HOMEBREW Digest #703 Fri 16 August 1991

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	FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
		Rob Gardner, Digest Coordinator


Contents:
  Sulfites ("Spencer W. Thomas")
  centennial hops (Russ Gelinas)
  Re: Homebrew Digest #702 (August 15, 1991) (David Resch)
  Re: Homebrew Digest #702 (August 15, 1991) (David Resch)
  beer frige & infection? (Dave Barrett)
  Re: Centennail Hops (Don McDaniel)
  prevent infections/lager&ale malts/centennial hops (Tony Babinec)
  RE: Brewing salts (CaCl) (Bill Dyer)
  Pumpkin Ale (Dances with Workstations)
  need some east coast homebrew shops (dave ballard)
  re: Some questions (lg562)
  HUNTER AIR-STAT  (card)
  Re: making mead (adietz)
  On Chillers (Martin A. Lodahl)
  Pale Malts (Martin A. Lodahl)
  Ka-BOOM (Martin A. Lodahl)
  Wanted: recipe for "lager style" ales (GC Woods)
  CaCl (STROUD)
  Calculating Alcohol Percentage (Alan Edwards)
  The Malt Extract Report (LONG!) (Martin A. Lodahl)
  astringent beer, partial mash? and Guinness (Rich Lenihan)

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---------------------------------------------------------------------- Date: Thu, 15 Aug 91 08:32:15 CDT From: andy at wups.wustl.edu (Andy Leith) Does anybody know of somewhere I can get hold of the cultures necessary to make a kriek, for less than the $45 that it costs from UC Davis? Thanks Andy Leith andy at wups.wustl.edu IP 128.252.144.4 Return to table of contents
Date: Thu, 15 Aug 91 09:45:45 EDT From: "Spencer W. Thomas" <Spencer.W.Thomas at med.umich.edu> Subject: Sulfites Unfortunately for those sensitive to sulfites, a certain amount can be produced during fermentation. This is why almost all (in fact all that I've seen) wines are labelled "contains sulfites". I don't know if this is also true of beer (I haven't seen such labels on beers), maybe it's something in grapes that does it. There's a fellow in Michigan that makes "organic wine". Some years, he can leave off the sulfites warning, others, he has to put it on (I assume he's testing the wine after it's done). =Spencer W. Thomas HSITN, U of Michigan, Ann Arbor, MI 48109 spencer at med.umich.edu 313-747-2778 Return to table of contents
Date: Thu, 15 Aug 1991 9:46:53 EDT From: R_GELINAS at UNHH.UNH.EDU (Russ Gelinas) Subject: centennial hops Centennial hops used to be known as CFJ90. I've used them under both names, the harvests of 1989 and 1990. The 1989 version was better, but I understand that the 1989 harvest was much better in general than the 1990 one. Anyway, Centennial are a high alpha hop, and I believe they are a somewhat new strain. Russ Return to table of contents
Date: Thu, 15 Aug 91 08:29:48 MDT From: resch at craycos.com (David Resch) Subject: Re: Homebrew Digest #702 (August 15, 1991) > > How can I be sure that the bottle I am about to open is not a bomb? > Any hints would make opening the first bottle of a batch much less > traumatic for me, from now on. > > Mitch Well, you can never be sure, but a very good indication of a "bomb" is when the cap takes on a convex shape due to the excess pressure in the bottle. Dave > Subject: Centennial Hops > > Has anyone had any experience with Centennial hops? I picked some up > the other day because I had never tried them. When I got home and > checked my references on hops (including the Zymurgy Hop issue), I > couldn't find anything on Centennial. I assume that it is a fairly > new variety? So what's it like? Thanks. > > - -- Mike While I don't have any experience using them, I believe that Centennial is a relatively new "super-Cascade" variety, i.e., it has a lot of the Cascade characteristics for hop flavor and aroma, but is substantially higher in alpha acid content. I believe that during development it was referred to as "CFJ-90" which may be how it is listed in the special hop issue of Zymurgy. I'm not sure of the alpha acid content (don't have any info with me here at work), but if memory serves me (it often doesn't) they would be in the 10-12 percent alpha acid range, so discression is advised if they are to be used for bittering. Dave Return to table of contents
