HOMEBREW Digest #2863 Fri 30 October 1998

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		Digest Janitor: janitor@hbd.org
		Many thanks to the Observer & Eccentric Newspapers of 
		Livonia, Michigan for sponsoring the Homebrew Digest.
				URL: http://www.oeonline.com

  Yeast Culturing - Inoculation Loop Problem ("Jeff Hewit")
  pump clogging (Wheeler)
  Fermentors? (Ken Schroeder)
  No-weld Keg or Pot Fittings (Jeff Ehlinger)
  bottling beer in wine bottles (Jay Hammond)
  Yeast Questions-Sloshing in the Secondary Fermenter ("Michael O. Hanson")
  A Study of Fluid Flow Through A Grainbed (John Palmer)
  Re: Vectored flow ("Peter J. Calinski")
  sterile buffer storage (Dave Whitman)
  Barleywine Yeast / Stovetop All-Grain (Ken Schwartz)
  IBU Measurement ("A. J. deLange")
  Re: mounting a thermometer in a SS pot? ("Bonnell, Doug")
  Home malting/Kilning (TOM CLIFTON)
  RE: Campfire Porter (correcting for too much chocolate malt) ("Mercer, David")
  Too much foam from Corny Keg ("Richard Scott")
  storing malt (Alan Edwards)

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---------------------------------------------------------------------- Date: Wed, 28 Oct 1998 20:26:20 -0500 From: "Jeff Hewit" <jhewit at erols.com> Subject: Yeast Culturing - Inoculation Loop Problem I recently decided to move up one more step in my evolution as a brewer, and started culturing yeast from slants. My first experience went without any problems, and the beer turned out great. However, I did experience a minor disaster the second time. First, the wire on the inoculation loop snapped after some mild mishandling. It broke near the handle, and I managed to pull out the stub, and insert the remaining wire with the loop into the handle. I thought I was home free. However, when I heated the wire, it fell apart - just disintegrated. I don't recall doing anything different from the first time. I ended up using a paper clip to transfer the yeast from the slant to the starter. The jury's still out on this technique. I used a propane torch - the kind plumbers use to solder pipe. Was the heat from this torch simply too hot for the inoculation loop? Did the first use somehow make the wire brittle or otherwise degrade it? Are there any tricks in heating the wire that I need to know? Would an alcohol lamp, like those sold by the yeast culture suppliers, provide a more friendly flame? Or, if I just got an inferior inoculation loop, where can I get a good one? I will appreciate any comments, suggestions, etc. Brew On! Jeff Hewit Midlothian, Virginia Return to table of contents
Date: Wed, 28 Oct 1998 21:46:12 -0500 From: Wheeler <wheeler at netaxs.com> Subject: pump clogging Randy Pressley asked about the possibility of grain clogging his pump and there has been mention of using scrubbies and filters to keep grain from getting into the pump. I have been using a stainless steel screen under my false bottom ever since I had grain slip under my false bottom and clog the drain. This arrangement has kept grain and grain particles of any significant size from getting through to the pump. There hasn't been any problem with compacting of the grain bed, even when making oatmeal stouts. The screen under the false bottom is made of two 12 inch dia. SS screens taken from splatter guards. The drain goes through the center of the false bottom and pulls the liquid from inside the saucer shaped SS screen filter. The pictures and some description are at http://www.netaxs.com/~wheeler/parts.html#falser bottom . Paul Schick asks about scorching and although I don't heat the mash tun with a jet cooker I do use a gas burner and have had no problem with scorching. With this setup I am able to drain at any speed from a trickle to a full flow. I do batch sparges to save time and being able to do a sparge at full throttle makes it even faster. I have yet to find any significant differences between fast or slow rates of flow when draining wort from the mash tun. Saving time is more important to me than decreased efficiency or the cost of a little extra grain so I do quick batch sparges. Red Wheeler in Blue Bell, PA my gas fired RIMS website http://www.netaxs.com/~wheeler Return to table of contents
Date: Wed, 28 Oct 1998 21:48:04 -0800 From: Ken Schroeder <knj at concentric.net> Subject: Fermentors? Sorry if this has been recently asked (I'm about 3 month's behind on HBDs): Where can I find ss fermentors in the 20 - 25gal size? Korny keg type with multiple down tubes would be great. Please email off line to take less bandwidth: knj at concentric.net Thanks, Ken Schroeder Sequoia Brewing Return to table of contents
