HOMEBREW Digest #4909 Mon 12 December 2005

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  Sanke Parts ("MARTIN AMMON")
  Re: Achieving that typical British bitter character (Signalbox Brewery)
  hyperbole ? ("steve.alexander")
  Re: Cake-taking record anal CO2 tracking (John Schnupp)
  Change is constant... ("Pat Babcock")
  Science News article on beer (Bob Devine)
  Clinitest and fermentation, carbon dioxide measurements and fermentation ("Dave Burley")

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---------------------------------------------------------------------- Date: Sat, 10 Dec 2005 07:26:53 -0600 From: "MARTIN AMMON" <SURFSUPKS at KC.RR.COM> Subject: Sanke Parts Looking for sanke part the seal that goes into the spear at the check ball. I have seen only two different types because of the two different balls one being a bearing and the other a stamped out piece. Tried sabco no luck. Kansas Swagman Its Never Too Early Only Late Return to table of contents
Date: Sat, 10 Dec 2005 20:37:32 +0000 From: Signalbox Brewery <signalbox.brewery at ntlworld.com> Subject: Re: Achieving that typical British bitter character Dave Riedel observed: >but I do find that ales >from Conniston Bluebird Bitter, Fuller's London Pride, Blacksheep Bitter, >and the aforementioned Wychwood beer to Gale's HSB all share similar >attributes: a dry, hoppy (but not resinous), almost tight flavour profile >commonly with what I perceive as a slight metallic edge, a balanced caramel >component and a noticeable, but fairly restrained hop aroma. They are all >very enjoyable beers and they all seem to elude me as a brewer! >Does anyone have some advice on achieving the 'British bitter' character? Pasteurise. I think that's what you are describing. I believe that UK breweries are not so clean as North American ones and pasteurise more heavily. What you describe (and I don't doubt your observation of what you get over there) is nothing like the Bluebird on sale at the brewery tap, which has an aroma of hops on speed. It won a prize in the "Beauty of Hops" competition (100% Challenger, by the way). David Edge, Derby, UK Return to table of contents
Date: Sun, 11 Dec 2005 14:59:21 -0500 From: "steve.alexander" <-s at adelphia.net> Subject: hyperbole ? A recent posts caught my attention as defying common sense. Dave Burley posts ... << Once the fermentation begins neither a hydrometer nor a refractometer are any good [...] >> Not so. The Balling relationship for anaerobic fermentation allows us to *estimate* the relationship between sugar used and ethanol & CO2 production and thus SG change. Given OG & currentSG it's quite possible to determine the amount of sugar used to within a few percent. There are published tables for brewing which allow some detailed corrections (used for terminal alc%). Also because the fermentable sugars that normally appear in all-malt wort have a rather similar index of refraction and ethanol a rather different one, it is also possible to come to a reasonably accurate estimate of fermentation progress based on change of refractometer readings (I assume ProMash does this calc). Both estimates deteriorate the already limited accuracy of hydros and refract's, and that's my point. << Clinitest is the only way to determine sugar content once fermentation has begun [...] >> Certainly not true. Clinitest(a form of Fehling's test) is not the only measure of wort/beer sugars. Of course there are enzyme assays, chromatographics techniques and several others. Clinitest is a cheap home test readily available. It has several limitations which Dave failed to mention. Clinitest gives only 3 bits of resolution (only 8 color comparison panels), cannot be used by the color-blind, has dubious accuracy in dark beers, measures the concentration of all reducing ends, not just fermentable sugars, fails to measure any non-reducing fermentable sugars (sucrose!). Yes it is a a direct measure of reducing-ends. Despite the limitation it is useful in determining an ESTIMATE of remaining fermentables in very late fermentation. On a suggested method - most, if not all diabetic blood glucose meters measure only glucose via an enzymatic reaction. You could use acid to hydrolyze all(most) of the dextrins and sugars to glucose (and other primary sugars). This could be used as a relative measure of fermentation progress. Also note that these meters are not very accurate nor repeatable as compared to the apparent resolution, and the top/bottom range is quite limited. -S Return to table of contents