Date: Thu, 15 Aug 91 08:29:48 MDT From: resch at craycos.com (David Resch) Subject: Re: Homebrew Digest #702 (August 15, 1991) > > How can I be sure that the bottle I am about to open is not a bomb? > Any hints would make opening the first bottle of a batch much less > traumatic for me, from now on. > > Mitch Well, you can never be sure, but a very good indication of a "bomb" is when the cap takes on a convex shape due to the excess pressure in the bottle. Dave > Subject: Centennial Hops > > Has anyone had any experience with Centennial hops? I picked some up > the other day because I had never tried them. When I got home and > checked my references on hops (including the Zymurgy Hop issue), I > couldn't find anything on Centennial. I assume that it is a fairly > new variety? So what's it like? Thanks. > > - -- Mike While I don't have any experience using them, I believe that Centennial is a relatively new "super-Cascade" variety, i.e., it has a lot of the Cascade characteristics for hop flavor and aroma, but is substantially higher in alpha acid content. I believe that during development it was referred to as "CFJ-90" which may be how it is listed in the special hop issue of Zymurgy. I'm not sure of the alpha acid content (don't have any info with me here at work), but if memory serves me (it often doesn't) they would be in the 10-12 percent alpha acid range, so discression is advised if they are to be used for bittering. Dave Return to table of contents
Date: 15 Aug 91 10:09:16 EST From: Dave Barrett <DAVE.BARRETT at OFFICE.WANG.COM> Subject: beer frige & infection? I have a friend that is trying to get a tap system together for his home. He wants to have 1/2 barrels of Catamount port on tap. The problem is to find an appropriate refrigerator. All the 5 cubic foot one's he has been able to find appear to be made by Japan Inc. and come in one of two versions: one has the cooling coils built into the shelves and the other has a built in freezer. Since he would perfer not to get a full size frige, does anyone know of a source of domestic 5 cu ft friges? Something in the Massachusetts/New Hampshire area would be nice. Direct replies are fine. On another note. Last May I made a honey ginger beer that was a take off on Rocky Raccoon Larger. The wort that went into the primary was an opaque mustard/honey color and tasted pretty good. After about 4 days I transferred it to the secondary. Everything looked fine, but still opaque. Four weeks later the beer had cleared a bit and there was a great deal of trub. I could also see a 'hazy' layer in the middle of the carboy. Since it smelt and tasted ok I bottled it anyways. After 4 weeks in the bottle (the beer, not me) I I began to suspect that something was wronge. The haze was still there. So I brought a bottle into work to show to another brewer to get his opinion on what was happening. Naturally transporting the bottle shook all the dregs back up into the beer. We left the bottle on my desk for the weekend to give the dregs a chance to settle out. A surprise was waiting for me when I came to work on Monday. (Nope this isn't another glass hand grenade sob story). The bottle has cleared. Totally. Not only had the dregs settled back out, but the haze was gone as well. This caused me to do something completely unnatural. I ran home and violently shook 5 gallons of homebrew. Every bottle cleared after 2 to 3 days. The beer still smells great and tastes pretty good but a little too sweet for my taste. The $64,000 question is what was that haze? Where did it come from and how do I keep it from coming back? This batch was the first time I ever brewed with honey. Does that have something to do with it or did the dog sneak some dirty diapers into the carboy? Thanks in advance, db Return to table of contents
Date: Thu, 15 Aug 91 09:19:31 -0600 From: dinsdale at chtm.eece.unm.edu (Don McDaniel) Subject: Re: Centennail Hops Regarding the use of Centennial hops: I got four ounces from Freshhops this spring as they were out of all high-alpha varieties that I was familiar with. I have since used some in a couple of batches of ale (I believe a brown ale kit and an all grain pale, although my brewsheets are not here at work). They have given perfectly satisfactory results when used for bittering (60 min. boil). I am in the habit of using Cascade or Willamette for aroma and a high-alpha variety for bittering. Used in this way, I don't think the variety of bittering hop is really important, assuming of course you account for the alpha acid content in determining the appropriate quantities. The theory behind this disregard for variety is that in a 60 min boil, the aromatics which distinguish hop varieties are boiled away. Consequently, you might as well save some money and use the highest alpha variety you can find. Don McDaniel Return to table of contents
