HOMEBREW Digest #4934 Sun 22 January 2006

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  Re: You know it's been a while since you've brewed when... (Ben Hanson)
  Re. Increasing IBUs ("William Frazier")
  Low Alcohol output ("Tricia Simo Kush")
  Commercial beer suggestions ("GRANT STOTT")
  Aroma Hops and Bitterness (David Edge)
  re: converting a keg to a secondary fermenter ("C.D. Pritchard")
  yeasts attenuation/flocculation/storage ("steve.alexander")

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---------------------------------------------------------------------- Date: Sat, 21 Jan 2006 09:43:11 -0500 From: Ben Hanson <benhanson at verizon.net> Subject: Re: You know it's been a while since you've brewed when... You know you haven't brewed for a while when... you have a carboy of mead on the counter you made the year your 5 year old was born which has been clear and waiting to be bottled for the last 18 months........and it's the last thing you brewed. (Should be good though - made from my own bees' honey!) Ben Return to table of contents
Date: Sat, 21 Jan 2006 10:18:45 -0600 From: "William Frazier" <billfrazier at worldnet.att.net> Subject: Re. Increasing IBUs Russ - Consider a hop extract. Go to www.hoptech.com. They have some extracts that can be used just for bitterness. I have some but have not needed to use them yet. Bill Frazier Olathe, Kansas USA Return to table of contents
Date: Sat, 21 Jan 2006 16:58:46 -0600 (CST) From: "Tricia Simo Kush" <mpls at realmofzorcon.com> Subject: Low Alcohol output Hello all - first time poster, been reading for roughly a year (thanks to Joe M. in Seattle). I'm in Minneapolis and my husband and I have homebrewed for roughly ten years. We have a VERY basic setup and, for the most part, make some darn fine beer. Our most frequent struggles are with either low carbonation or low alcohol. The former issue we can work around with a hand-tap on the keg (CO2 has been a significant problem in the past, so let's not go there). The alcohol issue hasn't reared it's, uh, head in a while, but we were bit by it with our most recent batch. I can provide specific batch details, but I was hoping that the trick might be something more general, since it almost seems random in occurance. Our other batches of beer are nearly TOO high in alcohol (as in "our friends sleep over when we unveil a new batch"), so we are stumped. Here are a few details: We have switched to liquid yeast - no more dry. Here is the kit we usually make, with VERY wonderful and nearly predictable results: http://www.midwestsupplies.com/products/ProdByID.aspx?ProdID=3494 Here is another kit we enjoy and ALSO yields great results: http://www.midwestsupplies.com/products/ProdByID.aspx?ProdID=3317 (Yes, the kits show dry yeast - we ALWAYS upgrade.) This batch, however, came in so low that we call it "beer-flavored water". It tastes great but has no *zing*. http://www.midwestsupplies.com/products/ProdByID.aspx?ProdID=3554 Again, I don't want to toss out a lot of details unless the evidence suggests something more specific. Is a lackluster alcohol something that we should expect to see from time to time, or is there an obvious and reasonable cause for this? The newsletter has been terrific and the community is rich, so I am hopeful for some good suggestions!! ~ Trish K. Return to table of contents
Date: Sun, 22 Jan 2006 17:14:16 +1100 From: "GRANT STOTT" <gstott at iprimus.com.au> Subject: Commercial beer suggestions 3rd attempt to post after upgrading my computer. Have configured outlook according to the website suggestions so should work this time. A friend who is going to Portland Oregon in a few weeks time has offered to bring back a small selection of beers. The only beer I have tried from this area is Bridgeport IPA, which we both like. As only one decent American beer is available over here Sam Adams boston Lager. I don't think I will be offending anyone (If so I appologise as we are all entitled to our own taste) in saying otherwise we can only get Bud, Miller, Coors. What I would like are suggestions of good brews that are easily available in this area to put on a short list to bring back & try, & the ones we like best we will most likely try to brew in the future. Offline replies are most welcome. Send to gstottATiprimusDOTcomDOTau (should be obvious) Thanks, Grant Stott Geelong Vic Australia (where if reached 105`F today) Return to table of contents
Date: Sun, 22 Jan 2006 14:27:55 +0000 From: David Edge <david.j.edge at ntlworld.com> Subject: Aroma Hops and Bitterness Fred Johnson observed that some commercial micros have a single late addition. In the UK some certainly put a very small amount in early and 90% late. York Brewery for example makes very bitter beers this way. As Fred observes, the hops are sitting in hot wort for the hour or so it takes them to pump through the paraflow in their (I think) 20 UK brl plant. A big vessel will cool a lot less that a small homebrew kettle in that time. Immersion coolers are different - they cool the whole wort so isomerisation will be negligible after a couple of minutes - my wort comes down to 70 degC / 160degF very quickly. I spent ages the other day searching my notes from courses at Brewlab (Sunderland, UK) for a graph that showed bitterness extraction for kettle off hops. I can't find it but I seem to recall it could reach 80% compared to full boil, but I'll chase that up. We used to have a convention that hops added at 0 minutes were entered into Promash as 10 minutes if they steeped for some time. (We never add hops at 10.) It was just a guess. David Edge, Derby, UK Return to table of contents
Date: Sat, 21 Jan 2006 10:45:43 From: "C.D. Pritchard" <cdp at chattanooga.net> Subject: re: converting a keg to a secondary fermenter James Payne asked about converting a pin lock corny keg to a secondary fermenter. Cornies make great secondaries. I like them because you can pressurize them with CO2 to aid in transferring the brew. Not much in the way of modifications are need for use as a secondary. Just fit an airlock onto the gas disconnect or run vinyl tubing from the disconnect to a jar of sanitizer. Depending on how clear your brew is going into the secondary, you might want to cut off the liquid dip tube a bit to avoid sucking up dregs in the bottom of the keg. Better still, attach a flow diverter from a plastic racking cane to the end of the dip tube. Since the ID of the diverter is larger than the OD of the dip tube, I use a spacer cut from a bit of vinyl tubing to get a good fit. A cornie can also be used as a primary fermenter if you fit it with a large diameter blow-off. Details on how I do this are at http://chattanooga.net/~cdp/kegferm/kegferm.htm c.d. pritchard cdp at chattanooga.net http://chattanooga.net/~cdp/ Return to table of contents
