HOMEBREW Digest #3065 Thu 24 June 1999

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  Yeast Cake Re-use, Lag Time ? (Randy Shreve)
  maltotetraose fermentation !! SG vs reducing end conc. ("Stephen Alexander")
  RIMS Controller (Jonathan Peakall)
  Converting Kegs (Eric Schoville)
  (0, 0, 0) Rennerian (Jeffry D Luck)
  re: Thanks to everyone for their responce ("David Kerr")
  False Bottom and scorching.... (Jim Cave)
  "proper" beer engines (Marc Sedam)
  lid on boil pot (PRS) - CPC" <PRS at NA2.US.ML.COM>
  RE: Thanks to everyone... (PRS) - CPC" <PRS at NA2.US.ML.COM>
  Stressless Mash Mixing? (Joy Hansen)
  Flocculation ... ("Stephen Alexander")
  typos (Tim Anderson)

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---------------------------------------------------------------------- Date: Wed, 23 Jun 1999 08:01:31 -0400 From: Randy Shreve <rashreve at interpath.com> Subject: Yeast Cake Re-use, Lag Time ? I just tried re-using the yeast cake from a finished batch of beer for the first time. I was somewhat surprised as to the relatively long lag time. There was no fermentation activity at all for the first 4-5 hours, and to me, that's a LONG lag time. By the next morning at pitch plus 12 hours, fermentation was vigorous (phew! - insert heavy sigh of relief....). For my normal very healthy starters, I usually see activity within 2-3 hours of pitch. Here are the stats: Wyeast 1098 (19 days old) from the secondary of a 1.084 batch of Old Took Barleywine, with a very thick yeast cake. The new addition was a 1.040 batch of Butterbur's Bitter. The batch was well aerated using my standard filtered aquarium pump with airstone method, which typically gives me very good results. I'm just trying to understand this. Was the lag due to (1) the yeast being in food deprivation dormancy, (2) sluggish due to the high alcohol content of the Barleywine, (3) shocked because of the gravity differential of the two batches, or (4) all the above? Thanks!! Randy in Salisbury, NC (Long time HBD lurker, and seldom poster) Middle Earth Brewing Company Peace and Long Life! Return to table of contents
Date: Wed, 23 Jun 1999 10:09:00 -0400 From: "Stephen Alexander" <steve-alexander at worldnet.att.net> Subject: maltotetraose fermentation !! SG vs reducing end conc. David writes ... >I think it looks OK, but please put in the comments >that the tests you ran are on beers which have >been primed Is this so Louis ? Were they all primed ? >I suggest you give us a chance to comment prior >to publication on submissions like this in the future. How unfortunate for some that there is a free flow of ideas. >Data I have seen suggests that ale >yeast can metabolize tri-saccahrides Obviously they do - this is well known. >and lager >yeast can also metabolize maltotetraose in the >so-called "secondary" fermentation. This will come as great news to whisky distillers which currently pays a premium price for a proprietary yeast (called "M" type) which is capable of *partially* fermenting maltotetraose. This will also come as news to Gerald Reed and all those guys at Cambridge Univ press, publisher of a great many books on food science, who make the opposite statement (see 'Yeast Technology', Cambridge Press, 1989). Seriously -What "data" have you seen to support this surprising statement about lager yeast fermenting maltotetraose. Please cite the source if you actually have one. >You may also wish to comment that 0.5% sugar >is on the order of magnitude of one or two SG units. For trisaccharides - the most prevalent sugar at/near EOF 0.5% Clinitest is 6 SG degrees, not "one or two". Steve Return to table of contents
Date: Wed, 23 Jun 1999 07:44:53 -0700 From: Jonathan Peakall <jpeakall at mcn.org> Subject: RIMS Controller Howdy, I am looking for a schematic to build a RIMS controller. Anyone out there have one? TIA, Jonathan Peakall ******************************************** "I don't feel we did wrong in taking this great country away from them. There were great numbers of people who needed new land, and the Indians were selfishly trying to keep it for themselves." -- John Wayne ******************************************** Return to table of contents
Date: Wed, 23 Jun 1999 09:45:00 -0500 From: Eric Schoville <eschovil at us.oracle.com> Subject: Converting Kegs Badger asks for more info on using a grinding wheel on his circular saw to cut the top out of a keg. I just so happen to have some pretty detailed info on converting kegs at my webpage at: http://home1.gte.net/rschovil/beer/ BTW, I used this method as well and it works great. Ron, I can't imagine using my Dremel for this task! How many cutoff wheels did you use? One $2.00 cutoff wheel for my circular saw converted three kegs! Eric Schoville Flower Mound, TX Return to table of contents