Date: Thu, 15 Aug 91 10:18:57 CDT From: tony at spss.com (Tony Babinec) Subject: prevent infections/lager&ale malts/centennial hops Here are some comments on recent discussions in HBD. Regarding preventing infections: there were many good suggestions in recent installments of the digest, but I thought I'd mention or reinforce a few. - After acquiring carboys for fermentation, I've used my original plastic fermenter as a sterilizer bucket. EVERYTHING that will touch the boiled wort gets an immersion in the plastic fermenter. That includes spoons, funnels, siphon tubes. Immediately after siphoning wort, I siphon some of the chlorine water into the tube and immerse it. Glass carboys should be visually inspected, scrubbed with a brush, and also treated with a mild chlorine solution. Occasional use of a caustic such as lye (Drano, Red Devil) will clean and sterilize, but be careful with it! Lye treatment followed by scouring pads will usually remove stubborn burnt malt from your brewpot. On the other hand, I haven't used it on siphoning tubes, of course! - Boil all water prior to use. - Get a quick cold break. When I began by making extract beers, I'd add water at the end to bring the volume up to 5 gallons. When I moved to partial mash/all mash brews, and had a greater volume of wort, I bought a wort chiller. Slowly-cooling wort goes through temperature danger zones where bacteria might take hold. A rapid cooling is good insurance against them taking hold. - Build up the yeast prior to pitching. If you have no special equipment, boil some dry malt extract to make a wort starter, pour it into a sanitized 16 oz beer bottle, and cover either with sterile cotton gauze or even a bit of aluminum foil. Or, a local science supply store had some 1000 ml flasks, and these were easily fitted with stoppers and fermentation locks. There are few things worse than a long lag period between the time the yeast is pitched and visible signs of fermentation appear. As pointed out many times, a quick start of your yeast is reasonable insurance that the yeast will dominate the fermenter environment and suppress bacteria. As pointed out in the Yeast issue of Zymurgy, commercial packaged yeasts, especially the otherwise wonderful WyYeasts, are of insufficient volume for a 5-gallon wort. The point about these and other suggestions is that it's unlikely that the average homebrewer can work in a truly sterile environment, however, some of these practices at least stack the odds in your favor. Regarding lager/ale malts: There are several things going on. I'm neither a physicist or chemist, and I don't have my references handy (they're at home, I'm at work), but here's what I recall. Our local supply store has the following pale malts: 6-row American, 2-row American, 2-row German, and British (2-row) pale ale malt. Of these malts, only the pale ale malt should be used for making pale ales. Malts vary in the degree to which they are modified and the degree to which they are kilned. Modification refers to how much the acrospire (embryonic barley plant) is allowed to germinate. Kilning refers to length and temperature of drying of the sprouted barley. British pale ale malt is a well-modified malt that is kilned a bit more than the pale lager malts. Because it is well-modified, you can use a single infusion mash, although I always do step infusion. The degree of kilning of British pale ale malt accounts for the wonderful color of pale ales. Another effect of kilning is to destroy enzymes. This is why highly-kilned malts (chocolate, black) are used as specialty malt add-ons to a pale malt or extract base. This is also why if you want to use flaked maize, wheat malt, or other specialty grains in small amounts in a pale ale, you might consider adding a bit of 6-row American for its enzyme content. 6-row American has high-enzyme, high-protein content. Because of high-protein content, it needs a protein rest. Because of high-enzyme content, it is particulary suited to American-style adjunct brewing, where corn and rice become routine ingredients in the recipe. Discussions of American 6-row always caution that since it is somewhat husky, too-hot sparge water can contribute to husky, tannic flavors in the wort. German 2-row malt is suited for pilsners. It tends to be less-modified. If it were especially undermodified, you might have to use a decoction mash. If it isn't too undermodified, you could use a step-infusion mash. I've had success with step-infusion. See Noonan's books and articles for all the reasons why you'd want to do a decoction mash. See Miller's "Contintal Pilsner" for more on this topic. American 2-row tends to be fully-modified and not so high in protein or enzyme content as American 6-row. In sum: use only pale ale malt when making British pale ales; use other pale malts when making lagers or Continental ales. If you use pale ale malt to make a lager, you'd have a difficult time making a truly pale beer. If you use other malts to make a pale ale, you'd have difficulty getting the right color. Plus, these other malts give rise to DMS flavors which at appropriate levels are okay for lagers but wrong for pale ales. Of course, the above are disclaimers, and it would help to have more information on any particular malt from the supplier! Centennial hops: Aren't these the same as CFJ-90? I think I used some CJF-90s with an alpha of 7 or so. They're suitable for brewing West-Coast-style ales. I'm not certain, but aren't they descended from Cascades? Return to table of contents
