HOMEBREW Digest #2708 Fri 08 May 1998

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		Digest Janitor: janitor@hbd.org
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  pH Experiment - Background ("A. J. deLange")
  pH Experiment - Procedure ("A. J. deLange")
  pH Experiment - Data Sheet ("A. J. deLange")
  Oatmeal Stout / Wisconsin Homebrew Clubs (Matthew Arnold)
  Hop Farming (Kevin TenBrink)
  Stout head retention (John Coulter)
  Is my malt ruined? ("George De Piro")
  DO and mixing (Hugh Hoover)
  FWH extract recipes (Kevin TenBrink)
  Stainless Conical Fermenter ("S. Wesley")
  Acetaldhyde ("David R. Burley")
  SABCO mash kettle info wanted (Bill Holman)
  Dryhopping (Jeff Renner)
  South African Homebrewers ("Dallas Dahms")
  Evaporation Rates ("Henckler, Andrew")
  Boiling and evaporation rates (George_De_Piro)
  Boil rates and evaporation (michael rose)
  Covering the boil (Charles Hudak)
  Beer Evaluation (George_De_Piro)
  Trip from NYC to GABF in Baltimore (BR Rolya)
  Boil evaporation (Troy Hager)
  10% rule (Jeremy Bergsman)
  Re: Re-started fermentation in the secondary (brian_dixon)

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---------------------------------------------------------------------- Date: Wed, 06 May 1998 16:50:35 -0500 From: "A. J. deLange" <ajdel at mindspring.com> Subject: pH Experiment - Background Background: About a week or so ago I posted concerning quantifying the extent to which mash pH changes with temperature. Many books and articles say that brewers who cool their wort should subtract 0.3 units from a room temperature pH measurement to compensate for the fact that the measurement is being made cold. This number seems to derive from a table in DeClerk (who in turn got it from Hopkins and Krause, "Biochemistry Applied to Malting and Brewing", London, 1950). The table shows measured pH vs. the temperature of measurement for two mashes: one made with distilled water and one with "medium hard water". While the pH values differ for the two mashes both sets of data show a trend of very close to .004 pH per degree F. I mentioned that I usually see a rise of only 0.1 pH unit but consultation of my notes shows that it is more like .13 - .15 or about half what DeClerk's data show. I wondered whether this is yet another example of widely accepted misinformation circulating and recirculating throughout our community. This caught the eye of Lewis Bonham who is, as you know, doing a column in BT whose focus is experimentation in brewing. This is just the kind of data he'd like to have and I'd love to provide it. There is, of course, a catch. I may have a much better pH meter than Jan DeClerk ever saw in his lifetime of brewing research but I don't have the lifetime to devote to brewing reasearch (alas). Therefore, I can only accumulate a limited amount of data in reasonable time and that's why I'm asking for input from other brewers. If some of you will will pitch in we ought to be able to accumulate a fairly broad base of data. I think this is a neat opportunity for the collective (as we so often call outselves) to do something collectively. There is, of course, a catch here too and that is that differences in equipment and difference in technique may distort the data. I can't do "quality control" if I'm not there but what I can try to do is lay out a procedure which we'll hope will give consistent results when used by anyone with appropriate equipment. This procedure is little different from what is regarded as good practice but what we'll do is define a particular set of steps and ask that contributors adhere to them even though their equally good practices may differ somewhat. I will also ask that participants furnish raw millivolt readings in addition to pH readings. In this way I can see what shape your electrode is in and the raw data lets me do "calibration" and temperature compensation myself so that all data will be based on the same algorithm. I put "calibration" in quotes because it's a bit of a misnomer. What we are really doing is using the assumption that a pH electrode's output voltage (whatever shape it is in) reponds linearly to changes in pH and temperature and then comparing (really interpolating) voltage and temperature readings for the test solution (mash) to the known pH's of two buffer solutions. Here's a tentative "protocol" for this experiment. Don't just leap in and start measuring yet (unless you really want to) but rather let's let a little time go by to let interested parties (i.e. potential participants) comment on or question what I've proposed. If you think you would like to participate, please drop me a line and describe your meter and electrode. Required Equipment: Electrode: There are a couple of requirements for the electrode. First, it must be able to withstand the heat of the mash (electrodes containing calomel will be destroyed at about 70 C (158 F)). Second, its filling solution should only contain potassium chloride (in particular it should not be the commonly used potassium chloride plus silver chloride). Silver can react with the proteins in beer and can cause reading errors. Meter: There are lots of meters available and lots of combinations of features. To put all contributors on an equal footing irrespective of meter "bells and whistles" for