HOMEBREW Digest #3023 Thu 06 May 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

  bubbles and gas solubility (pretty long post) ("Czerpak, Pete")
  Tomahawk hops ("Don Van Valkenburg")
  re: SureScreen (Jack Schmidling)
  Lifting converted-keg kettles ("Donald D. Lake")
  RE: Sure Screen (LaBorde, Ronald)
  Kettle carmelization for Scottish/Scotch Ales (beanish)
  Mead Questions (Ted McIrvine)
  non-conversion (SClaus4688)
  enzymes ("Stephen Alexander")
  food grade, fast drying, heat tolerant sealant? ("Sandlin, Jonathan Mark - BUS")
  Tomahawk Hops ("Fred Waltman")
  A little N2/CO2 foam decay measurement... (william macher)
  Listermann (John Herman)
  Signed, Sticky Armpits (ThomasM923)
  The Jethro Gump Report ("Rob Moline")
  clear Weizen (ensmingr)
  re: clear hefeweizens ("Anthony & Julie Brown")
  Guinness Heads ("Rob Compton")
  Flux removal (IndSys, SalemVA)" <Timothy.Rhode at indsys.ge.com>
  cleaning crowns (MicahM1269)
  re: Ring Around the Porter ("David Kerr")
  Re: AOB Tax Designation Change (Steve Jackson)

Beer is our obsession and we're late for therapy! 2000 MCAB Qualifiers: Spirit of Free Beer! Competition 5/22/99 (http://burp.org/SoFB99); Oregon Homebrew Festival 5/22/99 (http://www.mtsw.com/hotv/fest.html); Buzz-Off! Competition 6/26/99 (http://www.voicenet.com/~rpmattie/buzzoff) 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. **SUBSCRIBE AND UNSUBSCRIBE REQUESTS MUST BE SENT FROM THE E-MAIL ACCOUNT YOU WISH TO HAVE SUBSCRIBED OR UNSUBSCRIBED!!!** IF YOU HAVE SPAM-PROOFED your e-mail address, the autoresponder and the SUBSCRIBE/UNSUBSCRIBE commands will fail! Contact brewery at hbd.org for information regarding the "Cat's Meow" Back issues are available via: HTML from... http://hbd.org Anonymous ftp from... ftp://hbd.org/pub/hbd/digests ftp://ftp.stanford.edu/pub/clubs/homebrew/beer AFS users can find it under... /afs/ir.stanford.edu/ftp/pub/clubs/homebrew/beer COPYRIGHT for the Digest as a collection is currently held by hbd.org (Pat Babcock and Karl Lutzen). Digests in their entirity CANNOT be reprinted/reproduced without this entire header section unless EXPRESS written permission has been obtained from hbd.org. Digests CANNOT be reprinted or reproduced in any format for redistribution unless said redistribution is at absolutely NO COST to the consumer. COPYRIGHT for individual posts within each Digest is held by the author. Articles cannot be extracted from the Digest and reprinted/reproduced without the EXPRESS written permission of the author. The author and HBD must be attributed as author and source in any such reprint/reproduction. (Note: QUOTING of items originally appearing in the Digest in a subsequent Digest is exempt from the above. Home brew clubs NOT associated with organizations having a commercial interest in beer or brewing may republish articles in their newsletters and/or websites provided that the author and HBD are attributed. ASKING first is still a great courtesy...) JANITORS on duty: Pat Babcock and Karl Lutzen (janitor@hbd.org)
---------------------------------------------------------------------- Date: Tue, 4 May 1999 10:17:42 -0400 From: "Czerpak, Pete" <Pete.Czerpak at siigroup.com> Subject: bubbles and gas solubility (pretty long post) A number of people have posted on gas bubbles and bubble coalescence (little bubbles joining to become big bubbles) and N2 solubility in water/beer. I went back to my old physical chemistry book and a few handbooks and here is what I came up with. i am glad that i can actually use those 2 semesters of p-chem every once in a while, especially when its brew related. this is a longer post by the way. CO2 solubility: at 45 deg F, 1.33 at 55 deg F, 1.083 N2 solubility: at 45F, 0.0199 at 55F, 0.0175 units of solubility for the above are on a volume basis and are mL gas dissolved measured at standard conditions when dissolved in 1 mL water at the above given temps when gas pressure is 14.7 psi. I do have the solubilities over a full range of useful temps and will post them or a data fit if people are interested in the temp dependence. data was taken from Lange's Handbook of Chemistry 14th edition. Onto bubbles, someone posted a surface tension relationship for bubble diameter. yes, there is a pressure difference between the bubble and the bulk fluid. it is essentially what keeps the bubble from collapsing on itself due to the liquid surface tension constantly pulling on itself. however for small bubbles, this pressure difference is pretty tiny. for example, in a "beer" solution which I approximated as 95% water and 5% ethanol and at 45 deg F, a bubble with a diameter of 2 mm yielded a pressure difference of 0.02 psi between the inside of the bubble and the outside of the bubble. just for everybodys info: the surface tension of my "beer" at 45F is about 71 dyne/cm and decreases with increasing temperature. The eqn is called the Laplace eqn and is correctly given as: pressure inside bubble - pressure outside bubble = 2 surface tension / bubble radius >From this you can see that smaller bubbles have a higher difference in pressure at a fixed liquid surface tension. Also to note, if you want to decrease bubble size (ie. make a nice fine head) you need to either lower your surface tension or increase the pressure difference. perhaps malted wheat causes surface tension to lower. maybe someone could measure the differece in surface tensions for equal gravity worts, one made with wheat and one with normal barley. also perhaps the high serve pressure of pilsners, etc. helps makes the fine head. the driving force behind bubble coalescence