Date: 23 Jun 1999 08:15:30 -0700 From: Jeffry D Luck <Jeffry.D.Luck at aexp.com> Subject: (0, 0, 0) Rennerian Jeff Renner wrote: >(PS - I'm going to be doing field research the next two weeks on the >indigeneous fermented and/or distilled beverages of Ireland and the >facilities in which they are consumed. See you all later.) Oh oh. Ireland! Does this mean we all have to prepare for a coordinate shift?!? Better strap down your lose equipment and cushion your carboys. I've heard that this kind of cosmic upset can skunk any beer you're fermenting. Now we know who to blame. ;-) Jeff Luck Salt Lake City, UT USA Return to table of contents
Date: Wed, 23 Jun 1999 11:17:58 -0400 From: "David Kerr" <dkerr at semc.org> Subject: re: Thanks to everyone for their responce Ed Seymour wrote: >The recipe stated that 60 minutes would be all that was needed for starch conversion. I used >90 minutes ( the Redsoxs were playing, and Nomar was at the plate). He drives me crazy with all of that glove adjusting, but a 30 minute at bat? Looks like you found the culprits (boiling temp strike water, fast lauter). Mash-out refers to raising the temp of the mash from sacc. temp to somewhere around 170F once conversion is complete. A marginal benefit is reported by many due to a less viscous mash at higher temp, others claim it to be a waste of time. Please post tasting notes, etc. My money is on FG 1.018. Any guesses more educated than mine? Dave Kerr - Needham, MA Return to table of contents
Date: Wed, 23 Jun 1999 09:04:45 -0700 From: Jim Cave <cave at psc.org> Subject: False Bottom and scorching.... I would just like to counter Jack Schmidling's comments about a false bottom and scorching. I use a false bottom with a converted sankey keg and have never encountered an incidence of scorching. I use a 35,000 BTU natural gas Hotwater tank heater and can step ~45 litres of combined mash and grain at a rate of 1.5 degrees F per minute without difficulty or scorching by simple stirring. Please note, this is not a pitch for a false bottom. I've heard very good reports about Jack's Easy-masher and might have gone that route had I thought about it a bit more. However I am largely satisfied with the false bottom approach, perhaps regretting the amount of time it takes to recirculate (as compared with what I've heard about the Easy Masher). However, the volume of my false bottom is perhaps 3-4 litres (encompassing only the curve portion of the sankey keg). I still am able to achieve brilliant run-off. BTW, using another smaller sankey as a decoction vessel, I have also never had a scorching problem with decoction mashes, even decocting (total) thick mashes of over 35 lbs of grain for doppel bocks. Jim Cave Return to table of contents
Date: Wed, 23 Jun 1999 13:04:58 -0400 From: Marc Sedam <marc_sedam at unc.edu> Subject: "proper" beer engines Since the queue was short, I thought I'd add this little tidbit to the collective. I copied the information here, verbatim, from http://www.breworld.com/homebrew/real_ale.html, which is maintained (and presumably written) by Gillian Grafton. I especially liked the second to last sentence. The site also has great information on where to get all the trimmings for real ale. - ------- Beer Engine This is the correct term for the device commonly seen in British pubs which pumps beer from the cask to the bar. Also known as a handpump or beer pump. It can't be emphasized enough that you should use the correct beer engine for the style of beer. Beer engines have two styles of neck, the swan neck and standard neck. Swan necks do untold damage to beers with a flowery hoppy aroma knocking the aroma out of the beer. The second feature which affects the beer is the sparkler. Sparklers force the beer through many small orifices producing a tight frothy head on the beer. Northern style beers (eg Tetley) should be dispensed through beer engines with a swan neck using a sparkler and produce an excellent pint that way. Southern style beers (eg Fuller's London Pride) should NOT be dispensed via a swan neck and certainly not through a sparkler. The result of this is of course, that Southern beers are not served with a head. Southern beers served in the northern manner are lifeless travesties of beers, whilst served in the proper manner they are a revelation, a wholly different beer. So the moral is get the beer engine appropriate to the style of beer you have brewed. Cheers! Marc Sedam Proprietor, CEO, and Floor Mopper of the "Huisbrouwerij Zuytdam" Return to table of contents