this experiment we want only the ability to read millivolts and nearly all meters have this capability. It is desireable that the meter read to 0.1 mV as this corresponds to nominally 0.0016 pH. Another important feature is that the meter's input impedance be high relative to the electrode's resistance. It may be difficult to determine the input impedance of your meter as not all manufacturers put that number in their spec sheets. Buffers: Buffers should be NIST traceable and certified to within plus or minus 0.02 pH. I've used this spec since most buffers you can buy meet this. pH 7 and pH 4 buffers are required and should be made up fresh with deionized water before each brew session unless pre-mixed buffers are used. Pre-mixed buffers will preferrably be those which are sold in individual pouches. Bottled pre mixed buffers should be new and particular care must have been taken that pH 7 buffer has not been contaminated with pH 4 buffer (and vice versa) as by failure to rinse the electrode when moving it from one buffer to another. The integrity of the buffers is absolutely essential to the success of the experiment. The two buffers are the ends of a pH "ruler" and pH measurements made with bad buffers will be as worthless as distance measurements made with a yardstick which is several inches too long or short. Thermometer: A good thermometer readable to 1 degree (Fahrenheit or centigrate) is required to measure the temperature of buffers and samples. The temperature sensors built into pH electrodes are OK. Wash bottle: This is ideally a squirt bottle filled with deionized water which is used to wash off the electrode and thermometer (if it is separate from the electrode) each time the electrode is put into a new buffer or test solution. If a squirt bottle isn't available, put some distilled water (about a buck a gallon from the drug store) in a glass and dunk the electrode. Discard this rinse, rinse the glass with a small additional amount of distilled water, and then refill it with more distilled water for the next rinse. Beaker or glass: This is the container into which you will fill the mash test sample. It should hold enough mash that it will not coll so quickly that you can't get a temperature stable reading. -MORE- Return to table of contents
Date: Wed, 06 May 1998 16:52:42 -0500 From: "A. J. deLange" <ajdel at mindspring.com> Subject: pH Experiment - Procedure Procedure Here are the steps in the procedure. Data should be reported on the data sheet which is in a nearby posting. 1. Prepare fresh buffers or let pre-prepared buffers come to room temperature. 2. Calibrate your meter using the manufacturer's instructions. This involves putting the electrode into each of the buffers in succession. Be sure to rinse off any storage solution before entering the first buffer and then rinse the first buffer before going into the second. Shake or blot rinse (don't wipe) water. 3. After calibration (or as part of it if your meter allows) measure and record (on the data sheet) buffer temperature and millivolt readings for each of the two buffers. Be sure buffer millivolt readings are stable before recording. 4. Measure the pH of the water you are brewing with and enter the reading on the data sheet.. 5. If you know the alkalinity and hardnesses of the brewing water report that data on the data sheet. If calcium and magnesium hardness are known separately report total hardness. Specify whether hardness data is "as calcium", "as magnesium" or "as calcium carbonate". 6. Record grist composition i.e. how much of each grain type. Give maltster, and specify type e.g. Paul's Crystal, 50 L 1 lb. 7. Measure pH at one or more points in the mashing process. Wait a few minutes after doing things like doughing in or returning a decoction. Use a separate data sheet for each set of measurements. Start by withdrawing a few hundred mL of mash in a glass or beaker. 8. Rinse the pH electrode and thermometer and insert into the mash. Monitor the mV reading. 9. Move the electrode slowly and uniformly through the mash while watching the mV reading. IT MUST BE STABLE. When the reading is stable record it and then switch the meter to pH mode. Record the pH reading. Record the thermometer reading (make sure it is only touching the mash and not the beaker or glass). 10. Cool the mash sample as by placing the beaker in cold water. After a few minutes, stir the sample thoroughly and check its temperature. Try to get a handful of temperatures between mash temperature and room temperature. We'd like at least 3 and 4 or 5 are better still. 11. Repeat from Step 9 until room temperature is reached. 12. Thoroughly rinse the mash from the electrode and thermometer and then measure mV and temperature of the two buffers again being sure to rise before moving from one buffer to the other. Record the results on the data sheet. If you are going to do another set of measurments at a later stage in the mash, don't repeat the buffer measurements at the beginning of the new measurement set unless more than an hour has passed. -More- Return to table of contents
