HOMEBREW Digest #2640 Wed 18 February 1998

[Prev HBD] [Index] [Next HBD] [Back]

		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

  Roasting Barley / RIMS on Glue / Mixing Motor / Hot Plate (Kyle Druey)
  Mash efficiency (Michael Satterwhite)
  Home Brewery / Brewcrafters (Dave Williams)
  Matthews Java Program (Brad McMahon)
  Re: Mash Efficiency/Extract Brewing ("Charles L. Ehlers")
  Mini kegs (JGORMAN)
  Mail Order Companies "Michael E. Dingas" 2/17/98 (Vachom)
  Bluebonnet Brew-Off -- any HBD folk coming? (Samuel Mize)
  Palexperiment (John Varady)
  Re: Indoor Propane Use (Steve Scott)
  RE: Osmotic Presssure ("Dustin H. Norlund")
  RE: Mash efficiency (for extract brewers) (David Conger)
  Recipe Efficiency (KennyEddy)
  Questions and problems with EasyMasher resolved (Danny Breidenbach)
  indoor propane use ("Jesse Benbow")
  floating sediment (Bob McDonald)
  Why a duck? (David Kerr)
  Osmosis/Chloramine/Propane (AJ)
  Weissbier 4VG ("Hubert Hanghofer")
  Fluid dynamics (Al Korzonas)
  Diacetyl (George_De_Piro)
  EM Flow (Jack Schmidling)
  irish moss (IM) (Andy Walsh)
  Re: Mash Efficiency (irajay)
  Propane and Frederick Wills (AlannnnT)

NOTE NEW HOMEBREW ADDRESS: hbd.org Send articles for __publication_only__ to post@hbd.org (Articles are published in the order they are received.) 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! For "Cat's Meow" information, send mail to brewery at hbd.org Homebrew Digest Information on the Web: http://hbd.org Requests for back issues will be ignored. Back issues are available via: 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 JANITORS on duty: Pat Babcock and Karl Lutzen (janitor@hbd.org)
---------------------------------------------------------------------- Date: Mon, 16 Feb 1998 13:10:31 -0800 From: Kyle Druey <druey at ibm.net> Subject: Roasting Barley / RIMS on Glue / Mixing Motor / Hot Plate Roasting Barley Warning! If you are going to roast barley at home take Dave Burley's advice and don't do it when the SO is in the house, and watch it closely. >Maybe we can cajole another HBDer who related his recent classic black >malt roasting experiences to me, to share them with the collective. I am the cajolee Dave is referring to. I asked Dave to give me some guidelines on how to roast barley at home. In particular, I wanted to roast oatmeal for a roasted oatmeal stout (Dave, email me your snail mail address so I can send you a bottle, it turned out very yummy - rich and hardy). He kindly sent me instructions, and explicitly told me only to do it only when the wife was out of the house, and to watch the barley like a hawk near the end of roasting. I waited for an opportune time to do my roasting, and had waited several weeks. My wife likes to work part time a few days per week, and on those days I pick the kids up at a friends house after work. So it was on one of these days that I got the kids and realized this was my opportunity because the wife would not be home for another hour. I came home, set Junior up with his favorite video, the Lion King, and threw him a box of Cheerios to munch on. I then turned the oven on to 400 F set on 'bake', put 1# of oatmeal on a cookie sheet, and closed the oven door. After 10' nothing is happening, heat was is in the oven, but the oatmeal looked the same color, so I decided to turn the oven on 'broil'. I thought that this was going to be so simple that I deciced I could feed my 6 month old daughter her bottle and roast this oatmeal at the same time. A piece of cake, right? After 20' only a slight stream of smoke is coming out of the oven, I pull the pan out, stir the oatmeal a little, then put it back in and resume feeding Jessica. After 30' a little more smoke is coming out but no big deal. I then turn up the oven to 500 F for the 'roastout', thinking it would be done in about 5 or 10 minutes. I close the door, turn my back to continue feeding the baby, and then I start to smell smoke. I turn around and see a camp fire blazing away in my oven with billows of smoke just spewing out, and all I can think of is that Dave told me to 'watch it like a hawk'! I put the baby down on the floor in the other room, threw open the oven door, and began spraying the fire with water using a spray bottle. When the flames were out I put the cookie sheet outside, and opened a few doors and windows and turned on the ceiling fans. So here I am: the living room and kitchen are filled with smoke, the baby is screaming her head off on the floor, Junior is having the time of his life and is jumping up and down swinging his plastic baseball bat at the thick smoke, all the doors and windows are wide open and it is 40 F outside, the somke alarm is starting to go on and off intermittently, the neighbors are starting to peak out their front doors to see what the hell is going on, and my wife gets home in 10 minutes! After a few minutes of this chaos I got the smoke alarm to quiet down, I calmed down my baby daughter, and got Junior back on track with his video. By the time my wife got home the smoke had cleared out pretty good and all she had to say was "Honey, are you making popcorn?". Roasting at home is well worth your time and effort, but you must be careful! ***************************************** RIMS on Glue I wanted to pass this along to anyone who is preparing to fabricate a RIMS. Use epoxy, don't solder. The glue is so easy, took me about 10' to glue my second generation heat chamber and