Date: Wed, 23 Jun 1999 14:46:01 -0400 From: "Santerre, Peter (PRS) - CPC" <PRS at NA2.US.ML.COM> Subject: lid on boil pot Keith Menefy writes: "I use a big (200 litre) container for the boil. It is posible to put a lid on with just an inch pipe outlet for the steam. If I restrict this outlet a bit more would it increase the temperature at all, and by how much. Is the steam coming off the same temp as the water being boiled?" Mark Tumarkin writes: "Aside from the question of steam temps it is not a good idea to cover your boil pot with a lid. One of the reasons for boiling is to drive off chemicals that can cause taste problems, such as DMS. If you cover the boil these are not driven off, or they can condense on the lid and drip back into the wort. So covering the boil is not a good idea." I write: Did you miss the part about him having a one inch pipe venting the steam? I've heard that DMS is a pretty volatile (in Standard Lazymans Units) substance and that it doesn't take much boil time to get most of it out. It's true that some of it may condense and return to the boil (if that is how it would work) but with a 60 or 90 minute boil with a pipe vent it seems to me (this is more of a question than a statement) that it would be sufficient to get all the DMS out. So I guess my question now it, how long does it take to get DMS out of your wort? Time, boil rates, wort composition etc. Peter Santerre Head brewer - 24 Square Foot Brewery. San Francisco, CA Return to table of contents
Date: Wed, 23 Jun 1999 15:14:20 -0400 From: "Santerre, Peter (PRS) - CPC" <PRS at NA2.US.ML.COM> Subject: RE: Thanks to everyone... Edward Seymour wrote: "with some substitutions necessitated by the local home brew store stocking policy (they like to keep only a small stock, as they want to make sure that the customer receives the freshest ingredients)." I comment: If I just had a one dollar bill for every time I heard that excuse I would be rich. Alright, not rich, but I could have bought a case of Morretti by now I bet. Peter Santerre Head Brewer - 24 Square Foot Brewery. San Francisco, CA Return to table of contents
Date: Wed, 23 Jun 1999 19:45:01 -0400 From: joytbrew at halifax.com (Joy Hansen) Subject: Stressless Mash Mixing? Hi Jack and Mike, I'm not really with the thread; however, the stirring motor I use operates flawlessly and I can't say enough about it. It's from H&R, is a high torque geared motor and turns at 3 RPM. The cost is about $80 including shipping. I've tossed the catalog, so I can't provide the phone or mailing address. This setup is neither practical nor recommended for direct fired mash tuns with a false bottom. The home built system I'm using is based on the Zymurgy article by Rodney Morris with considerable modification. I tossed the exterior drive gear on the motor and replaced it with a 1/2 inch copper pipe the length of the exposed motor shaft and pressed it into a 1/2 inch black iron pipe. The black iron pipe is long enough to serve as a union for the motor and a stirring shaft made up of 1/2 inch copper pipe. With a little ingenuity, a cross pin (a quarter 20 bolt) at the top of the stirring shaft that fits into the 1/2 inch black iron which is slotted for the purpose. It's easily fitted to the top of the shaft, is stable, and would break the stirring shaft before it could be stopped from stirring. When I cut the top out of the 1/2 barrel keg, I left the handles. The handles serve as a receiver for the mount attached to the stirring motor. The motor assembly separates from the stirring shaft and lifts off for adding malt, etc. The shaft has a single stainless blade that is angled 45 degrees from vertical and runs 1/8 inch from the false bottom. Two 1/2 inch copper pipe arms protrude from the shaft at about 3 inch intervals to mix the mash and supply the returning liquor to the mash. When mixing, the grist rotates counter to the direction of the stirring arms. How? I pump the liquid through a bottom fitting up through the stirring shaft. The fitting in the center of the bottom serves as the bearing point for the shaft and keeps the false bottom centered. A union for 1/2 to 3/4 at the bottom of the shaft fits tightly enough to slip, yet supply forceful liquor through the shaft arms, and also holds the false bottom in place. The false bottom