is really thermodynamics. bubbles have a certain surface free energy that always is minimized. this is how one actually can derive the above given equation from thermodynamic principles. anyways, when 2 bubbles collide and stick, the total surface free energy is not at a minimum. from the above always heading towards minimum total free surface energy idea, the surface area shrinks by the bubbles walls merging to a new larger single bubble and the total surface free energy is minimized. about nitrogen use in Guiness and the like. I have discussed this with some co-workers and we have thought that they chill the beer and pressurize the beer at high gas pressures using the mixed gases to get more of the N2 in solution. then the temperature is raised slightly and the pressure let up so that the beer is supersaturated with N2 in solution. this is probably similar to a liquid having more that a soluble amount of solid dissolved in it where the temp is raised, more is dissolved, and the temperature is lowered again without the excess dissolved solid material crashing out of solution. however, usually for supersaturated liquids, adding just a bit more solid material in a supersaturated solution will cause large amounts of solids precipitation. hope all who wonder now feel enlightened. and boy do I really feel like a chemical engineering geek spewing forth all that useful knowledge I thought i would rarely use. feel free to debate or comment. Brew on, Pete Czerpak pete.czerpak at siigroup.com Return to table of contents
Date: Tue, 4 May 1999 07:48:57 -0700 From: "Don Van Valkenburg" <ferment at flash.net> Subject: Tomahawk hops In HBD 3021 someone (didn't put name in post) asks about Tomahawk: I have heard that Tomahawk are the same as Colombus. Tomahawk are sold by Yakama Chief and Colombus by Hopunion. They both are indead super-high alpha hops. One thing should be known about super-high alpha hops. They are generally considered "alpha unstable" that is to say they lose alpha real fast. If packaged at 17%, they will be somewhat less when you go to use them - especially if not kept below 32F. Don Van Valkenburg brew at steinfillers.com www.steinfillers.com Return to table of contents
Date: Tue, 04 May 1999 08:45:44 -0700 From: Jack Schmidling <arf at mc.net> Subject: re: SureScreen "Jeff Beinhaur" <beinhaur at email.msn.com> asks " My last resort is the old "hairy arm" technique.... Not sure what that means but one of the things many folks fail to mention on the rare occasion that screens clog is that they used Irish Moss. Although the last time I said this, lots of folks said they have no problems, I tried it once and ended up with a jello coated screen and a hopeless mess. If your hairy arm is used to scrape the screen while trying to drain, that too will guarantee failure. The hops function just like the grain bed in mashing and any disturbance of the filter bed will quickly clog the screen. Keep in mind, the screen is not the filter, the grain/hops is/are. All the screen does is keep the crud from clogging the spigot with the initial rush. In the event of a clog from hops, gently blowing on the end of the hose will usually clear it but stirring and scraping will never work. Some folks swear by whirlpooling but if the wort is given adequate time to settle, nothing but opening the spigot should be required. If you are using a pump, then nothing but an act of god should cause problems. js - -- Visit our web site: http://user.mc.net/arf ASTROPHOTO OF THE WEEK: http://user.mc.net/arf/weekly.htm Return to table of contents
Date: Tue, 04 May 1999 11:47:34 -0400 From: "Donald D. Lake" <dake at gdi.net> Subject: Lifting converted-keg kettles After successfully brewing 5-gallon batches with my new converted keg brewing kettle, I would like to step up to a 10-gallon batch. I see one major problem with my current setup--lifting 11 gallons of boiling liquid up off of the burner to a higher point so I use gravity to run the hot wort through my counterflow chiller then into the carboy. With 5 gallon batches, the weight was testing my limits. I am hoping someone has come up with a technique so that two people can lift that red-hot kettle, safely. Don Lake Orlando, FL dlake at amuni.com Return to table of contents
Date: Tue, 4 May 1999 10:54:36 -0500 From: rlabor at lsumc.edu (LaBorde, Ronald) Subject: RE: Sure Screen >>>> From: "Jeff Beinhaur" <beinhaur at email.msn.com> Problem is that lasted about 5 seconds and then nothing. With all of the hops and I assume break material the SureScreen was clogged. In the past I've tried a stainless steel scrubby around the screen and this helps but it still gets clogged. I've tried whirlpooling but maybe I don't know how to do this either. <<<< You said whole hops, so this setup you are using should work well for you. One thing that happened to me and it may be your problem is that I was using a racking cane without the end cap with the scrubby screen and clogging was quick and complete. What I discovered was that the cane went to the bottom of the screen, blocking the entrance hole and stopping it up. Next time I kept the little cap on the racking cane inside the scrubby, and this prevented the clogging. Try using the cap next time and don't push too hard on the cane, or it will go to the bottom of the scrubby. Ron Ronald La Borde - Metairie, Louisiana - rlabor at lsumc.edu Return to table of contents