Date: Thu, 29 Oct 1998 08:28:16 -0600 From: Jeff Ehlinger <jeffe at davis-lynch.com> Subject: No-weld Keg or Pot Fittings Last week I couldn't even spell "engineer" and today I is one! Greetings from a longtime "lurker". I thought I'd throw my $.02 in on the equipment side of brewing. People always seem to be asking how to add thermometer or valve fittings to the side of the keg or brew pot without welding. This is the best method I've found, which I use on my two converted kegs. This fitting will leave a female pipe thread to the outside to make up various valves, thermometers etc. There are two pieces required to make this "bulkhead fitting", both of which are SS. The first is a female x male coupling (adapter). The second is affectionately known as a Stop-A-Leak Seal, which is a SS pipe nut with a teflon ring molded to one side. These parts can probably be obtained many places but I do a lot of "company shopping" at McMaster-Carr and I've listed part numbers and prices from there. The chart below will (hopefully) cover possible sizes to use: Part No. Part No. Size FemalexMale Cplg. Price Stop-A-Leak Price Req'd Hole 1/4"nptf 48805K36 6.83 5530K42 3.25 5/16" 3/8"nptf 48805K42 9.10 5530K43 3.72 11/16" 1/2"nptf 48805K48 13.76 5530K44 5.56 7/8" Procedure for Assembly 1. Drill the hole in the side of you pot (keg), not too close to the bottom as the nut requires some clearance, see nut sizes below. Note, drilling a 7/8" hole for a 1/2" npt fitting with a hand-drill is difficult at best and somewhat dangerous, get a friend with a drill press to help you. 2. File or sand the hole edges smooth. 3. Insert mxf adapter with the male end into the hole and the female end to the outside of the pot. 4. Make up the Stop-A-Leak Seal to the male end of the adapter with the teflon ring facing the pot side. Tighten with a socket if you have one, here are the sizes needed: 1/4"npt - 3/4", 3/8"npt - 7/8", 1/2"npt - 1-1/8", deep sockets are not required. If you don't have a socket to fit, use a crescent wrench, the nut doesn't have to be super tight. 5. You could reverse the direction of the fitting to have the male end sticking out, it still works. Fittings screwed onto the male end of the adapter will still seal even with the nut on, just use two or three rounds of teflon tape on the male end. 6. For small pots (<13"dia.) you may want to beat a flat spot before you drill the hole, so the nut (stop-a-leak) will seal better. I'm sure I've forgotten something so feel free to private email questions. I've checked the parts numbers but VERIFY what you're ordering from McMaster. Usual disclaimers apply regarding holes drilled in hands etc. Sorry for the long post, I now yield to the "Clinitesters", "FWHers" and "Altbeerlings". Jeff Ehlinger Houston, TX. Return to table of contents
Date: Thu, 29 Oct 1998 09:35:00 -0500 (EST) From: Jay Hammond <jhammond at bryant.edu> Subject: bottling beer in wine bottles I wonder if anyone has advise on bottling beer in wine bottles. I have a batch of Kreik style beer ready to bottle and wonder if simply filling and corking the bottles will be good enough. Do you think that the type of wire stopper used on champagne bottles is required to prevent the corks from blowing out due to fermentation from bottle conditioning. Any ideas on this type of bottling would be helpful. Return to table of contents
Date: Thu, 29 Oct 1998 08:34:48 -0800 From: "Michael O. Hanson" <mhanson at winternet.com> Subject: Yeast Questions-Sloshing in the Secondary Fermenter Hello Fellow Brewers, I am writing with some questions about liquid yeast. Homebrewers seem to prefer liquid yeast. This does not seem to be the case with home winemakers. As a brewer, I have used both dry and liquid yeast. Dry yeast seems to work well and is easier to work with. It may be that some kinds of liquid yeast are not available as dry yeast or don't have dry counterparts. Liquid yeast is more difficult to work with because a starter is required or at least strongly advisable to reduce lag times. Using a starter with dry yeast will also reduce lag times. There seem to have been some legitimate historical concerns with available dry yeast. What is the current state of affairs? I know several Microbiologists who inform me that dry yeast can be as free of contamination