Date: Sun, 22 Jan 2006 15:44:03 -0500 From: "steve.alexander" <-s at adelphia.net> Subject: yeasts attenuation/flocculation/storage Randy Ricchi and Fred Johnson bring up some good points ... One of the least well explained characterization parameter for yeast is "attenuation potential". The basic idea is that you drop some amount of the yeast into a closed fermenter of controlled media and observe the attenuation. There are SOME few brewing yeasts that will not handle significant sugars ... an Aussie paper a few years ago had an ale yeast that ignored sucrose for example. Despite this nearly all brewing yeasts have the genetic hardware needed to get "full" attenuation of wort. The difference between yeast is not the basic fermentation capability, but the expression of that potential. For various reasons the "less attenuative" yeasts stop growing and then typically flocculate before other yeasts. Flocculated yeast still ferment, but at a very low rate, and they do not rapidly attenuate wort. == Flocculation is a pretty straightforward topic. /Yeast given 'growth condition' do not flocculate. /If growth conditions do not obtain, then yeast with the genetic capability become POTENTIALLY flocculant. This causes dramatic changes to the cell surface. / Potentially flocculant yeast actually flocculate if certain environment conditions exist related to the flocculation genetics. [divalent ions like Ca++, low ethanol levels, pH ...]. Flocculation conditions almost always appear in normal beer. Corollary: / If growth conditions are restored to flocculated yeast, they de-flocculate. Note: There are non-flocculant wild yeast and these yeasts will also cease attenuating once growth conditions are removed. == Lack of growth conditions causes (potential) flocculation and additionally causes stalled attenuation. Don't confuse flocculation with a cause of incomplete attenuation. That's like blaming brown leaves for the cool weather of Autumn. An early flocculating yeast is also one with more stringent growth requirements. Despite this many studies have shown that carefully lab conditions can achieve ABV% in the mid-teens and even over 20% with common brewing yeasts. The reason that barleywines are difficult to ferment is primarily in the poor growth conditions NOT fundamentally the yeast. Of course choosing a yeast with less stringent growth requirements makes it that much easier to get full attenuation. It's been know for a long time that different yeasts have different oxygen requirements - some can ferment normal wort cycle after cycle with 8ppm of O2, while some varieties need 24+ppm. If you examine the yeasts it appears to me that the hi-O2-req yeasts are all ale yeasts and often low-attenuating top fermenters. Perhaps these yeast can't use both O2 atoms when making lipids or perhaps these have lower maximum lipid content. In any case lack of oxygen req lipids (sterols & UFAs) is a very common reason for lack of growth and probably the leading cause of incomplete attenuation. The other thing that's not clear to the average brewer - yeast have to pump ions in&out of their surface membranes across a very considerable osmotic pressure gradients. The osmotic pressure is related to the molar concentration and most of the molar concentration in wort comes from fermentable sugars (abt 2/3rd of extract is fermentable, but this is well over 2/3rds of the non-water molecules). The story gets MUCH worse as fermentation progresses. every glucose is converted to 2 ethanols, every maltose to 4 ethanols, and the maltotriose to 6 ethanol molecules. Fermentation progress cause a rapid and radical increase in osmotic pressure, and at the same time the cell membranes become dramatically weaker as the original sterol&UFA is spread out among 4 to 10 times more cells. The weaker membranes permit more ion leakage and so more work for the cells. Of course hi-grav brewing is the worst case scenario, The rule of thumb that you should pitch yeast in proportion to the OG is the right direction but doesn't go far enough. If you usually use X amount of yeast in a 5gal, 12P wort and you double the pitching rate for 5gal of 24P wort you still fall short of the mark. In the second case the strong 24P wort holds LESS O2 than the 12P stuff, and it's divided among twice as many cells. By the time the fermentation is finished the 24P wort will have twice the osmotic pressure as the 12P so the yeast will be under far more stress. I 'm not a hi-grav beer fan, but if you are then plan on pitching far more yeast and consider pitching well aerated starters several times throughout the fermentation. I'd also suggest that some of the less finicky yeasts like WY1028 would be a better choice than WY1084 for the hi-grav range. High CO2 levels also slows growth. Limited FAN, perhaps especially in high grav heavily pitched wort is a likely source of growth limitations. === It was odd to read FredJ's comments about storing stalled starter yeast under beer in fridge. After years of carrying far too many yeasts around on frozen plates I have honed in on the same method. I just pulled an ale yeast back (easily) after a year under beer in the fridge. I have a modest library under beer in whitelab type tubes. I would never suggest pitching these directly, but it seems to be adequate for culture storage. I wonder how well it would work with some of the more delicate yeasts. >Is there anything likely to be wrong with the yeast stored and >revived in this manner? Petite mutants? Selection of >subpopulation? Probably not petites assuming you do a build-up but we are selecting a subpopulation that can survive the selection & cold storage. That *might* correlate with things like more storage carbos or better membrane integrity. One might speculate that this might advantage early flocculation lower attenuation, but it's only speculation. -S Return to table of contents
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