Date: Tue, 4 May 1999 12:52:18 -0400 From: Jeff Knaggs <jak at absoft.absoft.com> Subject: RE: MI hops-grower needed >herb-farmer, to produce hops on her farm in northern Michigan. Word has ... >greenhouse. My mother is in need of advice, however, from an experienced Tell her to call the county Agricultural College (Michigan State Univ.) Cooperative/Extension office. They were helpful when I decided to put a few in my back-yard. If she is serious about quantity, I suggest she also call an extension office in one of the counties in Washington where hops are still a big commerical crop -- they will have lots of literature. Jeff Knaggs Return to table of contents
Date: Tue, 4 May 1999 09:52:10 -0700 (PDT) From: beanish at blarg.net Subject: Kettle carmelization for Scottish/Scotch Ales Someone asked recently about Noonan's instructions in the style series Scottish Ale book about kettle carmelization. I've done things that way a couple of times for extract brews, and what I found worked well was this. I mixed the liquid from steeping or partial mash and put it in a 5 gallon pot, added most of my extract, and filled with hot water. Once the extract was dissolved, I positioned this pot above my kettle, started a syphon into my kettle, and lit my burner. I'd then add the rest of the water to get up to my boil volume, any additional extract, and proceed normally. The first time I tried it I turned on my burner full blast, and it resulted in a somewhat scorched taste that wasn't entirely pleasant. I've since found that a more moderate heat level works wonderfully. I'm not sure if it was the carmelization, or the yeast (a Scottish yeast, fermentation at 58-60F), or what, but my latest Export ale had a wonderful flavor behind the maltiness that was somewhat smoky, but more balanced and appetizing than what I've gotten with a peat-smoked malt. Seeing how nice this came out, I have no interest in using smoked malts in any future Scottish ales. I haven't brewed a Scottish/Scotch with my new all-grain setup yet, but instead of running my first runnings into the kettle (not really practical anyway for my setup - I sparge into a kettle at ground level and then lift to my kettle) I'll probably collect a gallon or two, and then do something similar to what I described above. Syphon those runnings into my brew kettle with the heat at a moderate level. Since I've been brewing this way I've also started washing my kettle with a TSP solution, seems to be good at removing the small level of scorching that I get on the inside bottom of my pot from the kettle carmelization. - -- Jeremy York beanish at blarg.net Return to table of contents
Date: Tue, 04 May 1999 14:26:59 -0700 From: Ted McIrvine <McIrvine at ix.netcom.com> Subject: Mead Questions Honey that has a stronger flavor can be great for meads, although if you also use fruit, you will hide some of the honey characteristics. I prefer to add the fruit to the must (don't boil the honey!) just after turning off the heat, and I leave it in the primary fermenter for a couple of weeks. Try at least two pounds of fruit per gallon unless you will also use fruit extract at bottling. If you use more than 2 lbs of honey per gallon, the alcohol will wipe out any wild yeasts on the fruit during the long fermentation. Don't bug your mead; let it sit in the secondary as long as you can, especially if you use fruit. (Six months isn't a long fermentation for a fruit mead.) Mead can be bottled as still or sparkling. Sparkling mead shouldn't have as much carbonation as beer (it should be similar to a gently-carbonated cider.) Depending on your yeast strain and the quantity of honey, it may be hard to carbonate without force-carbonating from a keg. Some meadmakers use gelatin for clarifying, many use Sparkaloid (tm) which is terrific except it requires multiple rackings. Cheers Ted > From: Thomas S Barnett <barnets at mail.auburn.edu> > Subject: Mead Questions > > First of all, i found > some locally produced 'Wildflower and Red Clover Honey' which i was hoping > to use. Is this a suitable variety, or should i use the lighter > varieties? Secondly, how should fruit additions be prepared, how much > should be used, and when should they be added? And finally, what > carbonation levels are appropriate? Thanks. Tom Barnett. Return to table of contents
Date: Tue, 4 May 1999 16:59:58 EDT From: SClaus4688 at aol.com Subject: non-conversion Greetings fellow brewers. It's been a very long time since I've made any contribution to the HBD. I am afraid I am coming back under the humblest of circumstances, having just gone through the most frustrating brewing session of my decade long (occasionally semi-maniacal) homebrewing career. With all the recent posts about lawnmower beer, and with summer not too far off, I decided to try my hand at one. My grain bill called for 14 pounds of Belgian two row pilsner malt, 3 pounds of flaked rice and a half pound of carapils for a 10 gallon batch (with the moderate efficiency of my system, I was shooting for a SG around 1.047). I'm no stranger to adjuncts, having experimented with corn starch, corn grits, oatmeal, flaked barley and even pumpkin. However, this was the first time I'd used rice, and I chose flaked rice specifically because I've read that it does not require a separate cereal mash. I live in Portland, Oregon, which has EXTREMELY soft water (1.8 ppm Ca++, 0.75 ppm Mg++, 1.6 ppm Na+, 10 ppm Cl2, 0.5 ppm sulfates and 7.5 ppm carbonates). I usually use gypsum to bring the Ca++ level up, but, because this was going to be a lager, I used CaCl2 instead. I'll admit right here that I am not even close to understanding water chemistry, but I followed the directions on the label of the CaCl2 package which said that adding a teaspoon to 5 gallons of water would add 95 ppm of Ca++. I did an upward infusion mash, starting at 122f, going immediately to 135f and resting for 10 minutes, then to 151f for saccharification. The mash still iodine tested very starch positive 6 hours later. Why? That's what I've been asking myself for two days. I've got four theories: 1. Flaked rice might need some kind of special handling, rather than just dumping it into the mash. Adding credence to this theory is the fact that the mash didn't really have much solid in it other than grain husks when I dumped it out -- it was just really milky. 