manifolding a few months ago. I bought some stuff called "Copper Bond" at Home Depot. It is a 2 part epoxy that is made specifically for copper water pipes. It is supposedly rated for 200 psi at 200 F, and is nontoxic. I hope it doesn't turn out too good to be true! I like it so far. ****************************************** HLT Mixing Motor Can someone please advise me on where I can purchase a motor. The motor will be used to drive a stir blade for an HLT. It needs to turn at about 30 rpm. I am going to mount an electric heating element onto a 5 gallon Gott cooler, and mount the stirring motor on top of the lid. I built it without the stirrer, but there is a significant amount of heat stratification, and the water must be stirred periodically to get a decent temp reading. The stirrer will also come in handy when I acidify the sparge water. No more stirring the sparge water! ******************************************* Hot Plate Last bit of wasted bandwidth. I will probably get flamed (no pun intended) on this one, but I have not read about this yet and it might be a good option for somebody. I just built a small heat plate to boil my wort. I was slowly destroying my kitchen stove and I needed to do something about it. I opted for the hot plate instead of a gas burner for several reasons that I don't want to get into now. The hot plate has four smallish electric burners on it, that all can be controlled individually (120V). The burner footprint is such that my 10 gal aluminum pot fits perfectly over it (we can get into the use of aluminum later, but for now lets just say that advocating the stainless steel pot is a homebrew shop conspiracy and they don't want to let the Al secret out!). The hot plate produces just enough heat output to have 6 gallons of wort boiling by the end of a 30-45 minute sparge (the sparge collects in the boiler as the heat is applied). I can stay indoors with this setup and don't have to mess with propane. Just some info for ya'll to use and abuse. Happy RIMsing, Infusing, Extracting, Stirring, etc. Sorry for chewing up so may kilobytes in the queue, but from the size of the queue lately it looks like many HBDers are hibernating for the winter. Kyle Druey Bakersfield, CA Return to table of contents
Date: Tue, 17 Feb 1998 06:11:10 -0600 From: Michael Satterwhite <satterwh at weblore.com> Subject: Mash efficiency >Date: Mon, 16 Feb 1998 17:10:53 -0500 >From: ricjohnson at SURRY.NET >Subject: Mash efficiency > >I am an extract brewer. Recently I have been evaluating some brewing >software. All the computations require mash efficiency. What should an >extract brewer enter for this? I've been using the Brewers Workshop for about a year and am also an extract brewer. Although some of the more experienced types here may correct me, I don't think this is that big a deal with extract specialty grains. It really only applies to the grains you're using. As an extract brewer, the specialty grains aren't there to contribute gravity. As a result, I left the mash efficiency setting at the software's default. I probably should have lowered it to nearly nothing for more accuracy. "Congress shall make no law...abridging the freedom of speech" http://www.weblore.com/soapbox Return to table of contents
Date: Tue, 17 Feb 1998 07:27:40 -0500 From: rdavis at gator.net (Dave Williams) Subject: Home Brewery / Brewcrafters "Michael E. Dingas" <dingasm at worldnet.att.net> writes in HBD #2639: >Like most, I'm always looking for ways to cut my costs. The >obvious choice was to try ordering supplies mailorder. Mike, I live in North Florida and there's no HB shop nearby so I get all of my supplies mail order. >The company I chose was The Home Brewery. The Florida location >never replied. The most likely reason that the Florida store didn't reply is that they recently went out of business. The stated reason was that they didn't have enough local business to keep them going in a dwindling mail order market. Can't say why the Kentucky location didn't respond. >Has anyone dealt with HB and what kind of service did you get? >With so much shady dealings on the Internet, I don't understand >why I'm having so much trouble getting a civil reply out of them. When the Florida store was open, I recieved good service and the prices were good. With other locations, YMMV. If you're looking for a dependable mail order source with good pricing, I highly recommend Brewcrafters, located in Bradenton, Florida (www.brewcrafters.com, catalog online) It's run by Jim Antonino who is a knowledgeable brewer. Jim has also been very flexible. He once had a 55 lb bag of German Pilsner malt drop shipped directly to me from his suplier in Atlanta to reduce freight costs. On the rare occasions that there have been problems with orders (usually UPS's fault), Jim has worked diligently to correct them quickly. Although I have no affiliation, I do recommend Brewcrafters for selfish reasons. If Jim's mail order business thrives, He'll be less likely to go the way of the Home Brewery store and more likely to keep prices low. Since I have no local HB store, Brewcrafters *is* my local HB store. So, please support *my* local HB store! Cheers, Dave Williams Newberry, Florida Return to table of contents