or less contaminated than liquid yeast because of the method of preservation. Dry yeast also seems to last longer than liquid yeast. Wyeast cultures have a shelf life of 30 days according to some authors. I've successfully used dry yeast that I know to be over a year old. What advantages are there in using liquid yeast? Have strains of dry yeast become available that match the characteristics of liquid yeast in terms of attenuation, flocculation, and flavor profiles? If not, why not? If such strains are available, where could I find information about them? I would appreciate any information you could give me on this subject. Private e-mail is fine. Recently, a question was raised about sloshing in a secondary fermenter to rouse the yeast. This could be done if the headspace is filled with CO2 and the rousing was gentle enough to prevent oxygen getting into the beer. There would seem to be an increased risk of oxidation if the beer is sloshed in a secondary fermenter. I would suggest that the brewer make sure the target gravity has not been reached before rousing the yeast. Dry yeast can ferment very rapidly. I have often seen primary fermentations using dry yeast reach target gravity in the time indicated. A possible alternative would be to form an airtight closure and then rouse the yeast. I'm not sure how to go about this since I don't know the specific design of the carboy ad airlock. An undrilled stopper might form a sufficiently tight closure. The airlock would need to be replaced after the yeast had been roused to allow CO2 to be vented off if fermentation restarted. Thanks in Advance, Mike Hanson Return to table of contents
Date: Thu, 29 Oct 1998 09:45:23 -0800 From: John Palmer <jjpalmer at gte.net> Subject: A Study of Fluid Flow Through A Grainbed A Study of Fluid Flow Through A Grainbed Using a Manifold-type Lautering System Note: To the best of my knowledge, the following represents original work and should be considered intellectual property. For several years now, the question of how well a manifold lautering system works has been nagging at me. In 1995, Paul Prozinski and I wrote an article for BT called, "Fluid Dynamics - A Simple Key to the Mastery of Efficient Lautering". It was based on fluid flow as discussed in basic civil engineering and concluded that more coverage area was better to discourage "coning" of the flow and "dead zones" out at the corners. It is available in Volume 6, No. 5 of Brewing Techniques (1995). It corroborated earlier (independent) discussions posted by Al Korzonas to the HBD. In the 1995 Special Issue of Zymurgy (Great Grains), Al Korzonas had an article in which he and Steve Hamburg did a huge mash and then lautered equal portions in different types of lauter tuns.. The systems were: rectangular cooler and manifold, round cooler and Phil's Phalse Bottom, Pico Brewing System with copper slotted screen, Easymasher(tm) and a mesh-bottomed bag in a spigoted bucket (Miller-type system). The first three were adjusted to take 7 gallons of runnings in 1 hour. The last (Miller) could not be made to run so fast. It took 2 hours, wide open. The biggest variation was in recirc-time to get a clear wort. The EasyMasher was the shortest, followed by the others, with the Pico last, probably due to the large amount (~ gallon) of underlet/foundation water, so it was not surprising. (This paragraph courtesy of Al K.) As I was reviewing the technical edits for the Lautering chapter of my (still) forthcoming book, I turned a critical eye on my discussion of flow and decided that I needed more solid information rather than logical arm-waving. So, I contacted Guy Gregory, a Hydrogeologist at Spokane, and we set about trying to model how fluid flow in a lauter tun worked. Guy and I initially used Darcy's Law which is from fluid flow/civil engineering/hydrogeology science. Darcy's Law as modified by Wesseling (1973) states that V = 4KH^2/L^2 and V = Q/A Where: V = drain discharge rate per unit surface area in cm/sec, K= hydraulic conductivity of the grain = 2.5 x 10-2 cm/sec, H= Desired level of saturated grain at the margin of the radius of influence above the bucket bottom, in cm. L= 2x the radius of influence of the drain, in cm. (the unknown). Q = Optimum discharge rate A = Area of the tun The specific discharge, V, is equal to Q/A. Several years ago, Dr. Narziss of Weihenstephan University, wrote a paper in which he asserted that the ideal initial lautering rate was.18 