2. The Belgian two row pilsner malt did not have enough diastatic power to convert the rice. I didn't really worry that much about this beforehand, because the rice was only about 20 percent of the grain bill. 3. I did not use enough CaCl2 to allow the mash to acidify properly. OTOH, I've made pilsner in the past with NO water adjustments and it converted fine (using a decoction mash). OTOOH, because it's spring, we're having a heavy runoff from the mountains here (our water source) which undoubtedly has an affect on both the content and treatment of the water coming out of my tap. 4. The brewing gods are very angry because I have tried to make budmilloors. Anybody have any theories of their own? If I don't figure this out pretty soon, I'm going to have to rip out my lawn and sell my mower. -Steve Claussen in PDX Return to table of contents
Date: Tue, 4 May 1999 17:47:58 -0400 From: "Stephen Alexander" <steve-alexander at worldnet.att.net> Subject: enzymes Marc Sedam writes >>I agree completely *BUT* starch and >>particularly amylopectin molecules trap water much more effectively than ... >. <snip> >I'm not sure this is true. In a past life I did a lot of work with >purified enzymes and their stability in industrial processes. The >enzyme supplier (who shall remain nameless) stabilized their enzyme >preps with sorbitol (a sugar) and some basic antioxidants. I was trying ... There are two related factors stability and activity. Sugars, sugar alcohols and a number of carbohydrate compounds can greatly stabilize certain hydrolase enzymes. In one paper they suggest that trehalose (a storage carbohydrate in yeast) is actually more important as an enzyme stabilizer for dormant yeast than for stored carbohydrate energy value. Some of the same amylase enzymes that are stabilized by sugars are also inhibited by them - but that is a different thing. See below. So both increased stability and inhibition (lower activity) may occur when these carbohydrates and sugar alcohols are present. This isn't contradictory. A completely different phenomena was being discussed in my comments above. Water is required for enzymatic hydrolysis to occur. Water is just as necessary for alpha-amylase to act as is starch, and in fact the relationship between the concentrations of starch and enzyme vs measured (not specific) activity follow the same kinetic rules as do the relationship between the presence of free water molecules and activity. It's referred to as the Michaelis-Menton equations. If water concentrations are too low, the rate of hydrolysis drops off. The measured activity drops. Most enzymes are more stable when water is absent, but they are of course inactive without water. >Another important aspect of enzyme stability is the existence of >sufficient cofactors. Alpha-amylase is stabilized by the existence of >calcium...yet another reason to make sure your water chemistry has >sufficient calcium in it (>50ppm). According to the paper "Calcium Requirement for Stability and Enzymatic Activity of Two Isoforms of Barley Aleurone Alpha-amylase", J.Biol.Chem, vol264, #32, pp 19392, 1989 .... The amount of calcium required for stability of the least stable barley alpha-amylase (there are several) was in the range of tens to hundreds of microMols of calcium - no more than 4ppm of calcium. You are likely to get this amount from the malt alone. If >50ppm were required then Plzen would be producing starchy beers - they don't. Dr.Dave comments ... >What does happen sometimes is the thick mash impacts >the rate of saccharification since sugars impede the >amylases in performing their duties. This is enzyme inhibition and not what I was referring to. My comments were that water is a necessary reactant in any hydrolysis and at mash thicknesses at and below 1.5qt/lb mashes are demonstrably slowed by the lack of available (free) water. >Interestingly enough ( as often happens in brewing) this is >not a linear function, as the thicker the mash, the more >stable the beta amylase. So that, apart from what we >might forsee as a greater fermentability at higher ratios. >this is reversed for some cases due to the longer life >of the beta amylase in the more concentrated mashes >allowing it to split more of the higher carbohydrates. >(p. 220 M&BS 1ed, 1971) I agree, but the explanation contributes to the muddle that persists in most HBers minds. Less available water (thicker mashes) does increase stability AND decrease measured activity. To understand the final outcome one must compare the rates at which these occur. Typically the loss of enzyme due to temperature related denaturing is the greatest rate determining factor in the system - a couple degrees C for increase cannot be outweighed by the other factors under reasonable brewing conditions. For a given temperature, often, as Dave suggests, increasing thickness gives more final product (for example a thick 60C mash will allow more of the protease activity, a thick 70C mash will allow for more beta-amylase formed maltose than a thin one), but the M-M relationship would