Date: Tue, 17 Feb 1998 23:13:16 +1000 From: Brad McMahon <brad at sa.apana.org.au> Subject: Matthews Java Program Matthew Arnold wrote: >Currently it only uses standard measurements (quarts, pounds, degrees >Fahrenheit). Once I figure a few things out, I will update it so you >can choose standard or metric figures. ARGH! Metric IS standard. It would be too much to ask Americans to come out of the 18th century before the 21st century arrives, wouldn't it :-) - -- Brad McMahon Adelaide, South Australia brad at sa.apana.org.au PGP Return to table of contents
Date: Tue, 17 Feb 1998 07:05:02 -0600 From: "Charles L. Ehlers" <clehlers at flinthills.com> Subject: Re: Mash Efficiency/Extract Brewing <<Date: Mon, 16 Feb 1998 17:10:53 -0500 From: ricjohnson at SURRY.NET Subject: Mash efficiency I am an extract brewer. Recently I have been evaluating some brewing software. All the computations require mash efficiency. What should an extract brewer enter for this?>> Check out the Brewers' Calculator. Sole distributor is Hop Tech, http://www.hoptech.com. $39.95, no shipping if mailed w/in the US. Not affiliated w/ Hop Tech, makers of Brewers' Calc, etc., etc., etc. I just played w/ the Brewers' Calc and like what it'll help me do w/ extract now, and later w/ all grain. Return to table of contents
Date: 17 Feb 1998 08:29:53 -0500 From: JGORMAN at steelcase.com Subject: Mini kegs I am thinking about getting to kegging using 5 liter kegs with the CO2 taps. A fellow brewster mentioned that they are somewhat unreliable. Is there anyone out there that has experience with these? Jason Gorman jgorman at steelcase.com River Dog Brewery Return to table of contents
Date: Tue, 17 Feb 1998 08:01:44 -0600 From: Vachom <MVachow at newman.k12.la.us> Subject: Mail Order Companies "Michael E. Dingas" 2/17/98 Texas isn't next door to Georgia, but I can assure you that if you contact St. Patrick's of Austin--a homebrew supply store that does a healthy mail order business--you'll get prompt service. I am in no way affiliated with this organization; this is just an honest testimonial. St. Pat's has a web site where you can sign up for a catalog which will arrive promptly, and the people there will be glad to help you out with anything you need. The beauty of the web--for entrepreneurs--is that you can design a page at relatively low cost that will make your little backwater, podunk, ill-conceived, lackadaisical business appear to be an all-world operation. I wouldn't waste any more time on the FL operation. I teach at a prep school where we have increasing numbers of kids who have learned somewhere to write C++, JAVA, HTML, VRML and are already making lots of money in their spare time designing web pages because they can undersell the incorporated, "adult" businesses big time; many are beginning to question seriously the use of going to college where the computer department will most likely be a year behind the cutting edge of the industry anyway. About saving costs: I've found that the only real way to save costs is to buy base malt in 50lb. bags. Your local supply shop owner gets his biggest mark-up on selling you bulk grains in the quantities you need for one batch, an even bigger mark-up if you buy the stuff as a "kit." The catch with buying base malt in greater quantities is that you need to use it up relatively efficiently. Return to table of contents
Date: Tue, 17 Feb 1998 08:42:02 -0600 (CST) From: Samuel Mize <smize at prime.imagin.net> Subject: Bluebonnet Brew-Off -- any HBD folk coming? Greetings, The Bluebonnet Brew-Off is coming up in Dallas, March 20-22, web page http://hbd.org/users/kobb/blue.htm. I'd like to know who's planning to attend. Perhaps we can get together on Saturday or Sunday. If you're coming and interested, please reply by email -- I'll coordinate and make an announcement on HBD. Best, Sam Mize - -- Samuel Mize -- smize at imagin.net -- Team Ada Fight Spam - see http://www.cauce.org/ Personal net account - die gedanken sind frei Return to table of contents
Date: Tue, 17 Feb 1998 09:54:41 -0800 From: John Varady <rust1d at li.com> Subject: Palexperiment Randy Ricchi comments: >I see one problem with John Varady's proposal for a pale ale experiment >(2/16/98 HBD): not everyone get's the same extraction efficiency. Michel Brown states: > Also, I'm still troubled by the hop bill -- I keep > coming up with 63 IBU's acording to Tinseth's formulary :-/ Great for an > IPA, not so good for an OPA (Oregon Pale Ale which is traditionally 75% These are two things that will make the experiment interesting. The differences in extract and utilization will be one of the data points to track. Louis Bonham has offered to do spectrophotometric IBU measurements on a few of the beers (as well as a write up in his BT column), which will enable us to see the utilization percentages achieved by burner styles. For those curious, I used a hop utilization of 21% for a 75 minute boil. These numbers come from somewhere on the net, and are based on Jackie Ragers calculations. Some people believe that they get 30% for a 60 minute boil, but IMO, i've found this to be way high. This experiment should put that to the test. P.S. - I think we have all the brewers we need, so sit back and watch if you are interested. John Varady http://www.netaxs.com/~vectorsys/varady Boneyard Brewing The HomeBrew Recipe Calculating Program Glenside, PA rust1d at usa.net Return to table of contents
