HOMEBREW Digest #4658 Tue 23 November 2004

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  Re: Another question about copper ("Craig S. Cottingham")
  Lagering (David)
  Freezing Beer (Alexandre Enkerli)
  re: distilling barley wine? ("Spencer W. Thomas")
  soluble copper, distilling bad beer ("Dave Burley")
  distilling, pH meters, CFCs, Alaska, ("Marc Sedam")
  re: IBU's and Cooling ("Jim and Shelly Hansen")
  Late Hop additions (Kevin Pratt)
  IBU's and Cooling ("zuvaruvi")
  Re: Predicting IBUs: Immersion vs counterflow chillers (val.dan.morey)

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---------------------------------------------------------------------- Date: Mon, 22 Nov 2004 22:06:49 -0600 From: "Craig S. Cottingham" <craig at cottingham.net> Subject: Re: Another question about copper On Nov 21, 2004, at 23:41, "Paul Fisher" <snapfisher at att.net> wrote: > When I use a copper immersion chiller, it always comes out of the wort > sparkling clean. So where did the tarnish go? In the beer? Yes. > I figure this > has no real effect on the beer, but what is the tarnish? Is it just > oxygen > bound up with the copper that gets scrubbed off by the boiling? Yes and no. The bulk of the discoloration is cupric oxide, CuO. It's insoluble in plain water, but dissolves readily in dilute acid -- as which wort qualifies. Thus, it's not so much the mechanical action of boiling as the heat and the pH of the liquid in which it's immersed. - -- Craig S. Cottingham craig at cottingham.net OpenPGP key available from: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x7977F79C Return to table of contents
Date: Mon, 22 Nov 2004 21:38:47 -0800 From: David <gates at island.net> Subject: Lagering I have never lagered before and I have a couple questions. Is there a minimum temperature to lager? My beer is sitting outside my front door and the ambient temperature changes from 4 deg C to 6 deg C. How long at low temperatures will it take to ferment? I am not in any hurry. Should I rack to a secondary at one point? Thanks for a great hbdigest. David Return to table of contents
Date: Mon, 22 Nov 2004 23:21:41 -0500 From: Alexandre Enkerli <aenkerli at indiana.edu> Subject: Freezing Beer Kevin Haborak suggested: > I definitely would not try to distill the beer using a pressure cooker. > Take the safe route and freeze it. Skim the ice off the top as it > freezes. And freezing has an interesting effect on beer. Of course, strengthening beer like might be illegal in some places (we're assuming Belize isn't one) but we all know "someone" who's done it and can tell of the results. The best way to describe it (according to "someone" who's tried it) is as incredible smoothness. Not surprising when you think of Eisbock but quite interesting when you try it (arhem, "when someone tries it"). "Someone" did it by mistake during a cold Canadian winter. Interestingly, the beer was still carbonated (or so I'm told). So, if you can, yeah, go for it! ;-) AleX in South Bend, IN [129.7mi, 251.5] Apparent Rennerian Return to table of contents
Date: Tue, 23 Nov 2004 08:45:20 -0500 From: "Spencer W. Thomas" <hbd-mod at spencerwthomas.com> Subject: re: distilling barley wine? One of our local brewpubs is also a micro-distillery (Leopold Bros.). He once made some "beer schnapps", but told me he did it only because "it was expected", and that it was pretty nasty stuff. (I'm not sure who "expected" him to do it.) I didn't get to taste it, so I can't give a first-hand report. Since his other spirits are (IMHO) pretty tasty, I have to assume that the nastiness came from the source material and not from the process. =Spencer in Ann Arbor, MI Return to table of contents
Date: Tue, 23 Nov 2004 09:35:16 -0500 From: "Dave Burley" <Dave_Burley at charter.net> Subject: soluble copper, distilling bad beer Brewsters: Paul asks whereforth goeth the copper tarnish on his chiller? Answer: It dissolveth in the acid brewe. Copper tarnishes by forming compounds with oxygen in the form of hydrated mixed oxides and hydroxides and carbonates. Even though the elemental copper metal is not soluble in acidic solutions these oxides are. Clean your chiller if you wish with white distilled vinegar or hydrochloric acid ( pool store or Home Depot or other building trade store) solutions before rinsing and then immersing them in your brew. But Yeast need a LITTLE copper to be happy, so the few molecular layers on your chiller probably won't do anything bad and may do some good. Copper salts will produce a metallic taste in high enough concentration. - --------- As far as distilling goes, most recognize that concentration of alcohol by any physical method - distillation or freezing is illegal without a license. That said, I don't think a little experimental work in pursuit of your hobby will upset Uncle Sam, unless you publicise it and continue it in a large way. That said, distillation is a potentially dangerous thing aside from the potential capture of wood ( methyl) alcohol and its poisonous and blinding effects. Alcohol burns with a practically colorless blue flame and will catch on fire