indicate that this won't continue at progressively thicker mashes. The malt with 4% moisture in the sack will probably self-convert at room temperature in a few centuries - but we can't wait than long for beer. Somewhere below 1qt/lb (a 2.0 liquor to grist ratio) the enzyme activity drops off at too great a rate to be accounted for in terms of improved enzyme stability during a reasonable length mash. In one study total extract from PA malt dropped to 70% of the control value, when thickness was increased to a 0.5qt/lb for a 60 minute, 65C mash. At 1qt/lb it was up to 96%, at 1.5 qt/lb about 98+%, and essentially 100% at 2qt/lb. So 1/qt/lb is a reasonable lower bound for all malt mashes. The paper also studied mashes with 50% wheat, corn and potato starch added. All, but especially the corn and potato starches benefited greatly from thinner mashes above 1.5 qt/lb. The same source shows that extract dropped by about 15% while mashing 1.25 qt/lb *WHEN* a 10P(10%) sugar solution was used. The sugar inhibits some of the enzymes, stabilizes some and traps water molecules. A comparable (10%) addition of pentosans, and betaglucans caused about a 25% loss in an artificial starch+enzyme mash. In another paper (JIB, v97, pp85) fermentability for a 70C, 1hr mash over a huge range of thickness [0.5qt/lb to 3.5qt/lb] varied by about +-8%, while bumping the temperature to 75C caused a 21% to 52% drop depending on thinness. >What I do is start with a thick mash to increase >the concentration of the proteases and stage It isn't the concentration of the proteases that makes a difference - it's the lack of water that improves stability enough without dropping activity too much. =========== The notes below refer generally to the enzyme class but not to barley enzymes specifically. Barley contains several different alpha- and beta- amylases isozymes. From Verlag Press 'Enzyme Handbook' Alpha-amylase: Inhibitors: Hg+, Cu+, Mg+, Ca++, Fe3+, Zn++, Al3+, Ni++, salts of the above metals, iodoacetate, ascorbic acid, wheat alpha-amylase inhibitor protein, maltotritol, panitol, maltose [non-competitive]. Cofactors: Histidine, dithiothreitol, mercaptoethanol Metal Compounds/Salts: Ca++ (requirement for some isozymes, not others), Cl- (requirement for maximal activity), Ba++ (stimulating effect), Fe++ (enhance activity), Phosphate (stimulating effect), Anions (activating), Zn++ (activation) Stability Info: Ca++ - protects against proteolysis, thermal inactivation Urea - no denaturing, Guanidine hydrochloride - denaturing Starch, & enzyme products - stabilizing, prevents heat denaturing. Na+ - stabilizer, resistance to proteolysis. Carbohydrates, Polyols[sugar alcohols] - stabilizers. - -- Beta-Amylase: Inhibitors: Glucose, Maltose(competitive inhibition), alpha-methyl- glucosidase, cyclodextrins, Ag+, Hg++, Cu++, Ni++, Fe3+, Mn++, Mg++, CO2- (!!), bacterial beta-amylase inhibitor protein. EDTA, Zn++, salts of the metals above. CoFactors: none Metal Compounds/Salts: no metal req for some, K+ - reactivity enhancement, Na+ - reactivity enhancement, Ca+ - reactivity enhancement. General Stability Info: Ca++ - stabilizing Freezing - partial denaturation, dilution - destabilizing [the dilution issue may indicate that beta-amylase is self- stabilizing, diluting thus decreases the concentration of the BA stabilizer. - -- -S Return to table of contents
Date: Tue, 4 May 1999 14:55:08 -0700 From: "Sandlin, Jonathan Mark - BUS" <SANJM304 at bus.orst.edu> Subject: food grade, fast drying, heat tolerant sealant? I am planning to use one of my boiling pots for a fermenter. I like the idea of being able to steam sanitize it. I would like to find some way to seal the lid onto the top of my converted keg. I plan to drill two holes in the top of the lid for filling and gas releif. Any ideas on how I can seal the lid on? Thank you in advance for your help! Jon Sandlin Corvallis, OR 97330 Return to table of contents
Date: Tue, 4 May 1999 18:36:06 -0700 From: "Fred Waltman" <fwaltman at mediaone.net> Subject: Tomahawk Hops Brewinales asks about Tomahawk hops: I believe Tomahawk is one broker's (Yakima Chief?) trademark/name for Columbus. Fred Waltman Culver City Home Brewing Supply (LA Area) www.brewsupply.com *and* www.LABeer.com Return to table of contents
Date: Tue, 04 May 1999 20:03:45 From: william macher <macher at telerama.lm.com> Subject: A little N2/CO2 foam decay measurement... Hi All, Since I have a tank of Nitrogen (not a CO2/N2 mix) and a CO2 tank, I decided to try a little test to see if there would be noticeable difference in the rate of collapse of the head of glass of beer comprised of CO2 bubbles, as compared to a head of mainly N2 bubbles. I used a 20-ounce English-pub-style glass, and a can of Iron City Light beer. I first poured the 2 inches of beer into the glass. After the head collapsed I marked the level, inserted a .5 x 1.0 inch airstone and bubbled N2 into the beer until the foam filled the glass to the rim. Nearly all the beer was turned to foam in order to fill the glass. The airstone was removed. I started my stop watch at that point and timed the decay of the foam. After 10 minutes, the N2 foam was about half gone as far as height goes, but there were areas under the top of the foam that showed more decay than others. Perhaps this is because of the foam was actually a combination of N2 and CO2, the result of my starting with carbonated beer. I dumped the glass at this point, rinsed it with cold water, and refilled it with 2 inches of I.C. Light, let the head collapse and repeated the above procedure. After 2.5 minutes elapsed, the CO2 foam had collapsed to about the same level that the N2 foam had been at after 10 minutes. After 6.5 minutes the clear surface of the beer began to show. At minute 10, about 60 percent of the beer surface was clear, and only about one or two tablespoons of foam remained. So indications are that N2 bubbles do indeed decay at a slower rate than C02 bubbles... I know this has been said many times...somehow the debate on bubble tensions and differential pressures and such left the question unanswered in my mind...so now we have a crude measurement that indicates this is indeed the case. For whatever that is worth... And no, I do not drink I.C. Light. I keep it on hand for my non-beer-drinking friends...:-) Bill Bill Macher Pittsburgh, PA USA Bill Macher macher at telerama.lm.com Pittsburgh, PA USA Return to table of contents