Date: Thu, 15 Aug 91 10:46:55 CDT From: dyer at marble.rtsg.mot.com (Bill Dyer) Subject: RE: Brewing salts (CaCl) [Stuff about carbonate and bicarbonate removed] > > Please correct me if I am wrong about the above chemistry (but don't > correct my typo's please!). Miller talks about similar reactions using > Calcium sulfate, but I don't want to add all that sulfate to my water > which already has too much to being with (begin with). A couple things here seem questionable, first, I'm not sure that boiling will convert bicarbonate to carbonate, in fact I'm not even sure what carbonate and bicarbonate are, I'll look this one up tonight. Second, you are assuming and calcium carbonate will precipitate, is this a good assumption? I don't know. Thirdly, and this one I am pretty sure about, cloride ions will not simply become 'volatile' and evaporate. I don't think you would want that anyway since chlorine gas is not pleasant. The reason is that chloride ions have an extra electron given to them by the calcium atom when the ionic bond was formed. In order to convert chloride ions into chlorine, they have to give up their electron to some other positive ion, which in turn will become a non charged molecule. This is not likely to happen on your water since there is nothing to accept the electron (positive metal ions will not do this since they gave up their electrons in the first place, besides you do not want calcium or sodium metal floating around in your brew). You may be able to get the chlorine out of the water by applying a current to the water, for instance this is how electro-plating works. A metal is deposited on the surface of some other metal and a gas is released. _____________________________________________________________________________ | I wish I could sit on soft pillows, |Bill Dyer (708) 632-7081 | | and eat molten lava. | dyer at motcid.rtsg.mot.com | | -King Missle | or uunet!motcid!dyer | Return to table of contents
Date: Thu, 15 Aug 91 12:11:52 EDT From: Dances with Workstations <buchman at marva1.ENET.DEC.COM> Subject: Pumpkin Ale Greetings, The season for making pumpkin pie approaches, and what better time to brew a Pumpkin Ale? I hear there is a recipe for "Punkin Ale" in this summer's Zymurgy, but my supply store is out of that issue. Could someone mail me, or post, a copy of that recipe? Or does anyone have a favorite extract-based recipe for pumpkin beer? Thanks, Jim Buchman buchman at marva2.enet.dec.com Return to table of contents
Date: 15 Aug 1991 12:52 EDT From: pyuxe!dab at bellcore.bellcore.com (dave ballard) Subject: need some east coast homebrew shops Hey now- I'm new to this digest and to homebrewing in general and I could use a lttle help from you guys. I'm starting to look for starter kits etc, and I got a catalog from Great Fermentations of Santa Rosa (CA). The stuff in the catalog is great, but the problem is that ordering from the left coast will cost me a small fortune in shipping. Can anyone recommend a supply house in the central NJ area? I think there's a place on Staten Island, but I'm not sure. Any info would be appreciated... -dab ================================================= dave ballard dab at pyuxe.cc.bellcore.com Return to table of contents
Date: Thu, 15 Aug 91 09:56:30 PDT From: lg562 at koshland.pnl.gov Subject: re: Some questions Date: Wed, 14 Aug 91 12:39:23 MET DST >From: etxsral at hal.ericsson.se (Lars Nilsson) Here is some questions: 1. What is Corn Sugar ? (Sorry for this stupid question but I have never seen this type of sugar in Sweden or the U.K. ) This is glucose, aka dextrose, aka D-glucopyranose. Sorry I can't answer the other question. Michael Bass Molecular Science Research Center, K2-18 Battelle - Pacific Northwest Laboratory Richland, Washington 99352 lg562 at pnl.gov Return to table of contents