Date: Wed, 06 May 1998 17:01:14 -0500 From: "A. J. deLange" <ajdel at mindspring.com> Subject: pH Experiment - Data Sheet Data should be reported on this data sheet for consistency. Copy and paste a copy of the data sheet for each set of measurments you report. For example, if you do pH measurements at the return of the 1st and second decoctions use a separate sheet for each of those sets of measurments. Style of Beer: Length: Grist Composition: WATER Source; treatment: pH: Alkalinity: Hardness Total: Calcium : Magnesium: pH Meter Make: Model: Electrode Make: Model: Age: BUFFERS Manufacturer: Form (i.e. pouch, pre-mixed...): pH 4 Buffer pH 7 Buffer Temp.: milliVolts: Temp.: milliVolts: Temp.: milliVolts: Temp.: milliVolts: Mash Step (e.g. single infustion rest, after return of 1st decoction): Temp.: millVolts: pH: Temp.: millVolts: pH: Temp.: millVolts: pH: Temp.: millVolts: pH: Temp.: millVolts: pH: Temp.: millVolts: pH: pH 4 Buffer pH 7 Buffer Temp.: milliVolts Temp.: milliVolts: Temp.: milliVolts: Temp.: milliVolts: Return to table of contents
Date: Wed, 06 May 1998 23:40:29 GMT From: marnold at netnet.net (Matthew Arnold) Subject: Oatmeal Stout / Wisconsin Homebrew Clubs Seeing as things are kind of slow on ye olde HBD, I thought I'd ask these questions. I'm planning on making an Oatmeal Stout with 7 lbs pale ale, 1 lb Roasted barley and 1/2# oatmeal. Is this enough to give me that nice sliky smoothness? How much more dare I add before I need a beta-glucan rest? 1/2# in this recipe = ~6% of the grist. - ----- Attention Wisconsin Homebrew Club members! I'm trying to get a listing of all the WI clubs on our website (see address in my .sig). Check out our listing at http://www.rackers.org/clubs.html I've only found three others (Madison Homebrewers and Tasters Guild, Sin City Sudzzers, and Washington Heights Brewery) so far. I'd also like to look into the possibility of a WI club alliance of some sort (we tossed this idea around for a while at a recent meeting. What do you think? Thanks, Matt - ----- Webmaster, Green Bay Rackers Homebrewers' Club http://www.rackers.org info at rackers.org Return to table of contents
Date: Wed, 06 May 1998 19:04:32 -0600 From: Kevin TenBrink <tenbrink at jps.net> Subject: Hop Farming Hello- I have a question for all the home hop farmers out there. I have some 2nd year vines in the ground that are doing quite well....almost 12 feet long already! My questions are: 1) I keep getting little hop shoots sprouting out of the ground, some as far away as 3 feet from the original planting area. I keep cutting these back but I am wondering if they will ever stop sprouting or if there is something I can do to make them stop sprouting. 2) There is a chance I may be moving this summer from Utah to MI. Can I dig up and take a root cutting in the middle of the summer and replant when I arrive in MI to start establishing the root base for next year? Thanks-- Kevin Nine Inch Ales Homebrew Club Salt Lake City http://www.jps.net/tenbrink/nineinchales.htm Return to table of contents
Date: Thu, 07 May 1998 10:59:38 +1000 From: John Coulter <jac at mira.net> Subject: Stout head retention As a long time lurker, and Aussie home brewer, I need some help from the experts. My Guinness style stout, made with extract and steeped flaked/roast barley tastes and looks just the way I like it...almost. My nitrogen/co2 mix keg set-up and stout faucet pours a fine head, a bit foamy at times, which eventually results in a half inch head, looks perfect but then it disappears within five minutes, and doesn't taste as thick/creamy as a well poured guinness. I've tried doing a protein rest for the flaked barley, adding pale malt grain but it didn't help. Tried adding wheat to partial mash and that didn't either. My questions are: 1. Could using bleach steriliser be a contributor? ( I rinse 2 or 3 times) 2. Will using a carbonation stone, as someone suggested, increase the amount of nitrogen dissolved, and provide smaller bubbles to keep the head alive. Does anyone know if Guinness nitrogenate their kegs before they ship them or only use it to serve? 3. Have I reached the limits of extract brewing and can only improve the head by going to full-grain? 4. Does the quality/grain size of the flaked barley make much difference? 5. Any other ideas/suggestions? BTW the digest's great. I went from being an unhappy kit brewer to an almost happy, perfectionist, extract brewer with a laundry full of kegs, gas tanks and a hole in my pocket. Private E-mail fine. John Coulter jac at mira.net Return to table of contents
Date: Wed, 06 May 98 21:24:56 PDT From: "George De Piro" <gdepiro at fcc.net> Subject: Is my malt ruined? Hi all, I'm just finishing up a 1.5 week home malting project. I've made Pilsner, light and dark crystal, and Munich malts. Some chocolate malt will be made from the Munich malt in the very near future. All of the malts taste good, except for the Munich malt. It was also the most challenging to make, so it is no surprise that the outcome seems less than stellar. It has a quite pronounced acrid taste in the finish. It smells sweet and malty, but a bit too toasty. The color is a touch darker than Weissheimer Munich malt, too. I know, it seems an easy diagnosis: I over kilned it in the final stages. Of course it isn't that easy, though. I actually kilned it cooler and shorter than recomended by Kunze. Could it be the uneven heating in my oven? Is it that young Munich malt is supposed to taste a bit rough? Is my malt ruined?! If you haven't tried