jeffrey Donovan Beer Engineer The Sausalito Brewing Co. jeffrey at promash.com jeffrey at beerengineer.com http://www.promash.com http://www.beerengineer.com Return to table of contents
Date: Sat, 12 Jan 2002 22:19:45 +0100 From: AJ <ajd at zai.com> Subject: Hops Calculations Rick Foote asks about the hop utilization calculations in ProMash. The ProMash bitterness calculators cannot be expected to accurately predict the actual bitterness of your beer any more than any other method can. There are simply too many variables. ProMash accounts for many if not most of them. You have a choice of three models (Rager, Garetz and Tinseth) for actual isomerization as well as a model for diminution of alpha acids over time. The reason there are three models is beacuse no one has been able to pick a "correct" model and that is, at least in part, because if the perfect model were stumbled across, it would be hard to verify it. In order to do that one would have to relate something measureable in the hops (alpha acid percentage) to something measureable in the beer (bitterness) but this last is a subjective quality. Brewery labs do measure alpha (and beta) acid levels in hops but this is by no means a perfect measurement. Simialrly, brewery labs do measure the absorbance of a gasoline extract of the beer at 275 nm resulitng in the BU values which "express the bitter flavor of beer satisfactorily". Everyone agrees that utilization (percent of hops resin that gets converted to bittering principal) depends on the length of the boil and most agree that it depends on the concentration of the wort. It also depends on kettle geometry and a host of other factors. What this means is that the differnce that a particular brewer sees in utilization between an hour's boil and a half hours's boil may not be the same as seen by another brewer and that implies that it is unlikely that any particular model will exactly match the results any brewer would obtain. About all that can be done about this is to try to correlate the bitterness of the beer with the expected result. Without measurement this is difficult to do but I think an educated palate can guess bitterness to within plus and minus 5 or perhaps even plus and minus 2 with lots of experience with beer similar to the beer being tested. This means that the brewer at a micro or brewpub can probably maintain his output to within something like those limits. The problem, of course, is that we don't have values for reference beers. Pilsner Urquell is at about 35 BU and American Megaswill at about 14 i.e. near threshold. Brewers never put bitterness data on their labels (it's rare enough to see even ABV in the US). Even with measurement you are likely to be surprised. I do measure the bitterness of most of my beers and, where the hops are from a well known supplier and have been kept frozen I'll see things like a measured 46 for a predicted 42 or a measured 17 for a predicted 15 but where I've had to measure the hops alpha myself (rather than rely on a packagers information) because the hops came in ziplock bags from the club buys, I've had some real surprises notable among which was a pils that was supposed to come out 45 and measured 70 (which, after lagering for a year turned into a really nice beer). A.J. Return to table of contents
Date: Sat, 12 Jan 2002 16:36:44 -0500 From: "D. Butler-Ehle" <ulfin at portup.com> Subject: Re: Force Carbonation & Keg Cooling Doug Hurst writes: > >You can force carbonate your keg at room temperature. Just pump your >keg up to about 30psi and let it sit a couple of days. Check it twice a >day and re-pressurize as needed. If I'm in a hurry, I can carbonate it in about 10-20 minutes. Of course it works best when the beer is chilled. (Look at the charts: CO2 solubility skyrockets as temperature drops... if you have any way to chill it at all, do so.) I have done it with warm beer too, though, but it takes a lot longer. (BTW, I'm refering to Cornelius-style soda tanks here, not beer kegs.) I crank up the pressure and shake the keg 'til either I don't hear the gas rushing in or my arms get tired. Rest and repeat as needed. Note, however, that the fuller the beer tank (i.e., the less headspace), the less vigorously I'm able to shake the tank, lest I get beer splashing up into my gas line (and I hate that [btw, opaque tubing is designed to hide spots and yeast sediment; I recommend using clear hose for everything, so you can actually see that it needs to be cleaned/discarded {except maybe the drain tube from your drip tray; you don't want to see what's