Date: Thu, 15 Aug 91 13:58:54 EDT From: card at apollo.hp.com Subject: HUNTER AIR-STAT Boston Area: The Hunter Air-stat can be bought at Lechmere's for $24.95. I know for certain that the Cambridge and Nashua NH stores both have them. Thanks to those that responded. /Mal Card Return to table of contents
Date: 15 Aug 1991 14:38 EDT From: afd at hera.cc.bellcore.com (adietz) Subject: Re: making mead >Date: Tue, 13 Aug 1991 17:23:00 -0400 >From: MIKE LIGAS <LIGAS at SSCvax.CIS.McMaster.CA> >Subject: Making Mead > > >PS- mead IS an aphrodisiac!!! > Yup, this is true. ;-) -A Dietz Bellcore, Morristown Return to table of contents
Date: Thu, 15 Aug 91 12:50:28 PDT From: Martin A. Lodahl <pbmoss!malodah at PacBell.COM> Subject: On Chillers In HOMEBREW Digest #701, Steve Anthony asked: >I had thought that getting a lenth of copper pipe and having a friendly >local plumber coil it for me would be a start. I could then sweat solder >(using non-lead solder, of course) some elbows and straight runs of pipe on >to the coil; perhaps using some flexible hosing and hose clamps for areas >where one might need to be able to bend the tube. I thought I might even >put a valve and perhaps a thermometer on the output side. > >I had then thought that putting the coil of the chiller in my kitchen sink >and surrounding it with crushed ice water would cool the boiling wort >appropriately. But will it? ... > >Any comments, answers, etc are welcome! Sounds like the Ultimate Chiller. But you can achieve the same effect much more simply with an immersion chiller. I made mine by taking a 50' coil of 3/8" soft copper tubing (readily available at hardware stores, plumbing supply stores, etc.), added a compression fitting to each end, along with a 3/8"-male-pipe-to-1/4"-female-pipe bushing and 1/4" hose barb. To each hose barb I attached flexible plastic tubing. I used food grade because that's what I had; as the wort won't touch it, lesser grades are fine. To one of those hoses I attached a "Gilmore" (1/4" hose barb to 3/4" female garden hose) fitting. I re-coiled the copper tubing (easily done) to fit inside my boiler. I fill the thing with hot water, and place it in the boiling wort to sterilize for at least 20 minutes. After turning off the heat, I attach the Gilmore fitting to a water tap, and slowly run cold water through it, capturing the VERY hot water coming out of the exhaust hose for use in cleanup. In a half-hour, this will get it down into the 80's(F). I usually don't let it go that long, shifting over instead to icewater recirculation after the wort temperature drops below 100F. Simple, works great. After I'm done with it, part of the cleanup of it is always to blow as much water as I can out of the coils. I used to be more relaxed about this, but a hard freeze last winter destroyed my previous chiller ... = Martin A. Lodahl Pacific*Bell Systems Analyst = = malodah at pbmoss.Pacbell.COM Sacramento, CA 916.972.4821 = = If it's good for ancient Druids, runnin' nekkid through the wuids, = = Drinkin' strange fermented fluids, it's good enough for me! 8-) = Return to table of contents
Date: Thu, 15 Aug 91 13:02:33 PDT From: Martin A. Lodahl <pbmoss!malodah at PacBell.COM> Subject: Pale Malts In HOMEBREW Digest #701, Russ Gelinas asked: > I'm confused (what's new?). What's the difference between lager malt and >ale malt? I always thought lager was 6-row, and ale was 2-row, and you >could really use either for either. But I've seen references to pale ale >malt. Is that just 2-row lager? My understanding of the differences is that lager malt is usually 6-row in North America and 2-row everywhere else, the exception being the 2-row Klages barley malted to the moderate degree of modification lager malts usually use, and frequently sold as "pale malted barley". This is versatile stuff, very akin to Continental lager malts but with nearly the diastatic power of 6-row. Pale ale malt is a 2-row malt with a very complete degree of modification, slightly more highly kilned than most pale malts. It has relatively little diastatic power, but will produce good yeild when mashed in the British single-temperature infusion menthod. = Martin A. Lodahl Pacific*Bell Systems Analyst = = malodah at pbmoss.Pacbell.COM Sacramento, CA 916.972.4821 = = If it's good for ancient Druids, runnin' nekkid through the wuids, = = Drinkin' strange fermented fluids, it's good enough for me! 8-) = Return to table of contents