Date: Tue, 17 Feb 1998 10:05:34 -0500 From: sscott at lightlink.com (Steve Scott) Subject: Re: Indoor Propane Use "Wills, Frederick J" asks >If this is such a dangerous situation, why do many people have bottled >LP gas (propane) delivered in large bottles or to tanks that remain >outdoors but the gas is then run into the house to fuel furnaces, cook >stoves and ovens as well as water heaters? Wouldn't any of these >appliances be just as likely to malfunction with the same end result? >These appliances, unlike the typical homebrew burner, are usually left >unattended and would seem to present an even bigger hazard in that >regard. These devices have safety shut offs. If the pilot goes out the gas valve will not allow the flow of gas into the appliance. With new furnaces/boilers if there is a flameout the gas valve will shut down in under 1 second. My concern (BTW, I'm a licensed heating contractor) is not leaks per se but rather a flameout while I run to the bathroom, get ingredients or am away from the burner for a few minutes. Stove top burners don't have safety shut offs but they generally run about 7,000 but/hr instead of the 100,000 or btu/hr of most brew pot burners. >I would think that the biggest chance for leakage would occur at the >appliance, not from the gas bottle. Perhaps this is my >misunderstanding. Would running a hard gas line from a bottle outside >to a homebrew burner used indoor be less risky? Soemwhat. It is against NFPA code (and probably most local codes) to store propane tanks indoors. >Also, why wouldn't Natural Gas which is lighter than air tend to pool-up >at ceiling level and present the same hazard in reverse? Especially in >winter months when houses are closed up tight and these heating >appliances are typically in use? Most sources of ignition, water heaters, furnaces, boilers, are close to the floor. However, there a quite a few reports every year of houses or other buildings being rocked off their foundations due to gas (methane or propane) leaks. Personally, there is NO way that I will put a gas burner the size that we use in the house that contains my wife and children if it doesn't have some sort of safety shut off. I brew outdoors (upstate New York) year round under a tarp. Return to table of contents
Date: Tue, 17 Feb 1998 08:58:27 -0600 From: "Dustin H. Norlund" <dustin at minibrew.com> Subject: RE: Osmotic Presssure >"David R. Burley" <Dave_Burley at compuserve.com> wrote: >Osmotic force requires a semi-permeable membrane across which this pressure can >be developed. To my knowledge the significantly greater ( if any at all) part >of the wort is not held back by a semi-permeable membrane. What? The whole process involves a semi-permeable membrane. This membrane is the edges of the cracked grain. There is a high concentration of sugars (the internal grain structure) etc on one side and a low concentration (the wort) on the other side. If this does not meet your guidelines for osmosis and therefore have some osmotic force behind it please explain. BTW I am an engineer. No more wise cracks... ehhehhheeh > Sparging is a diffusion and rinsing driven engine and the most efficient >method is to have high concentration sugar diffuse into pure water. Return to table of contents
Date: Tue, 17 Feb 1998 10:16:48 -0500 From: David Conger <dconger at roadshow.com> Subject: RE: Mash efficiency (for extract brewers) In HBD #2639, Ric Johnson asks what an extract brewer should enter for mash efficiency in brewing software. This is a problem area for most of the brewing software I've seen. Reconstituting malt extract should be calculated as 100% efficient. The efficiency of steeping specialty grains is quite low, however. I've read that 40% is a reasonable guess for steeped specialty grains. On piece of software which handles this problem correctly is the Recipator (http://hbd.org/recipator/). - David Conger Return to table of contents
Date: Tue, 17 Feb 1998 10:37:31 EST From: KennyEddy at aol.com Subject: Recipe Efficiency ricjohnson asks about setting a figure for efficiency in recipe formulation software when extract brewing. This can be a tricky subject for some programs such as SUDS 4. Even when simply steeping the grains, SUDS will figure the gravity contribution as if you are mashing, and uses the efficiency figure in this calcualtion. Extraction from steeping will differ greatly from extraction when mashing in most cases. Note that the efficiency figure has no impact on gravity contribution from extract and other sugars like honey or corn syrup (there's a checkbox for each malt/sugar item that determines this). One thing you can do is to set the efficiency to say 50% to account for this. Another approach would be to use an efficiency of 100% but add malt choices that have realistic extraction figures (see AlK's new book for data on this; I think one of the brewing rags has info in a recent issue as well). Thus you can select "Crystal 40 - Steeped" at say 1.019 instead of the stock "Crystal 40" selection with a 1.032 figure used for mashed crystal. Message to all recipe formulation software authors: allow each malt to be entered with its own extract potential and efficiency, rather than using a global figure like SUDS does. ***** Ken Schwartz El Paso, TX KennyEddy at aol.com http://members.aol.com/kennyeddy Return to table of contents