growing in that}]). The splashing can be avoided by removing the gas disconnect before shaking, then reconnecting it to give the tank another charge, and repeating. Unfortunately, if you don't have much headspace to pressurize, you won't be adding much CO2 with each charge and it'll take a lot of reps. When I guestimate that it has enough, I shut off the gas, give it a final good shake (to ensure that the head pressure has reached equillibrium), let it settle for a few minutes (to reduce foaming due to turbidity and to allow incidental liquid to clear from the gas plug's draw tube), then check it with my pressure gauge(*). With pressure and temperature readings and a target for vol CO2, a quick look at a chart (I use Byron Burch's values as presented by Dave Miller in _Brewing the World's Beers_ [I think it's also in his _Homebrew Guide_]) tells me how close I am. If I overshot, first I try to convince myself not to worry about it and figure that giving it a shake after I've served a few pints will drop it into range. However, if determine that I can't live with it that high, I (carefully) bleed some off using the pressure relief valve in the lid (some very old models don't have them). Give it a good shake, let it settle, then recheck the pressure. >To serve, you will have to reduce the >head pressure to about 4psi (depending upon your tapping/beer line >configuration) Quite so. That's is a point that many homebrewers don't quite understand. The pressure needed to maintain your carbonation at your tank temperature is not necessarily the same pressure needed to force the beer through your system. When they're not the same, you either have to serve the tanks quickly or regularly re-adjust your carbonation level because the dispensing pressure is too low or too high to maintain it. Commercial beverage dispensing installations are individually designed such that the needed dispensing and maintenance pressures will be equal. They adjust hose diameter, length, resistance; vary the storage temp from the dispensing temp; add compensators or restrictors; change rise (or fall) from tank to tap; or even add non-soluble gas. Be careful connecting a warm, carbonated keg to a gas line that's set to dispensing pressure. The backpressure may drive beer foam into your regulator (I don't trust the check valves to protect me). Don't connect the gas until serving it has lowered the head pressure. >There are a couple of ways to cool it. You could fill a couple of >growlers from the tap and cool them in the refrigerator You may lose a lot of the carbonation as you draw from the tap at room temp; warm beer can't hold its breath as well as cold beer, and is much more sensitive to aggitation. Overcarbonating it a little might help some. Chillin' in da U.P., Dan Butler-Ehle [411.4, 327.6] Apparent Rennerian (*) My gauge is a constructed of a disconnect (gas ball-lock x 1/4" male flare nipple) a female adapter (FFL x FFL) a quarter-turn stopcock without check valve (MFL x 1/4" MNPT) a 3-way female union T (FNPT) a 60 psi pressure gauge (MNPT) another stopcock (MNPT x MFL) My gas hoses have FFL swivels. With stopcocks at either end of the gauge tool, I don't have to disconnect anything to check pressure or to keep beer out of the line if I'm shaking it vigorously. Return to table of contents
Date: Sat, 12 Jan 2002 17:07:32 -0500 (EST) From: Pat Babcock <pbabcock at hbd.org> Subject: Promash hop calculations Greetings, Beerlings! Take me to your lager... Richard asks about ProMash hop bitterness calculations... > I have been using ProMash for a few months now. One thing that keeps > hitting me is the hop bittering calculations. It seems to take way less > hops to achieve a desired bitterness level than I was accustomed to over > many years of using long hand calculations and other brewing software. > What gives? Has anyone ever checked the accuracy of ProMash by having > hopped wort samples analyzed. I know ProMash allows you to choose from > three different calculation methods. I use the default method. Can't > figure how to get back into wherever I need to go to change it. > > Open discussion of this would be most welcome. Odd! I have to wonder what hand calculations you are using, or what the other software might have been using? I know that Jeffrey Donovan, the software's architect, had the calculations reviewed by Rager, Tinseth and Garetz, and they've concurred with his algorithms for their hop utilization calculations. I also know that he has implemented every possible variable to those calculations upon which you have