is secured via my innovation to prevent rotation. Each of the arms has several 3/16 inch holes drilled which face opposite the direction of operation (including the scrapper blade shaft). The end caps are also drilled and are attached with a copper pin to facilitate brush cleaning of the stirring shaft. The scrapper blade is secured with an end cap and copper wire so it also may be removed for cleaning. Although I prefer a dough in at about 1:1 and the shaft/blade will tolerate the stress, I often prefer to just use my arm/hand since the 95 degree dough in temperature isn't unpleasant. I'm also confident that the dough in is complete. A dough in at 1.5:1 or more using a single infusion wouldn't require any hand mixing at all. This is a RIMS like system; however, I prefer a mix of infusion and RIMS heat for mash schedules. The problems I've had with this arrangement are as follows: The collection of debris and starch BELOW the false bottom. A real sticky mess if it stays there. It could also resist saccrification and send starch into the brew kettle. Home built false bottoms have collapsed, so I use the PBS punched SS false bottom with out a problem. Another problem is of my own making because I overload the false bottom which will create a stuck mash without stirring. I choose to make brews of 80 and greater gravity that result in approximately 30 pounds of malt and a finished ferementer volume of 8 gallons. This stirring system should work with both HERMS and Steam heating, but not with direct fired equipment. I use a pseudo sparge and recirculate to my standard of clarity (previously posted). I haven't tried making 5 gallons of 45 gravity wort in this system. This might require 10 pounds of malt and operate without stuck mash or debris under the false bottom. I don't attempt to brew low gravity because the commercial brewers do an adequate job and I find that light Bud, Miller, Milwaukee Best, etc. satisfy my need for a light lawn mower brew! I save my heavy Strong Scot Ale, Strong Belgian Ale, and Barley Wine for special occasions and friends! I previously posted a description of my mash stirrer on the HBD and invited interested HBDers to request an image I've prepared for the purpose. I'm not computer literate enough to have a Webb site to visit! Anyone attempting construction of a similar mash tun should have a qualified welder install fittings. My fittings cost about $8 each and the tig welding cost $5 for each fitting. A competant welder may save lots of fittings and several kegs! Any number of acceptable methods for cutting out the keg top are frequent HBD postings. I'd be interested in critique from HBDers who purchased this motor and applied it as a mash mixer. Cheers, Joy"T"Brew Return to table of contents
Date: Wed, 23 Jun 1999 21:31:48 -0400 From: "Stephen Alexander" <steve-alexander at worldnet.att.net> Subject: Flocculation ... Dave Humes asks ... >Here's a few questions for the microbiologists. Not one - tho' I sometimes play one on the HBD. >I've been wondering >what happens when yeast flocculate. Why do they start sticking >together when the food supply is running out? Too bad the Siebel guys blew off my question re flocculation. Some details below. >I have a starter going >now for an ESB strain that is very flocculent. The flocs are quite >large. Virorous stirring/shaking breaks them up to some extent, but >I'm sure at the microscopic level, there's still lots of cells stuck >together. What happens when the flocced yeast are exposed to a fresh >food and O2 supply? Do they "defloc"? Do some cells remain bound to each other? If so, does this affect their subsequent ability to support fermentation? Early work, circa 1970-1980 showed that yeast migrate toward an anode in electrophoretic experiments (in finished beer). Tho the effect is very pH related. Yeast can be deflocculated by washing in distilled water, and the reflocculated by adding bi- or poly- valent metal ions, especially Calcium++. Despite this the idea that flocculation is directly related to surace charge has been abandoned. Aside from the pH and the poly-valent ions a long list of substances were found to impact flocculation. Fermentable sugars and particularly maltose prevents flocculation and will cause deflocculation. Ca++ is reportedly necessary for flocculation of some yeasts, and sodium ions may prevent/decrease flocculation. Exhaustion of nitrogen sources may cause flocculation as well. The working theories at that time were that flocculation was a genetic property, that it is caused