home malting, you don't know the fun your missing. I really enjoyed getting up at 2 am to check on the malt in the oven! You really develop an understanding of the whole process, too. For those who may be intimidated, Pilsner and crystal malt are actually pretty easy to make. If you are ever really searching for something to do, give it a shot! In the old days, crystal malt was made by steeping finished pale malt until a moisture content of ~45% was reached. You should change the steep water quite often to avoid souring of the malt if you do it this way (lest you make acid malt). Once the malt is appropriately wet, you cover it and heat it to as close to 145-160F as you can to saccharify it (just like mashing). After a couple of hours it will be noticeably sweet and somewhat darker (keep an eye on it if you are trying to make light crystal). You can then uncover it, let it dry, and raise the temp anywhere from 170F to 350F to make the color crystal you want and dry the malt. Easy! Have fun! George De Piro (Nyack, NY) Return to table of contents
Date: Wed, 6 May 1998 18:38:09 -0700 From: Hugh.Hoover at software.com (Hugh Hoover) Subject: DO and mixing While cursing my empty O2 container, and thankful that I'd sanitized my aquarium stone, I was thinking about the aeration process. Most of the actual transfer of gas into the liquid happens at the bubble interface (I think), which mostly is in the foam on top... This makes me think that for effective aeration, the wort has to be mixed during the aeration. I've observed that when using air (and 30 mins of aeration) I get pretty good starts, but w/ O2 (~2 min), sometimes I don't. Makes me think I should mix when using O2 (or use an inline stone). The airstone appears to put out sufficient volume to cause some mixing in the primary, plus working for 30 mins probably gives it time to set up a mixing pattern. Anybody done any testing of DO vs mixed / not mixed? Also, what's a reasonably volume of 02? Hugh Hoover PetaPint Brewery Return to table of contents
Date: Wed, 06 May 1998 19:22:11 -0600 From: Kevin TenBrink <tenbrink at jps.net> Subject: FWH extract recipes A question regarding FWHing extract with specialty grain recipes. If I want to try this, do I add the flavor and/or aroma hops to the sparged specialty grain soak water as I am bringing it to a boil but before I have added the extract? Do I remove the hops as the wort starts to boil or leave em in the whole time? Thanks for the help Kevin Salt Lake City Return to table of contents
Date: Thu, 07 May 1998 06:28:33 -0700 From: "S. Wesley" <Wesley at maine.maine.edu> Subject: Stainless Conical Fermenter Dear Jim, You may be able to purchase small cylindroconical fermenters from Pierre Rajotte's Company. I don't remember the name off hand, but I've seen a number of his 2 barrel fermenters in use in small breweries and I've heard that he makes smaller ones. If you can find a copy of this month's "American Brewer" Magazine he has an article on continuous fermentation in which he mentions the name of the company. Sticker shock may be a problem, so here is an alternative. I've been using 20 gal plastic barrels as fermenters for a while now with good results. I bought about ten of them from Modern Brewer in Boston for $19 each. They had been using them as fermenters in their commercial brewing operation. Unfortunately I belive they sold out of them when they sold off their BOP equipment, but they are not too hard to come by. Lots of people in Maine use them to collect sap for maple syrup manufacture. One guy told me he gets his used from dairy farmers, apparently they originally contained "teat dip"! Just last night I was driving home from work and I saw a few sitting by the side of the road. The guy who was throwing them away brought them home empty from the local hosptial where they originally contained an instrument sterilizer. You may also be able to find them at places like Grainger or McMaster-Carr. The fermenters have two 2.5" threaded openings in the top and a double handle which is rugged enough to lift the fermenter safely when it is full, although, they are, of course, rather heavy. They come with caps which have a rubber gasket which forms an air tight seal when screwed in properly. The caps can be drilled out to accomodate whatever gas release you want to use. I've rigged up a pulley system in the basement to lift the fermenters gently into the air for transferring. A racking cane made out of .5" copper tubing bent into a J at the top and bottom allows for surprisingly rapid transfer without the hassle of sanitizing pumps, or the accompanying agitation and loss of CO2. Regards, Simon A. Wesley Return to table of contents