Date: Thu, 15 Aug 91 13:14:08 PDT From: Martin A. Lodahl <pbmoss!malodah at PacBell.COM> Subject: Ka-BOOM In HOMEBREW Digest #702, Mitchell M. Evans described the most traumatic experience a brewer can have: > After about 6 days (which I thought was a short fermentation at the > time), the fermentation stopped. S.G. looked pretty good...not as > good as hoped, but still acceptable. Wrong Answer! I was making > some mighty fine glass grenades. The time came to open the first > one of the batch... > > Glass and beer shot 20 feet across my house, peppering the walls in > my living room, dining room, and kitchen. On the way to the walls, > the glass opened my thumb to the bone. Yee-hah. The mess was hor- > rible, as you might imagine. I bled like a stuck pig. No fun. It's interesting, though, that the "S. G. looked pretty good". You may not have done anything wrong! This may be a form of contamination noted in these pages before, where after a pause of several days fermentation resumes, sometimes continuing all the way down to 1.000! Obviously not a normal and healthy fermentation. Wild yeast seem the most likely cause. > How can I be sure that the bottle I am about to open is not a bomb? > Any hints would make opening the first bottle of a batch much less > traumatic for me, from now on. Mike Sharp has reported running across very high-pressure bottles, and has taken to lifting just a tiny bit of the cap to get a sense for how rapidly the gas "wants" to come out of solution. If it seems too vigorous, he can clamp the cap down again before it really gets going. I usually take a slightly different approach with a new batch, opening a bottle every few days after bottling. The first few aren't likely to taste that good, but if there's a developing overcarbonation problem I'd know about it before it reached the danger point. Good luck! = Martin A. Lodahl Pacific*Bell Systems Analyst = = malodah at pbmoss.Pacbell.COM Sacramento, CA 916.972.4821 = = If it's good for ancient Druids, runnin' nekkid through the wuids, = = Drinkin' strange fermented fluids, it's good enough for me! 8-) = Return to table of contents
Date: 15 Aug 91 16:41:49 EDT (Thu) From: GC Woods <gcw at garage.att.com> Subject: Wanted: recipe for "lager style" ales Does anyone have an extract recipe for making a "lager style" beer with ale yeast. I've been in brewpubs which do not have the facilities/capacity to brew lagers, but will make a similar brew using ale yeast. Thanks, Geoff Woods On another note: >From: Chris Shenton <chris at asylum.gsfc.nasa.gov> >Carboys are easier to keep clean than buckets -- they don't scratch like >plastic -- so there will be less chance of infection. I wouldn't worry You must be kidding. Maybe I am not using the correct type of brush or something, but I can wash out a food grade plastic bucket with no problem (and no scratches yet), but have a very difficult time getting all of the stuck junk off the inside of a glass carboy. If there is some gadget I'm missing to clean carboys, please e-mail me! Return to table of contents
Date: Thu, 15 Aug 1991 15:17 EST From: STROUD%GAIA at sdi.polaroid.com Subject: CaCl Chris Swingley writes, suggesting adding CaCl2 to a high carbonate water supply to precipitate the carbonate, then boiling to remove the chlorine. Bad news, Chris. You can boil until doomsday and you'd *never* get rid of the chloride. All you'd do is boil off the water. Chlorine and chloride are two different chemical species. Chlorine is a volitile gas. Chloride (an anion) ain't and it will just stay there when you boil. Chloride WILL NOT become chlorine just by heating it up in boiling water. What you are suggesting won't work. It is like saying that you can get salt (sodium chloride) out of water by boiling it. We all know that that isn't true. All you get is a more concentrated salt solution. If you try what you have suggested, you'll end up with some mighty salty tasting brew. Steve Return to table of contents
Date: Thu, 15 Aug 91 14:19:47 PDT From: rush at xanadu.llnl.gov (Alan Edwards) Subject: Calculating Alcohol Percentage Hello everyone. I would like to know the REAL formula for calculating alcohol content from starting and ending specific gravity readings. Somewhere I picked up this formula: Alcohol_by_weight = (Final_Gravity - Starting_Gravity) * 105 and Alcohol_by_volume = Alcohol_by_weight * 1.25 I KNOW that at least the second part cannot be correct, because Alcohol_by_volume and Alcohol_by_weight do not have this linear relationship--otherwise 100% alcohol by weight implies 125% alcohol by volume (powerful stuff)! That makes me suspect the first equation also. Somehow, I don't think that either equation could be linear. These must be approximations. (They were probably inferred from those potential alcohol marks on a hygrometer.) Does anyone know the definitive, correct set of equations--or at least something more accurate? Miller's book does not mention this calculation (at least I couldn't find it). If you don't know the correct equations, what do you use in practice? Thanks, -Al .------------------------------------. | Alan Edwards: rush at xanadu.llnl.gov | Member: The Hoppy Cappers | or: alan-edwards at llnl.gov | homebrew club, Modesto, CA `------------------------------------' Return to table of contents