by calcium bonds between molecules embedded in the surfaces of the cell walls, and that prevention of flocculation was related to cell metabolism, might be an energy consuming process that involved nitrogen compounds in the cell wall. Altho genetic studies in early 1950s by Gilliland and Thorne indicated that flocculation was a genetic property controlled by 1 gene or 3 pairs of polymeric genes (depending on the study) it was a dominant trait - it wasn't until the late 1970s that the genetic studies of flocculence were revived. In the late 1970s Lewis Johnston and Martin showed that the FLO1 gene contains 3 related flocculation alleles (originally designates FLO1, FLO2 and FLO4). FLO3 was a flocculation mutation gene in a mutation of a non-flocculent strain, and characteristic FLO5 (in addition to FLO1) was identified by Russell and Stewart in 1979 in a brewing strain. Additional genes for flocculation have been discovered in various lab strains since. In the 1980s is was becoming apparent that flocculation was not a single mechanism, but one or more of several. There are expressed changes in the cell surface that include a change in the ratio of the amount of protein vs mannan in the cell wall. That perhaps surface carboxyl groups bond, or that Ca++ ions bridge between surface phosphate groups in the cell wall. Among most recent papers I have on the subject date from 1995 and describes *FOR A PARTICULAR LAGER STRAIN* the formation of a cell surface layer, and bonds between a lectin-like surface protein and related protein receptors. For this yeast conditions of >30ppm of Ca, <25C temp, and pH of around 4.5 must be met for flocculation to occur. The surface layer developed immediately after cell division ceased, and is related to lytic enzymes. A 1997 JIB paper (v103, pp257) investigated flocculation properties of a large selection of top and bottom fermenting yeast. (37 ales/tops, and 8 lager/bottoms) They conclude that top & bottom yeast flocculate by different mechanisms. That lager strains floc in the stationary growth phase in the presence of sufficient Ca++ ions (0.1 to 1.0 mMol) with sufficiently low sugar concentrations, due to a lectin mediated mechanism (should sound familiar) in which the cell surface changes. And that top/ale yeasts floc in the stationary growth phase, regardless of Ca++ ions, but only in the presence of sufficiently high ethanol levels (5% to 10% at pH 4.0-4.4) - and that cell surface changes are not apparent. Strains are variably inhibited from floc'ing in the presence of mannose, galactose and sucrose. Generally lager strain were inhibited from flocing by mannose and sucrose, but not galactose. Some top strains were inhibitied by mannose, but never by sucrose of galactose !! In another paper by the same guys as above (Dengis & Rouxhet and also Nellisen) that appeared in Appl.&Environ Microb, Feb 1995, pp 718 - fewer yeast, perhaps a bit more detail on proposed mechanisms. Sadly I feel that I know a lot less than I need to about flocculation too. >Do highly flocculent strains require higher >pitching rates? Don't know - my guess is that it won't help much. Very flocculent strains reportedly leave more acetaldehyde and diacetyl behind. -S Return to table of contents
Date: Wed, 23 Jun 1999 19:17:56 -0700 (PDT) From: Tim Anderson <timator at yahoo.com> Subject: typos I am a firm believer that picking on someone's spelling is extremely bad form. But then I also rather enjoy being a hypocrite. In today's HBD there are two gems: 1. Jack, who is usually much more careful (and who I suspect of using a spell checker) finishes a strong and pointed post with, "This is not possible with the EM although scorching is possible, it is more forginging." Hoo boy! I can't see to type through the tears! Jack, I demand that you back that up with numbers! Exactly how forginging is it? Oh my! Sorry. 2. Just as I got my convulsions under control, I read Jeff's assertion that, "Corn is a pretty neutral flavored brain - subtle, shall we say." Wheee! Nothing subtle about that! If there's one thing I can't tolerate it's a strongly flavored brain! Sorry about wasting everybody's time, and my humblest apologies to Jack and Jeff. My brain just isn't very forginging tonight. tim (Who lives in Portland Oregon and now feels morally obligated to by an Easy Masher.) _________________________________________________________ Do You Yahoo!? Get your free at yahoo.com address at http://mail.yahoo.com Return to table of contents
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