Date: Tue, 17 Feb 1998 10:39:53 -0500 From: Danny Breidenbach <DBreidenbach at nctm.org> Subject: Questions and problems with EasyMasher resolved To Jack and everyone else: I posted some "Musings and Questions about my first use of EasyMasher" in HBD 2633. My main complaint with the EM was slow sparging and slow draining when using it for my boil. Advice from the collective was to (1) make sure the valve was all the way open (it was) and (2) replace the valve with something bigger. In some correspondance with Jack, I checked things out more thoroughly and did a semi-quantitative test. I removed the entire spigot, and with help from a paper-clip and Beer Line Cleaner, removed some gunk from the valve --- it's only 1/8" inside there, so it's easy to get gummed up. I don't know if the gunk was from UTS error (user too stupid), a gremlin, or a quality control glitch. I never performed an adequate test of flow before use, so the world may never know. In any case, after that, the valve drained a gallon of water in about 2.5 minutes. Well within what Jack quotes as his results. So I stand corrected in my complaints. I learned two things from Jack that were not explicitly clear from his directions -- maybe some other folks can learn from this: 1. Let things settle before opening the valve. This lets the grain (or hops if you're draining the boil) do the bulk of the filtering rather than the screen. 2. Very important (i.e., please add to the directions, Jack): attach a hose to the outflow -- the semi-rigid plastic tuning, 3/8" ID works well with a simple friction fit. This allow sufficient head to improve the flow immensely. It even acts as a sort of siphon -- when the level in the kettle is below the level of the actual spigot, liquid will still flow out as long as the inlet to the strainer is below the liquid. In any case, thanks to Jack for helping me figure this out. - --Danny Boy Return to table of contents
Date: Tue, 17 Feb 1998 10:03:31 +0000 From: "Jesse Benbow" <benbowj at ava.bcc.orst.edu> Subject: indoor propane use In HBD #2639, "Wills, Frederick J (MED)" <Frederick.Wills at amermsx.med.ge.com> writes: >I continuously read about the inherent danger in using propane >burners indoors. The gas being heavier tends to pool at floor level >and can then be ignited by an ignition source. Boom.... If this is >such a dangerous situation, why do many people have bottled LP >gas (propane) delivered in large bottles or to tanks that remain >outdoors but the gas is then run into the house to fuel furnaces, >cook stoves and ovens as well as water heaters? Wouldn't any >of these appliances be just as likely to malfunction with the same end result? My house has several appliances which run on propane (stove, furnace, water heater). Both the water heater and the furnace have pilot flames which are always lit. There is a thermocouple wire (I think that's what it's called) held in place directly in the pilot flame. A thermostat tells the main burner when to come on, but the valve to the main burner and the pilot light will only allow propane through if the thermocouple is hot enough. When lighting the pilot flame, you have to hold down a button to override the thermocouple thermostat until it is hot enough to let propane through. In other words, if there isn't a flame to burn the propane, no propane is released to leak into the rest of the house. They are also vented to the outside to prevent CO buildup in the house. Hope that explains things clearly enough, Jesse Benbow in Medford, OR Return to table of contents
Date: Tue, 17 Feb 1998 10:28:41 -0800 (PST) From: Bob McDonald <rcmcdonald at yahoo.com> Subject: floating sediment Howdy folks - I'm hoping somebody could lend me a hand with a recent batch I brewed. It's a yummy IPA that turned out great. Well, tastewise, anyway. It's been sitting in the keg for about 6 weeks now. Problem is that I screwed up during fermentation and forgot to add finings, which wouldn't have been a big deal except that I decided to add isinglass to the keg. BIG mistake. I figured the first few pints would be sediment, and the rest would be clear. Nope. Now any beer I pour has large floating pieces of crud floating in it. Not the kind of thing my friends enjoy drinking. I'd thought of filtering it through a strainer into an empty keg, but I'm worried abouit oxidation. Since it's already carbonated, I think I'd also get a foamy mess. Do any of the experts here have a good solution? Thanks much for your help. Bob McDonald Washington D.C. _________________________________________________________ DO YOU YAHOO!? Get your free at yahoo.com address at http://mail.yahoo.com Return to table of contents
Date: Tue, 17 Feb 1998 14:44:57 -0500 From: David Kerr <dkerr at semc.org> Subject: Why a duck? On 13 Feb 1998 EFOUCH at steelcase.com wrote: > Wyeast pronounce Wyeast? >From m-w.com: epenthesis \i-PEN-thuh-sus\ (noun) - the insertion or development of a sound or letter in the body of a word Dave Kerr - 10 mi SW of Fenway Park Return to table of contents