Date: Tue, 04 May 1999 22:54:30 -0400 From: John Herman <johnvic at earthlink.net> Subject: Listermann Is there an email address for Listermann products? - -- \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ * Bicycling, Bassing and Brewing * * * * The Real 3 B's! * * * * John Herman * * johnvic at earthlink.net * ////////////////////////////////// Return to table of contents
Date: Tue, 4 May 1999 23:53:11 EDT From: ThomasM923 at aol.com Subject: Signed, Sticky Armpits Jeff Beinhaur wrote in HBD# 3021: "...confidently place the fill tube from the pot into the carboy opened the valve and a strong flow began. Problem is that lasted about 5 seconds and then nothing. With all of the hops and I assume break material the SureScreen was clogged.My last resort is the old "hairy arm" technique to keep the screen from clogging..." My suggestion is to use an NHU (non-hairy utensil) instead of your arm (seems like a lot of people are sticking their arms into otherwise sterile wort these days---geesh). I scrape the assorted gunk off the screen with my brewing spoon. Of course a big winking smiley face goes right about here ---> Thomas Murray Maplewood, NJ Return to table of contents
Date: Wed, 5 May 1999 00:55:13 -0500 From: "Rob Moline" <brewer at isunet.net> Subject: The Jethro Gump Report The Jethro Gump Report Nitrogenation at the recent CraftBrewers Conference in Phoenix, Matt Brynilson presented his paper, "Nitrogenation- Practical Nitro-Brew Production." With his permission, I am going to detail the hand-out that he distributed. Perhaps later, I will scan it and place it on the Web, so that you will be able to see the graphs, we'll see. The audio tape recording of the discussion is available from Tree Farm Tapes, http://www.treefarmtapes.com/catalog/conference.asp?conferenceid=585 or (800)-468-0464. Tapes sell for 9$US, plus 2$US S&H. Matt has also graciously agreed to discuss this with you, and you may contact him at mbryndil at gooseisland.com In the following any comments in < > are my own words from my memory of the discussion, and should not be construed as Mr. Brynildson's. "Nitrogenation Defined - Solubilization of nitrogen gas into beer in the presence of CO2 and the stabilization of that solution until dispense. - Modern Method of Cask Style draft and Dispense. - A successful nitrogenation program extends all the way to the glass. Enhanced Drinkability - Visually stimulating dispense - "Theater Of Pour" - Increased Head Retention - Rounder, smoother mouthfeel - Less carbonation Background - Arthur Guinness Ltd., the father of Nitrogenated beers. - Was discovered through experimentation with early pressurized dispense. (1950's) - American publicans use mixed gas to stabilize carbonated products. <For example, in a long line draft system; one that needs a lot of pressure such as in overcoming a high static head--like when the kegs are in the cellar and the draft towers are upstairs; or in any system where the product is not served in a rapid fashion. This is to prevent increasing saturation of the beer with CO2 from the pressurization need to drive the product, not to nitrogenate the beer.> Recognized Products Product CO2 N2 Smooth 1.2 v/v 20-24 ppm at 48F (2400ppm) Super Smooth 1.0 v/v 35-40 ppm at 48F (2000ppm) Hybrid 1.0-1.2 v/v 35 ppm + at 38-45F (2000-2400) Physical Properties GAS Dissolution Coefficient Atomic Weight CO2 1.405 44.011 N2 0.020 28.01 - Nitrogen 70% less soluble than CO2. - Nitrogen 78% of the air we breathe. Relative Units Chart <Here follows a chart that demonstrates the proportions of CO2 and N2 in blended gas beers vs Normally CO2'd beers....> Henry's Law - P = kC -Concentration of dissolved gas is proprtional to the partial pressure of the gas phase. - Dissolution constant is temperature dependent. (Chart) Dalton's Law - P(system) = P1 + P2 + P3 - Total system pressure is equal to the sum of the partial pressure. - Independent equilibrium is established betweem the gas and liquid phase for each gas HEAD SPACE P-CO2 P-N2 /| | /| | | | | | | | | | _____________|_|_____________________|_|___________ | | | | | | | | | | | | | |/ | |/ D-CO2 D-N2 AQUEOUS PHASE Applicable Gas Law Rules - Solubility is Pressure dependent - Solubility is Temperature dependent - Solubility of each gas is independent of the partial pressures of other gases in the system. So That... - CO2 cannot be held in aqueous solution with N2 head pressure. - N2 cannot be held in aqueous solution with CO2 head pressure. - Mixed gas must be used for stabilization to lock in the equilibrium we want to establish. Foam Physics - Foam Formation..............Increased by N2 gas breakout. - Drainage....................Exaggerated (surge)<cascade> - Coalescense.................Slowed by N2/Air equilibrium - Disproportion...............Slowed by N2/Air equilibrium Natural Foam Enhancement - Mashing to Malt Analysis - All Malt Beers - Wheat - Hop Extracts (Hexa-Hydro-co-Humulone) - Dry Hops - Raw Barley - Oatmeal Foam Depth Control - Target D-N2 levels should be above 25 ppm (prefer 35 ppm+) - D-CO2 levels can then be used to adjust the foam depth. - Higher D-N2 levels require lower D-CO2 to obtain satisfactory foam depth. - Individual brewery must decide on the "proper pour." This is not the end of Mr. Brynildson's paper, but the rest focuses on the practical, and safety oriented issues involved. But a read of recent HBD's displays lots of discussion, so I will add my .02 again to a few of them... 1) I can confirm that the nitrogen is not mixed into the solution at dispense. It comes out of solution upon dispense. 