in contact with a hot surface or flame. So don't be so careless as to try this in your house nor anywhere without a fire extinguisher. There are hobby books and websites devoted to this pursuit. A friend of mine was so foolish as to set up a small still in his business until I told him the Government can confiscate his entire property, car etc. if he is discovered. He decided that given the indiscreet nature of his friends, this probably wasn't the best way to proceed, especially since we live near "Dark Corners" SC, infamous home of moonshine stills in the old days and revenoorer activity, before auto racing took its place. You will probably find that a better route is to throw away the bad beer or to add yeast energizer to it and re-ferment it with some more S. Bayanus. One thing you have to be careful of is that sometimes a "champagne yeast " is actually S. Cerevisiae and not meant to be able to start up in high concentrations of alcohol and low nutrients. Acclimate the yeast by adding your nutrient charge and yeast to a small amount of beer diluted 50/50 with water. Then add the remaining beer as fermentation proceeds. You can bottle at this stage after adjusting the priming sugar concentration. Keep on brewin' Dave Burley Return to table of contents
Date: Tue, 23 Nov 2004 10:37:32 -0500 From: "Marc Sedam" <alechemist at bellsouth.net> Subject: distilling, pH meters, CFCs, Alaska, Re: Distilling barleywines Um...DON'T. If you had not added bittering hops you could have easily done this. I tried a distilled wort at the Weinstephan a few years ago and it was tasty. But remember that hop isomerization is effected by temperature and pH...and by subjecting the wort to boiling temps for the hour or so it takes to distill, you'll keep isomerizing the alpha acids, in addition to breaking up any of the remaining yeast cells (can you say 'yeast bite'). Someone had the brilliant idea of concentration through freezing. BRILLIANT! It will take longer and longer to do, but you can also stop the process whenever you like the flavor. Re: pH meters Given that I'm not brewing professionally, I don't feel the need to control pH to the hundredth of a unit (keeping in mind that it's a logarithmic scale, of course). HOWEVER, there's a happy medium to be had here. When I moved to Chapel Hill from New Jersey I found that some of my recipes changed a bit. I ordered the water analysis from my utility company and found Chapel Hill has very soft water, like Plzen. I got my hands on one of those Piccolo pH meters and did two things within a month: (1) made up small quantities of all the water profiles I might use (Burton, Munich, Dortmund) and checked with the pH meter to see if my pH matched what I should have gotten for these waters (it did); and (2) checked out how my beer behaved when brewing a standard pilsner grist (all pils malt), a standard pale ale grist (pale malt plus a pound of crystal), and a standard stout grist (pale malt plus lots of roasted barley). I took copious notes on how and when the pH changed and made sure to rigorously clean the probe between brews according to the instructions. Once the three brews were done, I had some idea of how other beers would behave using the same water. Sure the rest is guesstimates, but I got the benefit of doing all of the detailed analysis when the probes and calibration solutions were fresh. If I ever move, or my water ever changes sources, I'll go through the process again. Looking at pH for every brew in the HB environment strikes me as overkill, but good knowledge of how your brewing and water interact is still very important. Re: CFCs I'm sure some bitterness is contributed from late hop additions, especially if it takes 30 mins to drain the kettle. I usually use a pump to pull the wort through my CFC, so even 10 gallons of wort only takes 10 minutes. That cuts down on the effect. You also might consider waiting 10 mins before adding the aroma hops, such that the temp of your wort drops tens of degrees below boiling. That will also cut down on the bitterness extracted from aroma hop additions, since the physical movement of wort (in addition to the heat) during boiling the wort is one of the drivers of isomerization. Re: AHA meeting in Alaska (take this all in the good spirit in which it's meant) I think it's a great idea. Would I go...well probably not. But that's because it's difficult to convince SWMBO to allow me to use portions of my precious vacation to drink beer. I went to the Dallas meeting because she happened to be on a consulting gig at the time, and I'll likely go to Baltimore because it's so close I can drive. But the issue is vacation as much as it is anything. I probably represent the demographic that the AHA is looking to attract to these meetings (25-39 y.o., decent job, and my mom says I'm cute as a button) but I can't honestly say there's anything the AHA could do to get me to the annual meeting OTHER THAN HAVE IT IN A REALLY COOL LOCATION. Alaska would be one of those, certainly. As for the travel component, while I think the research done is good, it's misleading. BWI (Baltimore) is