Date: Mon, 12 Dec 2005 00:13:23 -0800 (PST) From: John Schnupp <johnschnupp at yahoo.com> Subject: Re: Cake-taking record anal CO2 tracking Ken Anderson <kapna at adelphia.net> said >I might have to take the prize here. I use an inexpensive >(eBay) mass flow meter, and I love the thing. It gives me a >constant snapshot of the fermentation's progress. <snip> >Here's one of the resulting graphs, as an example: >http://users.adelphia.net/~aken75/ I recall having a conversation with someone, maybe AJ, about the size MFM that might be needed. This was quite a while ago, quite possibly two years or more. I'd be interested is knowing a little more about the equipment and how you have it all connected. Do you have any pictures on your page? John Schnupp, N3CNL (once in a) Blue Moon Hombrewery [560.2, 68.6] Rennerian Georgia, VT 95 XLH 1200 Return to table of contents
Date: Mon, 12 Dec 2005 11:32:48 -0500 From: "Pat Babcock" <pbabcock at hbd.org> Subject: Change is constant... Greetings, Beerlings! Take me to your lager... After wading daily through hundreds of SPAMs, trojans, and virus-laden emails in order to get to the few real posts and emails each day, I've decided that it is time to update the HBD mail handling systems to a more modern, more efficient architecture. Over the Christmas break, I will be implementing a new mail handling system to the HBD network. All mail will be handled external to the main HBD server, and absolutely every piece will be subjected to the rigors of virus and SPAM filtering. This action may result in posts destined for the HBD being tossed out as SPAM as it "learns" the HBD environment - we will eventually overcome any such issues as we have with other filtering systems I've implemented over the years. I simply felt it important to let the subscribing community know what's coming. I will update you all on timing when I'm closer to installing the new servers. Hopefully you won't find out via an email outtage :o) All the best! Pat Babcock Chief Janitor The Home Brew Digest janitor at hbd.org Return to table of contents
Date: Mon, 12 Dec 2005 14:01:56 -0700 From: Bob Devine <devinebob at gmail.com> Subject: Science News article on beer >From the latest issue of Science News: http://www.sciencenews.org/articles/20051203/bob8.asp Bob Devine http://www.frappr.com/hbd -- now has 250 homebrewer locations Return to table of contents
Date: Mon, 12 Dec 2005 19:15:23 -0500 From: "Dave Burley" <Dave_Burley at charter.net> Subject: Clinitest and fermentation, carbon dioxide measurements and fermentation Brewsters: Bill Velek asks if any sugar test used for diabetics would work to evaluate the sugar content of a beer during fermentation. The short answer is "no". The long answer is that these modern tests are very specific to glucose ( which is relevant to diabetes) and ignore other sugars, since most of these quick stick tests are based on a specific enzyme recovered from a fungus ( Aspergillus niger, I think) . In wort there are many kinds of sugars and each is consumed (or not) at a different rate and differently by various yeasts. With a few minor exceptions noted below, the sugars fermentable by yeast are the reducing sugars like glucose, fructose and such. So detecting just glucose would not do the job. A less sophisticated ( but just the thing for us) test procedure is one based on Fehling's/Bennett's procedure of reacting a copper ion with sugar under alakaline conditions to produce an orange/brown, non-stoichiometric precipitate of various copper oxides/hydroxides. The completeness of this reaction is measured colorimetrically by comparing the reaction solution color with a standard color blot. Your eye is able to distinguish thousands of shades so it is very accurate at estimating the amount of sugar in the sample by doing a direct comparison. The color of this sample is derived from the mixture of blue of copper sulfate and the orange of the copper oxides. Orange means all the copper is exhausted. Blue means none of the copper was exhausted( ergo no sugar) . The various shades of green ( orange plus blue) in between tells you the amount of sugar in the sample when compared to the standard. So you can extract 2 or 5 drops of fermenting wort and carry out a test in 30 seconds with no concern for bubbles ( FAR more important than the minute contribution of yeast) interfering with a reading. You do not have to be concerned with temperature and best of all you are not imputing anything or using density of the solution as a surrogate for sugar content You are measuring sugar <directly> in the presence of alcohol and carbon dioxide - and, yes, yeast - and not getting any interference. If you want to use this test at higher than 2 or 5% sugar content all you have to do is prepare a sample by diluting the wort/beer by a known amount and put it through the test procedure. Then correct for your dilution. There