2) There is no gas in the widget before the tin is filled with product. It is empty, with a 0.6 mm hole laser drilled into it. The dosing of liquid N2 forces liquid, CO2 and N2 in. 3) There is no dual dip tube in a Guinness keg, simply the same beer out tube from the bottom of the keg, and a gas in port in the body of the valve at the top of the keg. 4) Nathaniel Lansing hits the nail on the head in his discussion of gasses not popping out of solution instantly....the holes in the sparkler/creamer plate in a Guinness style faucet 'shear' the gasses out of solution. And gee, they look to be...oh, well, I'd say they look about...ah, could it be??....0.6 mm????? But I do have a place in my head, as unscientific as it is that sez that the N2 would leave, without the sparkler, more rapidly than CO2, purely a guess. After all you gotta work so much harder to get it in, so it just seems obvious to me that when you remove the stabilizing partial pressure of N2 in the head space. Anyhoo, that's it for me on Nitrogen. I do want to say thanks to the folks at the CraftBrewers Convention, especially Dave Edgar for throwing a great event, and to Brian Rezac for his ongoing work for Big Brew 99. It was a blast to be linked to others around the world for the Toast, even though we couldn't brew there. Cheers! Jethro Gump Rob Moline brewer at isunet.net Lallemand Web Site jethro at isunet.net "The More I Know About Beer, The More I Realize I Need To Know More About Beer!" Return to table of contents
Date: Wed, 05 May 1999 02:25:17 -0500 From: ensmingr at npac.syr.edu Subject: clear Weizen Fred L. Johnson wrote about his clear homebrewed Weizenbier in HBD 3022-12 http://www.hbd.org/hbd/archive/3022.html#3022-12 . It is a common misconception that Hefe Weizenbier *must* be cloudy to be true to style. I lived in Germany for about 2 years and consumed many different commercial Weizenbiers, some brewed in the very town where I lived, others brewed elsewhere in Germany. All bottled versions were clear if poured carefully from the bottle into the glass; in other words, there is no evident protein haze or yeast haze. However, it is common practice to pour a bottle of Weizenbier into the glass with great flourish so that the yeast at the bottom is suspended, giving the beer a very evident yeast haze. Cheers! Peter A. Ensminger Syracuse, NY P.S. Fred - I really love Weizenbier ... can I stop by for one next time I'm in Apex, North Carolina? Return to table of contents
Date: Wed, 5 May 1999 03:12:36 CSTCDT From: "Anthony & Julie Brown" <brown32 at web1.ecol.net> Subject: re: clear hefeweizens Here's my limited but similar experience with this subject... I have brewed a few wheat beers with #3068 myself, using 65% wheat extract and all have turned out clearer than some non wheat beers I have brewed. I thought this odd myself, hoping to encounter a traditionaly cloudy brew. I have just finished an apricot wheat with the same 65% wheat extract but tried the wyeast Irish Ale yeast(they were out of any bavarian yeasts or american "chico") and it turned out wonderfully cloudy with no signs of clearing and now it it's second week in the keg. I haven't given much thought to why, but have been blaming it on the yeast strains since I used the same extract in each brew. At least you are not alone in your experience... Tony B. Return to table of contents
Date: Wed, 5 May 1999 10:21:36 +0100 From: "Rob Compton" <Compton at btinternet.com> Subject: Guinness Heads Hello from good old Blighty! I asked the landlord of my local pub (some 100 yards the other side of the road), what he uses to propel the liquid genius from it's barrel. As with all of his kegged beer, it's "powered" by the same CO2 manifold system as usual. No Nitrogen here! I've tried brewing Guinness style beers in the past, and have copied the bottled styles quite successfully, but can't get the head right on the draught style. I use the right malt, the right hops, and what's more the genuine article flaked barley ("found" at one of the own maltings!!), water treatment is OK, sanitation is fine, etc... but no creamy head, not that lasts very long. I think I boiled my last batch for too long as it's head retention is poor, but it tastes fine, so what the heck! I have found that running higher pressure for delivery, and a smaller nozzle in the tap makes a lot of difference. Proper pub beer fonts have their own pressure regulators at the tap. I have a couple that need installing in the house (right next to the arm chair!), so I'll see what happens when I use one. I usually deliver the beer at around 10psi, compared to around 5 for ordinary ales, wheat beers & lagers. Happy brewing. Rob. Return to table of contents