a Southwest Airlines hub and is generally one of the cheapest airports to fly in and out of. So comparing Anchorage to Baltimore isn't really fair to Anchorage. Compare Anchorage to...say...RDU (Raleigh-Durham) for a better look-see. Just for fun I went to Orbitz and looked at flights about six months from today from a handful of airports that I remembered the designations of (Boston, Newark, RDU, Atlanta, BWI, Chicago, Dallas, Kansas City, Seattle, Portland, San Francisco). All of the flights were between $500-$575, with the exception of Seattle and PDX (where you could find one for $300). So one could argue that if it costs the whole country the same amount of money to get to Alaska, it all washes out. Of course you also have to consider that every comparison is temporal, i.e. you may research travel costs during a fare sale or after one ends. I've helped put together professional conferences before and it's my experience that local costs are far, far more important than airfare. So if the hotels, restaurants, and car rentals are reasonable, the airfare can be a wash. If the only thing to worry about is airfare, then the conferences should always be held in the middle of the country since it's half-way to everyone. :-) I think if the AHA has a buffer in the account, that it's worth taking a chance. LET THEM PLAY! LET THEM PLAY! LET THEM PLAY! Cheers! Marc Sedam the southern side of Rennerian Return to table of contents
Date: Tue, 23 Nov 2004 10:54:34 -0500 From: "Jim and Shelly Hansen" <jnshan at execpc.com> Subject: re: IBU's and Cooling >I use an immersion chiller and feel that I am getting about 5 IBU's >more >than what Promash tells me I should get. I have discussed this with >several members of my club who have reviewed my recipes and >techniques. We >feel that the hot wort continues to extract IBU's , mostly from the >late >addition hops, until it reaches some magic temperature. Since I >chill the >entire wort at one time with an immersion chiller I am getting these >additional IBU's. I also employ an immersion chiller. My method is to remove the hops prior to chilling. I either tie a string on a hop bag for pellets or use a grain steeping bag for leaf hops. I have found that this reduces the "rough" bitterness I was precieving in my beers. This in addition to ph adjustment prior to boil, has given me a "cleaner" bitterness. Jim Hansen Waupaca Homebrewers Order J.M.S Hansen Homebrewery Wisconsin - -- "The mouth of a perfectly happy man is filled with beer." - Ancient Egyptian Wisdom, 2200 B.C. - -- CoreComm Webmail. http://home.core.com Return to table of contents
Date: Tue, 23 Nov 2004 08:45:43 -0800 (PST) From: Kevin Pratt <oh2bontv at yahoo.com> Subject: Late Hop additions Fred Johnson <FLJohnson at portbridge.com> SAID: > regarding late hop additions > and bitterness contributions. I must disagree with his > assertion that > the hops sitting in the hot wort will not contribute much > bitterness > after flame out. I believe isomerization is primarily a > function of > time and temperature. <snip> > Correct me if I am wrong, but > I believe they are dissolved or at least emulsified in > the wort. If it > takes 30 minutes to drain the kettle, your flameout > addition has just > become a significant bittering addition. Likewise, the > hops you added > at 30 minutes have now contributed close to their full > alpha acid > potential to the bitterness. There are several (like a dozen or more) factors that affect hop isomerization in wort. The vigor of the boil is just one of them. The less vigorous, the less isomerization. Therefore, once the boil subsides after flameout, utilization drops dramatically. Isomerization is a specific, direct chemical change in the humulone resins. Emulsification is where something can be bound to water through an intermediate chemical and mechanical process (like salad dressing). Hop Alpha and Beta acids are hydrophobic, meaning that they don't readily dissolve into water without some persuasion. So, late hop additions in hot, but not vigorously boiling wort do contribute minor amounts of bitterness, but if the wort is handled properly and the fermentation is good, the result is minor. More likely, DMS will result from a long chill than over bittering. The *perception* of bitterness is related to even more factors than isomerization. Attenuation, minerals, yeast population, trub removal, blowoff and more all affect the bittering perception. Ultimately the brewer should use the taste of the finished beer as a guide to adjusting ingredients and technique to the equipment used. Kev. Return to table of contents