Date: Thu, 7 May 1998 07:57:35 -0400 From: "David R. Burley" <Dave_Burley at compuserve.com> Subject: Acetaldhyde Brewsters: AJ DeLAnge gives a fine dissertation on the thermodynamics of alcohol oxidation using the Nernst equation. Nernst of course assumes there is an equilibrium situation. In the absence of that assumption, it is not correct that the higher the voltage, the more product you get. In the world of kinetics if you get a product and there is no back reaction, one only needs to get over the hump to form product permanently, so a minimum potential energy ("forward voltage") is all that is needed. Also, acetaldehyde is a major component in sherry along with lots of other aldehydes. Acetaldhyde is largely responsible for the disappearance of the anthocyanins from red wines used to make sherry as the acetaldehyde formed by the air oxidation of alcohol. Acetaldehyde reacts with the anthocyanins and the complex precipitates. Acetaldehyde also reacts with ethanol to produce an acetal. As sherry ages other aldehydes such as iso-valeraldehyde and higher molecular weight ones come forth and produce the classic aromas and taste, but acetaldehyde is still there and is a major taste contributor. Perhaps in low concentrations acetaldehyde in Budweiser tastes like green apples. - -------------------------------------------- Keep on brewin' Dave Burley Kinnelon, NJ 07405 103164.3202 at compuserve.com Dave_Burley at compuserve.com Voice e-mail OK Return to table of contents
Date: Thu, 7 May 1998 08:04:49 -0400 From: Bill Holman <jwh7k at avery.med.virginia.edu> Subject: SABCO mash kettle info wanted I would like some info from users of the Sabco mash kettle. How is the perforated stainless steel false bottom supported, ie how is it kept off the rounded keg bottom? Has anyone had the false bottom collapse from the weight of the grains/water or from use in a RIMS system? Overall, have you been happy with the kettle. Any comments or criticism would be helpful. Post answers to this newgroup or email me. Thanks! Return to table of contents
Date: Thu, 7 May 1998 09:34:33 -0400 From: Jeff Renner <nerenner at umich.edu> Subject: Dryhopping "Kris Jacobs" <jtsnake at mail.net-link.net> wrote: >I dropped two EKG plugs into each keg. Now, of course, I >get hop particles out my tap into my glass. First off, Kris, you used a whole lot of hops. Those 1/2 oz. plugs were originally designed to dryhop a cask of beer, although I can't recall exactly which of the many English sizes that was (certainly bigger than 5 gal.US). I've also read of an old brewery that used one handful of hops per cask, and it was specified that this was the hand of a small woman. They would stuff them in the bunghole using a stick and funnel. The hops do settle out and only an occasional leaf will come through at this lower rate, but as you point out, this is an annoyance, and they can even clog the tap. Much better to use a hop bag, but, as you suggested, it's too late for that. Rather than transfer the beer, I'd suggest getting a couple of stainless pot scrubbers, boil or otherwise sanitize them, remove the dip tubes of your kegs and tie the scrubbies on the ends of the tubes. This should filter the hops pretty effectively without clogging. Then get set for some pretty powerful dry hop character as time passes. Jeff -=-=-=-=- Jeff Renner in Ann Arbor, Michigan c/o nerenner at umich.edu "One never knows, do one?" Fats Waller, American Musician, 1904-1943. Return to table of contents
Date: Thu, 7 May 1998 15:32:33 +0200 From: "Dallas Dahms" <ddahms at nbs.co.za> Subject: South African Homebrewers I am looking for somebody who is a home brewer, living in SA who will be able to assist me and my Father in our search for the right equipment to start our own home brewing. If you are able to help me out, I would really appreciate it. Many thanks Dallas Return to table of contents
Date: Thu, 7 May 1998 10:13:34 -0400 From: "Henckler, Andrew" <ahenckler at findsvp.com> Subject: Evaporation Rates >Date: Wed, 6 May 1998 16:23:32 -0400 >From: dbgrowler at juno.com >Subject: kettle evap rates > >Troy brings up issues that have caused some serious navel gazing here in >my brewery. For many years, I happily boiled the bejesus out of my wort, >7 gal down to 5.5 over 90 minutes, enjoying my high alpha utilization, >excellent kettle break, and award-winning finished beer. After reading An >Analysis of Brewing Techniques, I, too, started worrying. I asked several >professional brewers about it; I can summarize their replies as "I >dunno." Then I went back and looked at my logbook. Though I brew plenty >of beers of all types and colors, the medal- and ribbon-winners were all >dark beers. Hmm. Reviewing score sheets on lighter beers showed some >indefinite remarks like "watch sanitation" with no specific off-flavor >mentioned, incorrect guesses at the yeast strain used, fermentation >temps, pitching rates, etc., which is quite in line with Dr. Fix's >observations. It appears that the effects of excessive thermal stress are >subtle for my system, such that they are not noticeable (or more in line >with the flavor profile) in the heavier, maltier beers. I've since brewed >two light Munichs serially, the second one with a less vigorous boil, but >otherwise unchanged. The results? I dunno... A partially covered boil >could be the ticket, but I foresee a learning curve perfumed with the >acrid smell of caramelized sugar. I think the key phrase in Fix's book is >"find a balance"; balance between adequate kettle reactions and thermal >stress, and also between attention to detail and a relaxed mental >attitude. > >Mike Bardallis Hello to all, especially Mike: I think that a more tightly controlled experiment might be in order here, unless Mr. Fix or some of our resident experts can give us some solid grounds for concern over evaporation rates (come on George de Piro, whip out those nice Siebel