Date: Thu, 15 Aug 91 14:43:47 PDT From: Martin A. Lodahl <pbmoss!malodah at PacBell.COM> Subject: The Malt Extract Report (LONG!) After my previous posting on the abstract(s) in Zymurgy of a report on adulteration of malt extracts, Russ Wigglesworth of the San Andreas Malts provided me with a copy of the original report. Entitled "Malt Extract: Relationship of Chemical Composition to Fermentability", by J. Paik, N. H. Low, and W. M. Ingledew of the Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, Canada S7N 0W0, it was received May 15 1990 by the American Society of Brewing Chemists, and accepted September 5 1990. It's my understanding that it was published in the February 1991 issue of their Journal. This is a very long posting, but I think the subject warrants it. The report makes fascinating reading, and clears up some points raised by the Zymurgy articles. It begins with an abstract: Forty-four commercial malt extracts used in microbreweries, brewpubs, and/or homebrewing were adjusted to 12 degrees Plato and fermented at 14 degrees C. Results were compared with those of an all-malt wort from a large Canadian brewery fermented under the same conditions. In general, the worts made from malt extracts contained lower utilizable free amino nitrogen (FAN) values, showed slower fermentation rates, and had darker colors than the brewery wort. The extracts with higher FAN fermented better than those with low FAN levels. The slow fermentation rates of some malt extracts that contained low initial levels of utilizable FAN could be improved by supplementation with assimilable nitrogen from yeast extract or the nitrogen (but not the carbon skeleton) from glutamic acid. The carbohydrate profiles of the malt extracts as determined by high-performance liquid chromatography showed considerable variation. It was possible to detect in the malt extracts the addition of, or adulteration by, lower cost adjuncts such as glucose syrup, invert syrup, liquid sugar, or high-fructose corn syrup. Significantly, one of the search keywords is "Stuck fermentation". The early part of the report describes the methods used with a level of detail one would expect of a paper of this nature. What would interest us is that "Forty-one malt extracts (all of light lager type) were purchased from a local brewing supply store. These malt extracts were called beer kits, home brew kits, concentrated brewing worts, or malt extracts for home brewing ... In addition, one bulk malt extract sample from a malting company and two bulk malt extract samples from a local brewpub were obtained". Red Star Lager yeast was used for all the fermentation studies. The first sign of real trouble apparently came when they noticed that the time the extract brews required to drop from 12P to 6P varied from a low of 45 hours to a high of 173, compared to the baseline of 51 hours for the Molsen wort. In fact, "93% of the malt extracts had demonstrably slower fermentation rates than the standard wort", with a "correlation between initial FAN level and fermentation time (to 6P) yielded an r value of 0.75 -- a correlation significant at the 0.01 probability level" for all you statisticians out there. To summarize the conclusions of the fermentation part of the study, yeast nutrients appear to be much more helpful than we've previously been led to believe, in dealing with extract worts. That fact is rather surprising: I, for one, wouldn't have expected there to be that much difference between the performance of an all-malt extract wort and an all-malt, all-grain wort. The sugar profiles provided the real bombshell. They divided the extracts into 3 groups, according to the contents listed on the labels. Groups 2 and 3 both had various supplements listed, and the analyses tracked pretty well with the labeling. Group 1 extracts, however, "were labeled at the source as pure malt extracts". Of the 21 extracts in that group, a commendable 14 had carbohydrate profiles "similar to the standard all-malt wort", which placed them in class 1. From here I quote: "Group 1 class 2 extracts had a D-glucose concentration 2.7 times that of the standard, with concomitantly less maltose and maltotriose. The two possible explanations for this