control on your brewing. Rather than truck on down the road of formal analysis, why not use your senses? Are the beers brewed using ProMash-calculated recipes much different than previous renditions? If so, which is closer to the target style? Were you, perhaps, overhopping before? Still, I'm betting that the problem is that you were using a calculation method other than the default in ProMash, so your problem lies in not being able to fathom how to change the settings. I can fix that! The key to most disparities between ProMash and other methods is that ProMash leaves nothing to assuption - you need to set it up! You can select calculation method, and tweak utilization for mash and first wort hopping methods (!) as well as adjust the utilization scale factor for your kettle size. Plus, you can CHOOSE whether to adjust utilization for plug and pellet. You must, however, set it up. These are all set very simply from the "Options" pick on the ProMash menu. From there, pick "System Settings" (only pick under that menu :^), then click on the "Hop Calculations, Utilization and Storage" button. Hit the radio button for the desired set of calculations, hit "OK". While there, set the other variables affecting the hopping rates as they pertain to your brewery (mentioned above) then click "Save As Default". You're now golden! Set the calculation to what you used before, and I'll bet the hopping levels become a bit more familiar :^). Another point: hopping rate calculations and the algorithms to implement them are not "science" - otherwise, there wouldn't be Garetz, Tinseth and Rager methods; there'd be a "Hop Calculation Formula" accepted by all (and I don't believe any commercial brewers are using one of these three methods for estimating hopping rates, so there's even more). Each of the three are estimated predictions against the reality, and each is different with its own error function. Automation of such formula can induce additional error (or difference) from your hand calculations based on the precision of variables maintained in the calculation. Typically, you won't even notice the difference; however, if there is a small difference between your hand calculation and that of ProMash, this could be the source as well (never bothered to compare. I selected my favorite hopping rate calculator, and noticed no appreciable change to my hopping schedules from the many years I'd brewed without PM.) One man's answer. Others? - -- - God bless America! Pat Babcock in SE Michigan pbabcock at hbd.org Home Brew Digest Janitor janitor@hbd.org HBD Web Site http://hbd.org The Home Brew Page http://hbd.org/pbabcock [18, 92.1] Rennerian "The monster's back, isn't it?" - Kim Babcock after I emerged from my yeast lab Saturday Return to table of contents
Date: Sun, 13 Jan 2002 10:05:35 -0500 From: "Jodie" <jodie at ga.prestige.net> Subject: Paulaner Hefe-Weizen Clone Recipe? Yesterday my husband and I found ourselves waiting for a table at The $3 Cafe in Kennesaw, GA sitting at the long bar in front of the beer coolers. Being a new brewer we figured we'd try something new--research you know. Since we have both gravitated toward wheat beers I suggested the Shiner Hefeweizen. Great label and, oh, nice beer. We shared two before we were called to the table. When we ordered our burgers my husband asked for another hefeweizen. The waitress returned with a Paulaner. Wow! Even better. This one was spicier than the other, with almost a clovely touch. Winner! So, of course we now want to brew a similar beer. Can anyone direct me to a recipe to replicate this brew? As I mentioned, we're just beginning and don't have a mash set up (yet, but I see that coming! ;) ) so a malt/partial grain recipe would suit us at this stage. Thanks for any help, Jodie Barthlow Return to table of contents
Date: Sun, 13 Jan 2002 23:00:34 -0500 From: Andy Woods <woods_a at ACADMN.MERCER.EDU> Subject: What's the cause ...... Hello all, Im having a tough time evaluating a fault in a beer made by a friend. He made a clone of a Heineken Special Dark with Kolsch yeast. At the time of racking and bottling, the flavor was very good. But when tasting a finished bottle the flavor was gone, very bland, had good head when pouring, but no bubbles afterwards. I am fairly sure that it isnt phenolic cause of my recent bouts with infection. It has been conditioning for 3 weeks, and like I said, is very bland, similiar to a stale soda. Any suggestions?? Andy Woods woods_a at acadmn.mercer.edu Return to table of contents
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