textbooks). Lighter beers are tougher to brew well because everything stands out. That means if you had only a tiny bit of difference in your bacterial counts, etc., the flavor could be noticeably different between batches, thereby confounding any attempts to see differences in thermal loading effects. You will also get different hop utilization, protein coagulation, etc. between a lightly boiled and heavily boiled batch, so it will be tough to compare two batches for thermal loading effects, ceterus paribus. As a highly anecdotal side-note, I use an afterburner style cooker with 90 to 120 min. boils even on lighter beers and my lighter beers actually tend to do better in competitions than the darker ones. Happy boiling! Andrew P. Henckler Senior Research Analyst Industrial Products & Services Practice Strategic Consulting & Research Group FIND/SVP-THE BEST PEOPLE TO FIND THE ANSWERS 625 Avenue of the Americas New York, NY 10011 Tel: (212) 807-2754 Fax: (212) 807-2782 E-mail: ahenckler at findsvp.com Web: http://www.findsvp.com Return to table of contents
Date: Thu, 7 May 1998 10:22:12 -0700 From: George_De_Piro at berlex.com Subject: Boiling and evaporation rates Hi all, Regarding kettle evaporation rates > 10% per hour, Troy writes, quoting Scott: "This is a typical Fix'ism; he makes a statement and then backs it up with nothing. The only negative from a stronger boil that I can think of is a greater energy ($$) usage." Talk about saying things without having anything to back it up! However, Scott is partly correct: higher energy costs are one big reason for keeping boiling times short. There are others, though, that are very important: 1. Caramelization and darkening of the wort are NOT always purposes of boiling! There are many styles of beer where this is detrimental (any pale beer). In fact, a major advantage of high-temp, pressure boiling is that the boil time can be *greatly* reduced, thus minimizing the amount of wort darkening that occurs. Hot break formation and alpha acid isomerization occur in 3-5 minutes at temperatures around 145C (293F). (That's not a misprint; three to five minutes.) The caramel flavors produced in the kettle are not appropriate in light beers, and may be what Fix is talking about. This fits nicely with Mike's experience (his dark beers taste better than his light beers given the same boil parameters). 2. If you have to boil off 20% of your wort to reach your target gravity, you may be oversparging. While you may be realizing great mash efficiencies this way, you may be negatively impacting the flavor of your beer because of increased phenol extraction during the sparge. This could cause astringency in the final product, and some beer evaluators may attribute it to a sanitation problem. Commercial brewers, with their concerns about efficiency and $$$, will sacrifice some extract rather than spend a fortune in time and $$$ boiling all that extra water off. 3. Too long of a boil can actually cause hot break to redissolve into the wort, or break it up into smaller flocs that are more difficult to remove. Neither situation is desirable. 4. Too long/intense a boil can actually cause sugars to revert back to their starchy origins! I'm not sure how long of a boil that would take, but Dr. Powers at Siebel mentioned this. Anybody care to talk about how long this would take? So, there are some solid reasons to avoid overly long and/or intense boils. I'd like to hear some more, particularly from Dr. Fix. Have fun! George De Piro (Nyack, NY) Return to table of contents
Date: Thu, 07 May 1998 07:55:59 -0700 From: michael rose <mrose at ucr.campus.mci.net> Subject: Boil rates and evaporation There has been a lot of discussion lately about boiling and rates of evaporation. i.e. comparing a partially covered home kettle to a pro's domed shaped kettle. The pro's have a blower (don't know the technical term for it) on top of the flue. The blower exhausts the steam from the kettle but it also creates a slight lowering of the air pressure which increases the rate of evaporation. I think. Anyway, I'm sure the blower interacts in many more ways than we are taking into consideration. I think :^) - -- Michael Rose Riverside, CA mrose at ucr.campus.mci.net Return to table of contents
Date: Thu, 07 May 1998 08:01:54 -0700 From: Charles Hudak <cwhudak at adnc.com> Subject: Covering the boil Regarding covering the boil..... "Professional" kettles are not really "covered". I'm assuming that you are referring to the 'onion dome' on top of the kettles which channels the steam and other volatiles out of the building. This is so the humidity level doesn't go through the roof in the brewhouse. Usually there is active ventilation (a blower on the roof) which ensures that the steam goes up the stack and not out the manway. This actually increases the rate of evaporation somewhat. I don't see any reason to try to achieve an evaporation level of exactly 10%. My advice is to keep track of your brewhouse parameters so that you know what your evaporation loss is and adjust your recipes and your runoff volume accordingly. That is what the "Pros" do. They have no (or very little) control over evaporation losses. They is what they is. FWIW, I am no longer a "Pro". On Friday, I reverted to amateur status. Got a job offer that I couldn't refuse: lots more $$, great benefits, quality oriented....all the things missing from my beermeistership. Hey, now I can afford to buy that pico system and start doing lots more homebrewing..."Kick ass" L8rz C- Return to table of contents