Date: Wed, 5 May 1999 07:03:00 -0400 From: "Rhode, Timothy J (IndSys, SalemVA)" <Timothy.Rhode at indsys.ge.com> Subject: Flux removal I am in the process of building a RIMS and working on the keg plumbing. I've been sweating copper piping/fittings using lead free solder. I've also been using flux to make the job easier. Does anyone know what I need to do to get rid of the extra flux? Tim Rhode timothy.rhode at indsys.ge.com Return to table of contents
Date: Wed, 5 May 1999 08:24:31 EDT From: MicahM1269 at aol.com Subject: cleaning crowns >Rob recently posted: >"I'm wondering if anyone has asked a micro or a major on how they clean >theirs. I have askedand this 1 (one) micro said that they didn't. They dump >them right out ofthe freshly opened box and cap them without cleaning any of >them." I have worked at various breweries, large and small over the last 10 years. I have never seen any packaging operation clean or try to sanitize crowns (bottles) or ends(cans) or caps(screw off). Nor have I heard or read about any contamiation or spoilage that has been attributed to the above mentioned closures. IMHO the risk of damaging or compromising the crown as a result of boiling or chemical cleaning is far greater than the risk of spoilage from the crown itself. micah millspaw - brewer at large Return to table of contents
Date: Wed, 5 May 1999 09:37:59 -0400 From: "David Kerr" <dkerr at semc.org> Subject: re: Ring Around the Porter Patrick writes: >After bottling a recent batch of Papzian's Silver Dollar Porter I noticed a >small ring around the bottle neck at the top of the liquid level. The beer >came out nicely as far as my buds can detect, but I thought that I >remembered reading this was a sign of infection. I looked in Miller's book >and he lists two possible causes: infection and break formation. I seem to recall a comment a year or so back that using DME to prime can cause this. Dave Kerr - Needham, MA Return to table of contents
Date: Wed, 5 May 1999 07:02:26 -0700 (PDT) From: Steve Jackson <stvjackson at yahoo.com> Subject: Re: AOB Tax Designation Change In HBD #3022 (May 5, 1999), Paul Gatza writes: >>>> <snip> Although we have done limited lobbying in the past, the new status allows us to lobby without restriction. July 1 is not only the day of our new tax status, it is also the effective date for legalized homebrewing in Idaho. As of this writing, the states of Alabama, Iowa, Kentucky, Mississippi, Ohio, Oklahoma and Utah still prohibit homebrewing. We can take a more active role in these states as our budget allows if our involvement is requested by AHA members who volunteer to lead the effort to legalize homebrewing in these states. This change gives us the ability to fight against a potential neo-prohibitionist against the freedom to homebrew legally that most of us enjoy. <<<< Before the AHA sets its sights on lobbying and such, perhaps it should pay more attention to providing the basic assistance for homebrewing legal efforts that it currently promises but consistently fails to deliver. Thanks to the efforts of several dedicated Indiana homebrewers (and in spite of the AHA's failure to provide even basic assistance), as of July 1 several changes will be made to state law regarding homebrewing. While it has long been legal to make homebrew in Indiana a strict, literal reading of the law made it illegal to take any of the beer out of one's home. As a result, competitions were not legal, and technically homebrew club meetings were illegal as well. A friend of mine was even threatened with arrest for "bootlegging" if he handed out samples of homebrew at a class. As of July 1, state law will allow the removal of homemade beer and wine for purposes of education, evaluation, etc. This will make competitions legal and possible, and put the stamp of legality on club meetings. The new law will also allow brewpubs, bars, etc. to host club meetings without risking the loss of their license. And no worries about bootlegging indictments, either. This is the result of three years' worth of effort by several homebrewers and one dedicated legislator (for all you Indiana folks reading this, drop a note of thanks to State Rep. Brian Hasler from Evansville). During each of the three sessions that this legislation has been considered, we have requested some assistance from the AHA. During each of three sessions, we have received little or no assistance or support. The most we ever received was a generic fact sheet about homebrewing in the U.S. No Indiana-specific information, no mailings sent out to Indiana AHA members to alert them of the pending changes, nothing. This despite several notifications to AHA folks, including Paul Gatza. This is pretty basic stuff, and it's what the AHA is already supposed to be doing, according to its promotional materials (if I recall correctly, the folks in Idaho received the same minimal response from the AHA in their legalization efforts). If the AHA can't handle simple tasks such as this, I'd hate to see how badly it would bungle organized lobbying efforts. I have no reason to doubt Paul Gatza's sincerity when he says he is trying to make the AHA more responsive to members' needs (for the record, I am not a member, but the lead person in the legalization effort is, and our local club is AHA-affiliated). However, the AHA should stop thinking about what it might be able to do in terms of expanded efforts when it can't even get its current core duties done properly. -Steve in Indianapolis _________________________________________________________ Do You Yahoo!? Get your free at yahoo.com address at http://mail.yahoo.com Return to table of contents
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