sugar profile are that wort production was carried out using a longer saccharification period during the mashing process (considered unlikely as the final ethanol concentration of the beer would then be >5%), or that a glucose syrup was added to the malt extract. A single Group 1 class 3 extract was found to have 88% of its total sugar content as D-glucose. Because this sample did not contain any D-fructose, sucrose, maltose, or maltotriose, this product was highly adulterated with a high-glucose syrup". WOW! A malt extract, without a trace of malt extract! They continue: "Carbohydrate analyses of all Group 1 extracts indicated that seven of the 21 samples labeled as pure malt extracts were adulterated with glucose syrup." So there you have it. We all know that it's quite possible to make very good beer using malt extracts, but most of us have at some time had some problem extract batches. The degree of variation this study identifies suggests we may not always have been at fault. The study suggests to me a few considerations: + If you're not at least partial mashing, add yeast nutrient. It can't hurt, and might help. + Don't add sugar to an extract wort. It may already have all it can stand. + All extracts are not alike. if you're using a good one, stick with it. Happy brewing ... = Martin A. Lodahl Pacific*Bell Systems Analyst = = malodah at pbmoss.Pacbell.COM Sacramento, CA 916.972.4821 = = If it's good for ancient Druids, runnin' nekkid through the wuids, = = Drinkin' strange fermented fluids, it's good enough for me! 8-) = Return to table of contents
Date: Thu, 15 Aug 91 18:20:21 EDT From: rich at progress.COM (Rich Lenihan) Subject: astringent beer, partial mash? and Guinness Thanks to all who responded to my recent question re: ppm vs. mg/l. I feel a little guilty because I haven't done anything with the information I've received. I don't treat my water yet (but I am pre- boiling all my water now). Now some new questions: A few weeks ago I made a batch of red ale using 6 lbs. light DME, 11 g. Edme dried yeast, 3.5 oz. Goldings leaf hops, 1 cup crystal and pre-boiled water for 5 gallon volume. Two problems: 1. The brew fermented fine for about 3-4 days, then stopped. Initial SG at 1.044, subsequent readings stuck at about 1.032. I attributed this to a heat wave that killed my yeast (this is the first time I've brewed in the summer). I took another 11 g. packet of Edme dried yeast, started it in sterile wort and re-pitched into the carboy. From the taste, smell and look of the starter, the second packet of yeast seemed healthy enough (both packets purchased together). A month later fermentation is steady but sloooow. SG last Saturday was at 1.021. Is this typical of Edme or is it just the heat? The AC in my apt. stays set at about 75 F. 2. When I tasted my SG samples, there was a definite astringency caused by (I guess) boiling the crystal for too long. Can this be fixed? What I'd like to know is if there is a way to sweeeten or mellow the beer at this point without adding any more fermentables (I'd like to bottle it this year) and without raising its gravity. Also, while I'm still extract brewing, I've been giving some thought lately to mashing my own. Now most "experts" recommend starting with a partial mash to get the hang of it for a while. Why? What are the advantages to this? It seems to me that if I'm going to go through the trouble of milling, decocting/infusing, spargeing and all of the rest of it, why not mill a little more malt and do a full mash? Finally, I've read with interest the discussion re. Guinness on draft. Good Guinness is a wonderful drink (I've never been to Ireland, but I assume when saints die, they ascend to heaven on the foamy head of Guinness stout). However, noone so far has mentioned the #1 problem with getting Guinness draft in the States. Temperature. In most bars, all the kegs are kept in one room at one temperature - *cold*. So even if the Guinness is fresh and they use official Guinness tap systems, if they serve you a pint of Guinness at Budweiser temperature, it won't taste velvety smooth with complex undertones. It will taste harsh and bitter. The best you can do is to hold the glass in your hands until it warms up...if you can stand it :-) Rich Rich Lenihan UUCP: mit-eddie!progress!rich Progress Software Corp. Internet: rich at progress.com 5 Oak Park Real life: 20-I Brandywine Drive Bedford, MA 01730 Shrewsbury, MA 01545 USA (508) 754-7502 Return to table of contents
End of HOMEBREW Digest #703, 08/16/91 ************************************* -------
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