Date: Tue, 17 Feb 1998 15:02:38 -0500 From: AJ <ajdel at mindspring.com> Subject: Osmosis/Chloramine/Propane Dave Burley argues that "osmotic pressure" can't be used to explain what happens during sparge and, of course, he's right but let's take a further look at osmotic pressure. If two portions of solution have different concentrations of solute (sugar) they will also have different concentration of solvent (water). The two potions will be at different chemical potential with respect to the solvent (RT times the log of the activity of the solvent which is proportional to its concentration). Solvent will flow, if possible, from the concentrated solution to the dilute one as matter moves (or reacts) to equalize chemical potential. If the two portions are separated by a membrane permeable only to solvent then solvent can flow and will thus diluting the concentrated solution to the point where it is as dilute as the dilute solution. At this point the concentration of solvent will be the same on both sides of the membrane, the chemical potentials will be the same and flow will stop. Osmotic pressure is the amount of pressure which must be applied to the concentrated side to prevent this flow. It is proportional to the molar concentration of solute and the magnitude is surprising. Sucrose at 0.2 molar concentration yields an osmotic pressure of about 5 atmospheres! Focusing attention now on the solute: in the same solution pair the concentrations of solute are also different and the chemical potentials of the solute species are also different so that if a membrane permeable to only solute molecules separates the two, solute molecules will move to the dilute side until solute concentrations, and chemical potentials, are the same on both sides at which point the flow will stop. An osmotic pressure can be defined for this situation as well and thus the value of the osmotic pressure depends both on the presence of a membrane (Dave's point) and on what the membrane passes. If a membrane is permeable to both solvent and solute (or if there is no membrane present, as in a sparge vessel) to limit the motions of species) solvent (water) molecules will flow into high solute (sugar) concentration areas and solute molecules will flow into low concentration areas until there are no concentration and hence chemical potential gradients remaining for either species. This is the equilibrium condition which, of course, is never reached in a sparge vessel because of the flow. Thus while it is clear that there is no osmotic pressure developed because both solvent and solute can flow it is nevertheless clear that what does happen, equalization of chemical potential by migration of molecules, is very closely related to what happens in osmotic flow. I recommend, therefore, overlooking this minor error as it was clear what C.D. intended (but I do think it was proper of Dave to point it out). * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Frederick Wills commented that chloramine would probably not kill yeast. Chloramine will kill yeast, if not as effectively as free chlorine, but there are lots of other things for chloramine to oxidize in wort and the chloramine dose is designed for 10's of cells per 100 mL not the millions of cells per ml we strive for in pitching. Thus the main reasons for chloramine removal are those Frederick cited and not yeast toxicity. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * In the same post Frederick asked about the dangers of propane indoors. This one hasn't come around recently and Frederick asks the question slightly differently. I would guess that the main reason the propane cylinders come covered with caveats is to protect the supplier from liability. The stupidity of the human race knows no bounds and we're all aware that plaintiff's attorney's job is to make an innocent party with money appear to be responsible for the consequences of the acts of a negligent party with none. As a practical matter, a propane cylinder being moved from storage to the basement (or wherever) and back and being repeatedly connected and disconnected via rubber tubing to a portable burner is more likely to develop a leak than hard lines which have been permanently installed in protected runs. And yes, natural gas does behave the same way in reverse. Someone posted here a couple of years ago that the insurance adjuster knows upon arrival at the scene whether it was a natural gas (attic missing) or propane (bottom of house blown out) accident. Finally, explosion isn't the only hazard. If you are using propane indoors please buy one of those CO detectors that measures and displays carbon monoxide levels and integrates them over time. Return to table of contents
Date: Tue, 17 Feb 1998 21:29:33 +0100 From: "Hubert Hanghofer" <hhanghof at netbeer.co.at> Subject: Weissbier 4VG In HBD#2636 Samuel Mize gave a summary about maximizing clove in a weissbier > 2) Fermentation temperature. Most recommend cooler, a few warmer. My > guess is, those saying to go warmer are starting much colder. We > definitely want to get below 65F, one claims 40-50F. Warmer than this > brings out banana esters, and supresses clove. Lowering temps below 18C/64F has only little effect on 4-vinyl guaiacol (4VG) but increases the risk to get stuck fermentations. Many wheat yeasts - including the widespread Weihenstephan #68 (WYEAST #3068?) - are sensitive to cold temps *in* the fermenter and *may* go dormant below 18C/64F . As has been noted in HBD#2637 by Steve Alexander fermentation temps around 20C/68F are optimal. -Try to stay below 22C/72F but above 18C/64F until diacetyl has been reduced by the yeast. What I'm missing so far is the importance of yeast vitality! Weizen yeast that has been stressed by repeated closed fermentations looses it's ability to produce 4VG. When using fermentation tanks, commercial breweries replace the yeast after 2-3 fermentings to get the right level of 4VG (1.2-1.7 ppm) or they use continuous propagators to obtain pitching quantities. - Usually no problem for us, because we rejuvenate the yeast anyway when preparing starters. But if you harvest the yeast it's good practice to propagate it from small amounts rather than direct re-pitching. According to my experience open fermentation may produce more aromas / flavors. Try to split a batch, using parallel open and close fermentation and you may be surprised! Recently there was a seminar held by Prof. Back in Weihenstephan, that focused on brewing wheat. I'll try to get hold of the papers and see what new insights they offer. ~~~~~~~~~~~~~~~~~~~ Many thanks for the infos on roasting barley. I got help via email by Ken Schwartz and Andrzej Sadownik and in HBD#2638 by Dave Burley. The offered timing schedules differ a bit but I understand that I have to watch for the right grain color. A final temperature of 230C/450F seems to be ok. CHEERS & sehr zum Wohle Hubert in Salzburg, Austria Return to table of contents