is a third problem with beer when compared to wine ( where the hydrometer procedure originated) and that is the solids in beer wort are not all fermentable unlike the majority of the solids in wine, so imputing the alcohol content is not a straightforward procedure unless you know exactly the % unfermentable solids. Of course, we rarely do, if we are all grain and especially if we buy kits which may have varying amounts of sucrose added to the malt extract mixture. You can assume such a % unfermentable ( as these procedures do) but your results wll be off by some amount. So what are the caveats in using Clinitest? Every test procedure has them. Not really very many if you understand a few things. In fact, these caveats are very useful in following the fermentation situation. Clinitest will not indicate positive with pure sucrose ( your table sugar has a little fructose and glucose in it) so if you measure your wort with added or already there sucrose the response will not indicate the sucrose presence. Now <here> is the only place to use your hydrometer - no bubbles and no alcohol. If you pitch the yeast and then take a reading in a few hours you might find that the Clinitest reading is higher than after you first made up the wort with sucrose.. What has happened is that the invertase in the yeast has inverted the sucrose to fructose and dextrose ( glucose) to which the Clinitest is responsive. Clinitest is not responsive to Lactose commonly used in making Milk Stout, so don't expect the reading to go up, except for the impurites of reducing sugars in the lactose. Clinitest, however, is responsive to the reducing trisaccharides in the wort so these will give you a reading of 1/4% - 1/2 % at the "end" of the fermentation. If you are using a true lager yeast these will be consumed over the next few weeks of storage on the yeast in the secondary and you will find you will get a reading of 0% to 1/4 %, typically This will not happen with ale yeast nor with ale yeast masquerading as lager yeast. BTW when you get to these low values there is no problem with using all beer and no water in the test and correcting your readings. This will double your ability to read these lower values. Of course, the hydrometer can not even come close to this accuracy. So now where do you get this marvelous test? From your pharmacy ( they will have to order it) or beer/wine hobby store. You must specify the Clinitest KIT. It will come containing a testube, an eyedropper some reagent pills and a color chart. You just take say 5 drops of beer 5 drops of water in the testube,shake and drop in the pill wait 30 seconds for the reaction to finish, shake and compare the color of the testube with the color chart. You may have to go to 2 drops and 8 drops of water if the sugar content is out of range. - --------------------------- And now to using carbon dioxide emission as a measure of fermentation progress. I am sure you have opened a bottle of beer ans asked youself "Why doesn't this come to equilibrium with atmospheric pressure instantly by gushing out of the bottle?" I am sure if you had a bottle with water and nitrogen or hydrogen and popped the top it would gush out. Or if you shook that beer bottle first it would come firing out and get your date all wet ( hey, maybe not such a bad ideas if she is wearing only a t-shirt). Now why would mechanical agitation do something if the equilibrium was just chemical in this case? It's not. The answer - clathrates - or that is the presumption. The carbon dioxide molecules are trapped in a close association of hydrogen bonded water molecules ( imagine a cage) . Shaking has just about 5 kcals per mole of energy input and that is about the energy of formation of the clathrate. Shaking breaks up that clathrate. When you open that bottle - instant equilibrium with the atmosphere and maybe a wet date. Now that I have Fredrik's attention. The carbon dioxide emission from a solution of carbon dioxide in water is dependent on the rate of breakup of these clathrates in equilibrium with the formation of these clathrates. If this is the slow step in this kinetic series, that is what you will be measuring, not the rate of formation of carbon dioxide. Therefore, your measurements do not represent the rate of formation of carbon dioxide from the fermentation. These reaction rates are, of course, temperature dependent, as is the saturation ( to which it is related) . I suggest you follow the progress of the fermentation with Clinitest and compare it with your method of measuring the carbon dioxide bubbling out. And let us know your results. Keep on Brewin' Dave Burley Return to table of contents
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