Date: Thu, 7 May 1998 11:14:00 -0700 From: George_De_Piro at berlex.com Subject: Beer Evaluation Hi all, Capt. Marc asks about what will happen to his beer when he sends it to a contest. He wonders if he will get feedback even if he doesn't place, and is concerned about proper handling and serving of his beer. When your beer arrives at the contest shipping point, it should be stored in a cool, dark place. Most people try to run good contests, but there are always exceptions. I heard about a recent contest where the beers were stored outdoors in the winter sun. That's a big "Oops!" The day of the contest the beers are brought to the contest location (if they are not already there) and served to the judging panels, which each consist of 2 or 3 evaluators. The beers are broken up into flights depending on the style of beer and the number of entries. Very often stouts are broken into two or more flights (evaluated by 2 or more panels) because there are so many entered. Conversely, Vienna, Oktoberfest, and Alt are often lumped into one flight. In this way an attempt is made to give each panel a reasonable number of beers. Overloading the judges only reduces the quality of their feedback because of palate fatigue and time constraints. The beers may be served too warm or too cold, but rarely "just right." I often carry a cooler with me that I can fill with hot water to warm up freezing-cold samples. It is easier to evaluate a beer that is too warm than too cold. I don't think there are many judges this anal, though (which is unfortunate). The evaluators fill out a score sheet for every entry, and the participant will receive these in the mail whether or not they placed. The judges should not talk about the beer until all comments are written. This way, one judge cannot influence anothers perceptions. That is why you will sometimes get sheets back where it seems like the judges were tasting two different beers; we're all human, and some people are more sensitive to some chemicals than others. The usefulness of the judge's comments is dependent on the quality of the evaluator and the contest organizer. It is up to the organizer to take care of the following: Is the beer served at close to the proper temperature? Is the right beer being served in the category it was entered in? Are there enough judges to handle the number of entries? Is the beer stored properly prior to the contest? It is up to the judge to prevent palate fatigue by drinking plenty of water and taking small sips of the sample. Sobriety is key! Bread should not be used as a palate cleanser; it has taste and aroma!!! The starch in the bread can actually clog the larger taste buds at the back of your tongue (the bitterness receptors). I recently judged at a professional competition at the Culinary Institute of America. They put big baskets of wonderful, crusty, buttery-smelling bread on each table. Another big oops! Have fun! George De Piro (Nyack, NY) Return to table of contents
Date: Thu, 7 May 1998 12:04:30 -0400 (EDT) From: BR Rolya <brrolya at cs.columbia.edu> Subject: Trip from NYC to GABF in Baltimore The following is a region-specific post; I apologize in advance for its limited appeal. On Saturday, May 16, the Malted Barley Appreciation Society (a NYC homebrewing club) is renting a bus to go down to the Great American Beer Festival in Baltimore. We will leave Manhattan at 6:45 AM and arrive in Baltimore in time for the 12:30 pm session. We will leave Baltimore at around 8:30 pm. The cost is $30 for round-trip bus fare. In addition, you must purchase your own ticket for the GABF from the AHA (tel. 888-822-6273) for $25. AHA members can also request a voucher for the members-only session that begins at 11 am (we will arrive in time for that). As an added attraction, we will premiering the infamous "Steinbier Incident" video starring George de Piro and directed by Bill Coleman! For more information, or to reserve your seat, contact Bob or myself at 212-989-4545 or triage at mindspring.com - BR Rolya Triage brrolya at cs.columbia.edu Return to table of contents
Date: Thu, 7 May 1998 20:40:09 -0700 From: Troy Hager <thager at bsd.k12.ca.us> Subject: Boil evaporation Tony, You say: Another solution would be to add boiling water to the kettle to keep the wort level at the desired level. i.e. 5.5 Gallon initial vol. then add boiling water when the level drops below 5 Gallons. ___________________ I don't know if this is a solution. What Fix is discussing in their book is the negative effects of excess thermal loading, not of excess loss of water. I think they are saying that the evaporation rate (loss of water) itself is not the problem(though a good reference) - it is the excess heat and all of the ramifications of this to the boiling wort that is the cause of negative affects... Troy A. Hager 2385 Trousdale Drive. Burlingame, CA 94010 259-3850 Return to table of contents