Date: Tue, 17 Feb 1998 14:58:28 -0600 (CST) From: Al Korzonas <korz at xnet.com> Subject: Fluid dynamics John writes: >It contains information on designing and building a tun, as well as >summarizing most of the fluid dynamics discussion from a previous >article (Fluid Dynamics of Lautering) which I had co-authored in '95 >with Paul Prozinski - a civil engineer. I checked with BT and they said >that they would post that article in a week or two. It contains >discussion of flow rates (re. Narziss), and compares simple drainage >models of an Easymasher-type, tubing manifold, and a false bottom. It >addresses the relationship between flow rate and drain area/coverage >towards achieving the best extraction. It's all very similar to what I posted to HBD on October 26, 1992. John and I discussed this offline and he says he hand't seen my post before submitting his article to BT. Note, however, that back in 1992 I had never used an EasyMasher(tm) and was strictly speclulating based upon what little knowledge I had about drainage and some very foggy recollections of my fluid mechanics courses. I've since retracted my initial statements about the limitations of small-area "false bottoms" after I saw the results of the "Laeuter Tun Experiment" that Steve Hamburg and I performed, I wrote up and which was published in the Great Grains Special Issue of Zymurgy (1995, I believe). The bottom line in this experiment was that there *ISN'T* that much difference in extract yield between the various laeutering systems. I was one of the biggest critics of the EasyMasher before our experiment and now I'm one of its strongest supporters. See my website and note the laeuter tun design of my home system. What's that quote about theory and practice? Al. Al Korzonas, Palos Hills, IL korz at xnet.com My new website (still under construction, but up-and-running): http://www.brewinfo.com/brewinfo/ Return to table of contents
Date: Tue, 17 Feb 1998 15:11:25 -0800 From: George_De_Piro at berlex.com Subject: Diacetyl Hi all, Pat has problems with too much diacetyl in his pilsner. AJ correctly points out PU is one of the benchmarks of the style and has noticeable diacetyl. Despite this, most homebrew judges will site diacetyl as a flaw in a pils (as would many pro brewers), so if Pat wants to win ribbons (or if he doesn't like buttery pils) he needs to know how to get rid of it. AJ gives some good advice on getting rid of it, but I'd like to remind everyone of the importance of determining the CAUSE of diacetyl before trying all sorts of stuff to reduce it. If you look back to one of my Jan. posts you will notice the instructions for doing a "forced diacetyl test." To reiterate (I like that word): take a sample of beer, split it into two aliquots. Heat one to 60C (140F) for a short time (30 min. or so) while keeping the other cool. It is probably wise to cover the heated sample to contain the volatiles. Cool the heated sample and smell/taste both. What this will do: yeast do not make diacetyl. Yeast produce alpha-acetolactate (AAL), the precursor of diacetyl. It is not detectable by smell/taste in the concentrations found in beer. This compound will become diacetyl over time. This reaction is accelerated by heat and pH < 4.5. That is why your beer may taste clean before the diacetyl rest, but reek of butter after it: you warmed the young beer just long enough to form the diacetyl, but then cooled it before the yeast could reabsorb it! Obviously, it is important to have ample yeast in contact with the beer during the diacetyl rest, too. If your heated beer sample tastes like diacetyl, and the cool sample doesn't, then you have a substantial amount of AAL in your beer. If this is the case, you should do an extended diacetyl rest. Repeat this test until the heated sample remains neutral. At this point, the yeast have done their job and you can move on to lower temp lagering for the purpose of colloidal stability and flavor maturation. If the heated sample does not reek of butter, yet your beer develops diacetyl, then you must look elsewhere to the source of your diacetyl. Pediococcus bacteria are excellent producers of diacetyl, and could be the culprits. This is a good time to bring up the purpose of long, cold lagering. Unfortunately, I don't have time right now to start this discussion. Look for a post tomorrow... Have fun! George De Piro (Nyack, NY) Return to table of contents