Date: Tue, 23 Nov 2004 09:04:08 -0800 From: "zuvaruvi" <zuvaruvi at cox.net> Subject: IBU's and Cooling Fred: Consider 15 barrels of wort sitting in a jacketed copper. When wort is boiling, there are a lot of convective currents which keep things moving in the boil (obviously, otherwise a rolling boil wouldn't be called a "rolling" boil). Well, shut down the fire on 15 barrels and it takes a while for the temperature to budge off of 212, and even though the wort is no longer boiling, convective currents are still quite strong until the wort gets below 210. For this reason, most brewers wait a good 15-20 minutes before they can effectively whirlpool (a whirlpool doesn't work if convective currents keep carrying hot break and hops up off the cone that is forming bottom center). Point is, the bigger the batch, the longer it stays hot. Aroma hops added at knockout in commercial size batches stay at near boiling temperatures for substantially longer periods of time than could possibly occur in your five gallon setup, even using an emersion chiller. I doubt you are extracting more bitterness from your aroma additions than the big boys. FWIW, Chad Stevens QUAFF San Diego Return to table of contents
Date: Tue, 23 Nov 2004 20:17:28 -0600 From: val.dan.morey at juno.com Subject: Re: Predicting IBUs: Immersion vs counterflow chillers Fred asks how the cooling method affects bitterness. I too switched to a counter flow chiller about a year ago, but never consider adjusting my recipes. An interesting question, which prompted me to take a look at the subject using the existing approximations. Consider the following: 5 gallon batch OG 1.050 with three hop additions: 1 oz at 9% AA for 60 minutes 28.7 IBUs 1 oz at 5% AA for 30 minutes 10.7 IBUs 1 oz at 5% AA for 2 minutes 1.0 IBUs Total 40.4 IBUs Note, I have assumed Util% = 28.6*(1-e^(-0.024*t)), where t is time in minutes (this equation is the fit to the average of several utilization approximations). For gravity correct Cg = 1.295*(0.0036^(OG-1)) fit to the average of several gravity correction correlations. With counter flow chilling alpha acid is being removed during cooling (concentration of alpha acids per volume of wort remains unchanged). So as cooling progresses, there are less alpha acids to isomeric. Thus the numerator of the IBU calculation is affected. The effective mass of alpha acids should be proportional to the volume of wort remaining in the kettle. I've assumed the AA are "evenly mixed," as suggested in earlier posts. Performing the numerical integration, the adjusted results are: 1 oz at 9% AA for 70 minutes 29.7 IBUs 1 oz at 5% AA for 40 minutes 11.8 IBUs 1 oz at 5% AA for 12 minutes 3.2 IBUs Total 44.7 IBUs A 10% increase over the original calculation, with the latest hop additions affected more. But how much is this an increase over immersion chilling? As Fred points out, isomerzation is a function of time and temperature. In immersion chilling, the wort is gradually cooled. As the temperature drops, so does the effective utilization. Combining Garetz elevation/temperature correction with the standard atmosphere table and steam tables, I came up with the following correction for temperature: Ct = 0.022 * e^(0.018 * T), where T is temperature in degrees F Effective utilization is: %Uc = %util * Ct Temperature versus time can be estimated from the lump capacitance model: T(t) = ((Ti-Tc) * e ^ (ht/C)) + Tc Assuming that it takes 20 minutes to cool 5 gallons of wort from 212F to 80F using 55F water, the quotient h/C is approximately 0.09. Using the predicted temperature decay, one finds that Ct decreases quickly. Numerically integrating, the following adjusted IBUs were calculated: 1 oz at 9% AA for 60 minutes + cooling 29.6 IBUs 1 oz at 5% AA for 30 minutes + cooling 11.8 IBUs 1 oz at 5% AA for 2 minutes + cooling 3.1 IBUs Total 44.5 IBUs Very close to the counter flow results with a 10% increase over the original calculation and again late addition hops are more affected. So for this example, the predicted result from the counter flow process would be very similar the immersion cooled batch. I chose 10 minutes and 20 minutes for this example since these are commonly quoted times. Using these cooling durations, how much more bitterness is extracted from hops as a function of time from knock out? Below are the results I came up with: Time % increase Counter flow vs immersion chilling 0 4.93 5 2.24 10 1.38 15 0.96 20 0.72 30 0.45 45 0.25 60 0.15 90 0.07 Since there is no precise approximation for bitterness and knowing actual alpha acid content is questionable, I would suggest adjusting recipes for any addition is questionable. The various formula available will give more than 5% variation (see Zymurgy 1997 special hop issue! The contributions of late additions are more for flavor and aroma. To cut these back may be more detrimental than the slight increase in bitterness. More interesting to me is the temperature correction predicts that dry hops do increase IBUs! Consider 1 week at 60F: 10080 minutes => %Util = 28.6 (maximum utilization due to contact time) and Ct = 0.06, thus the corrected utilization is 1.8%. With some of the dry hopping schedules reported, this can be more significant than the effects of counter flow chilling. In general, dry hopped beers always seem more bitter to me than what the brewer quotes. The good news is we can always brew again if the results were not what we wanted, adjusting things up or down. Cheers, Dan Morey Club BABBLE http://hbd.org/babble [213.1, 271.5] mi Return to table of contents
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