Date: Thu, 07 May 1998 09:39:32 -0700 From: Jeremy Bergsman <jeremybb at leland.Stanford.EDU> Subject: 10% rule Regarding the discussion about evaporation rates: I don't have the Fix book in front of me but I recall that when Fix mentions that evaporation should be <15% it is int he context of a discussion of heterocyclic sulfur compounds, no? If you look at the flavor descriptions of these, many are undesirable. I believe that you want to limit formation of these and that is why you want to limit "thermal loading." As another data point I don't feel my boils are all that vigorous and I reduce 12.5 gallons to 10-10.5 gallons in a typical batch, and that is slightly covered. I don't see how you can get a good boil and only lose 10% unless you are returning a lot of the vapor to the pot. If this is what you are doing, it seems to me that the thermal loading is the same as letting it evaporate and either starting with more water or topping up after the boil. On a related note: I think that all this concern over covering the boil is BS. DMS is incredibly volatile. Unless you're using a pressure cooker I don't see how you could keep it in if you wanted to. I used to just crack the lid on my boils when I used an electric stove and I didn't have excess DMS (IMO). I recently did the experiment suggested here a few years ago and collected the condensate from my lid during the boil and tasted it. Water. - -- Jeremy Bergsman jeremybb at stanford.edu http://www-leland.stanford.edu/~jeremybb Return to table of contents
Date: Thu, 7 May 98 10:32:08 -0700 From: brian_dixon at om.cv.hp.com Subject: Re: Re-started fermentation in the secondary Arnold asks about apparent restarting of the fermentation after racking to a secondary, and I believe, adding dry hops. Observations that I've made in the past from normal and from one particular infected fermentation have lead me to believe the following conclusions about increased airlock burbling after racking: - Dissolved CO2, and CO2 trapped or 'stuck' to suspended yeast can be released during the racking process. The result is increased bubbling of the airlock and yeast falling out of suspension. This is normal and can be ignored unless the bubbling lasts a long time. - Primary fermentations that are not complete, but happen to have a leaky fit around the stopper and airlock (or bucket lid) often appear to be done or slowing, but then increase after racking. What really happened was that after racking the leaks in the system were fewer or gone and the CO2 is now going through just the airlock. Knowing how long the beer's been in the primary is your primary clue here, plus any SG measurements you may have taken. - Infections (yikes!) are usually indicated when the increased bubbling in the secondary _continue_ longer than expected. For example, if you know enough time has passed to make you sure the primary is complete (longer than about 4-5 days), and if the increased bubbling in the secondary has not slowed within a few hours, then it's possible that you have an infection. If the bubbling rate continues to increase, and then lasts for a long time (a few days or sometimes longer), then an infection may also be present. To understand what is happening, consider the fact that the 'good' yeast that we conduct our fermentation with is fairly constrained in what it can metabolize as compared to wild yeasts or bacterias that are present in nature (only some of which will produce a gas during metabolism). Wild or mutated yeasts in particular can digest more complex sugars and starches than beer yeasts. When an appropriate bacterial or wild yeast infection, or a mutated beer yeast exists in your wort (shit happens), then the 'fermentation' can continue long after a normal fermentation would finish because a longer more complex list of 'food' is being digested out of your wort. Other symptoms that provide clues here are taste, mouth feel, and appearance. Obviously everyone knows about the rings and things that are visible indicators of infections, but what about loss of head forming capacity? If your beer has the ability to form a nice head of foam on bottling day, but has no capability to do the same a couple of weeks later, and you saw some kind of extended fermentation going on, then it is likely that you had an infection that was capable of digesting medium and high molecular weight proteins (and probably starches). The beer will often taste/feel thinner after it's been in the bottles for awhile, and there will often be off-flavors present (sourness, 'stale'ness, 'odd somethings' etc). And sometimes, these off flavors change or go away somewhat over time. Wild yeast infections tend to peak in sourness at around 8 weeks in the bottles, then it diminishes a bit but doesn't go away completely. Don't ask me how I learned about all this, but a certain experience with plastic fermenters and one particular Dusseldorf style Altbier might be good hints to start with... Good luck, and I hope you don't have an infection! I gave up on my equipment after some thorough sanitizing efforts and a couple more brews failed to help. I switched to all glass fermenters and bottle out of a carboy with a simple siphon system, e.g. no plastic bottling bucket. And I have no issues with replacing hoses, racking canes, and bottling wands on a regular basis! Since that change, I have had no further problems with infections. Brian Return to table of contents
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