Date: Tue, 17 Feb 1998 11:46:06 -0800 From: Jack Schmidling <arf at mc.net> Subject: EM Flow "Pardon my butting in... If tubing to the EM is below the spigot and flexible tubing is connected to the spigot, there'll be a trapped air pocket in the tube/spigot. I humbly suggest that is only a possibility, not a given. If you look at the angles and bends, it should be obvious that air will not get trapped. I also pointed out that the fluid flows are based on the fact that the mash tun is more or less full during the sparging process. It was not designed to be used with an inch of liquid on the bottom. js - -- Visit our WEB pages: Beer Stuff......... http://ays.net/jsp Astronomy....... http://user.mc.net/arf ASTROPHOTO OF THE WEEK..... New Every Monday Return to table of contents
Date: Wed, 18 Feb 1998 12:25:08 -0800 From: Andy Walsh <awalsh at crl.com.au> Subject: irish moss (IM) Hi. I've just received the latest JIB which has an article on fining agents, irish moss in particular. I have just reread Mort O'Sullivan's post and had some points of relevance (further discussion?). Mort suggested that the beginning of the boil may be better for IM addition as the higher pH at the beginning of the boil will aid protein (+) and kappa carrageenan (-) flocculation. Mort>At a higher pH many of the proteins in wort will have a net charge that is more positive than at a lower pH Isn't it the other way around? If the wort pH is below the isoelectric point of the protein the protein is positive. As the pH drops the charge becomes more positive. Am I missing something? (scratching head) In any event whilst it is true that less irish moss is required at higher boil pH, the exact mechanism is very complex and still not well understood. It is far more complicated than simple positive/negative flocculation and research is still ongoing on the exact mechanism. Leather says copper finings have NO effect on hot wort clarity. The main effect of copper finings is to aid in cold break formation. The only reason to add them to the boil is to dissolve the K carrageenan which is insoluble below 60C and can be thermally denatured by boiling for a long time. This is the reason most texts suggest a short boil time. Leather suggests that 30 minutes will not adversely affect copper fining peformance, however. I have read similar things elsewhere about the lack of an effect on hot break (except homebrew books - just ignore those!). The correct amount of irish moss to add is highly dependent on many factors. Most homebrew texts recommend far less than is ideal (1/2 teaspoon per batch instead of ~1 tablespoon), so in many cases it won't do much at all. Using even 30% less than the optimum can result in poor cold break flocculation. My feeling is that it is a bit of a placebo, unless you determine experimentally the correct amount to use for a particular recipe. (yes I use it - no I don't work out the dosage. It just makes me feel better!) Andy from Sydney. RV Leather "From field to firkin: an integrated approach to beer clarification and quality" JIB v104(1) 1998. pp 9-18. Return to table of contents
Date: Tue, 17 Feb 1998 18:44:47 +0000 From: irajay at ix.netcom.com Subject: Re: Mash Efficiency I would think you would put down 100% because that is what you get for extracts. It's only grain mashers who have to worry about how efficient they are getting. This, of course, assumes you are actually getting 36 points of gravity per pound extract per gallon water for your liquid extract and 45 point of gravity per pound extract per gallon water for your dry. By the way. Although I'm not absolutely certain about this, if you check out Mark Riley's "Recipator" at the Brewery website, I think that one eliminates the need to put in mash efficiency if you are doing all extracts. Whatever the case, it is such a great piece of software you need to check it out. Good luck, Ira Return to table of contents
Date: Tue, 17 Feb 1998 21:53:24 EST From: AlannnnT at aol.com Subject: Propane and Frederick Wills Frederick asks >>>> This is obviously a scary scenario, and one to be avoided... but just how real is this danger? [propane indoors] >>>>Real enough. When propane leaks it concentrates at the lowest point. [It is still very explosive in it's leaked state] Propane is so powerful an explosive, that the gas in one BBQ bottle can lift your house off the foundation and ruin your neighbors' houses and cars on the street. Ask any fireman. Training for propane leaks is more intensive than any other hazard. NO MISTAKES can be made evacuating the gas. Water is used to push the gas out,sometimes requiring the basement of the offending home to be filled with water! If this is such a dangerous situation, why do many people have bottled LP gas (propane) delivered in large bottles or to tanks that remain outdoors The greatest leak hazard is at the valve, outside. Would running a hard gas line from a bottle outside to a homebrew burner used indoor be less risky? Yes, but get a pro plumber to plan, inspect, install etc. Also, why wouldn't Natural Gas which is lighter than air tend to pool-up at ceiling level and present the same hazard in reverse? Natural Gas mixes well with air. Hence, it is less explosive as it leaks. Its smell [which is injected into it by the gas co.] makes a good marker, so you know it's there. And being light it can be evacuated by a fan. Especially in winter months when houses are closed up tight and these heating appliances are typically in use? My quess only, but more people probably die from carbon monoxide.It has no smell and you fall asleep before you know you are being poisoned. Happy Trails, Alan Talman Return to table of contents
[Prev HBD] [Index] [Next HBD] [Back]
HTML-ized on 02/18/98, by HBD2HTML version 1.2 by K.F.L.
webmaster at hbd.org, KFL, 10/9/96