gallons per min-ft^2. Narziss had directed that this number N be multiplied by the area of the lauter tun to determine a volume rate for ideal lautering. If you convert that number into terms of cm and sec then N is approximately .0122 cm/s. Well, if we say: V = 4KHsq/Lsq and V = Q/A and Q = NA, then voila, A drops out and we have V = N So, we get N = 4KHsq/Lsq Or, rearranging to solve for the drain spacing L, you get L^2 = 4KH^2/N Inserting appropriate values, rounding off to significant digits, and converting the units to inches instead of centimeters gives: L^2 = 8 H^2 or R^2 = 2 L^2 where R is the effective radius of drain, and equals L/2. The behavior of flow depends on the depth of the liquid (H), not the depth of the media. In groundwater situations, the media is usually higher than the water level, whereas for lautering, the water level is always above the grainbed. Using this equation, our model showed that for all but the shallowest grainbeds, a single pipe running down the center of a picnic cooler should be more than adequate for efficient drainage. But! Drainage is not the be-all and end-all of lautering. The experiments did not support this model. The Experiments: Single Drain To observe how the fluid flowed through a grainbed, I used a clear plastic filing box of dimensions 9W x 12L x 10H to conduct experimental lauters in, varying different variables- Depth, Flow Rate, and Drain Spacing. I used ground up corncobs (burnishing media) for the majority of the tests. They are of fairly uniform size (.03 inch) and Guy checked their hydraulic conductivity and it came out close enough to a barley mash. The corncobs were great for creating a reproducible testbed that could be conducted at room temperature without needing to be mashed first. Redundant experiments using a real spent mash showed identical results. In all tests, the drain(s) consisted of half inch hard copper tubing cut with hacksaw slots, connected via a bulkhead fitting to vinyl hose and metered by a ball valve. A standard flow rate for the tests was 1 quart a minute, unless flow rate was the variable. All trials were performed using continuous sparging, maintaining a constant depth. Here is a top view of the manifold layouts: http://www.realbeer.com/jjpalmer/manifolds.jpg Initial tests were done by injecting food coloring directly into the mash near the walls and observing the flow paths to the drain. The tests showed a parabolic path to the drain, with faster flow of dye in regions directly above and immediately adjacent to the drain versus dye placed out near the walls several inches away. The results disagreed with our initial drainage model and it was difficult to glean much information from this method. It caused a re-examination of the test procedure. The next set of experiments involved dying the whole water layer above the grainbed, opening the drain, and watching how the dye flowed into the grainbed. These results were much more telling of the way that sparging actually worked. After all, during the sparge, we are attempting to move fluid through all regions of grainbed to the drain and thereby achieve the best extraction. These experiments showed that there was a big difference in the flow rate, and thus the volume of water, that moved through the bed to the drain from areas above and adjacent to the drain compared to regions far away at the corners. Here are a series of pictures showing how the dye moves through the grainbed toward a single drain: 1. This shows the dye above the grainbed prior to opening the drain (in back). http://www.realbeer.com/jjpalmer/L61.jpg 2. This shows flow toward a single drain after about 2 minutes of flow. Note the coning of the dye front. A view from the side better shows the lack of dye to the bottom corner. http://www.realbeer.com/jjpalmer/L11.jpg http://www.realbeer.com/jjpalmer/L12.jpg 3. After 10 minutes, the dye has reached to within a half inch of the floor, but if you look closely, you can see that the middle area above the drain is starting to rinse clean already. Further observation showed this more clearly, but I ran out of film. As the sparging progressed, the far corners remained green while the center was rinsed clean. Here are two pictures showing identical behavior in a spent mash with a fair amount of sugar left. (1.015). The temperature of the mash was about 120F during the test, but I was lautering with 90F water, so it was cooling further. http://www.realbeer.com/jjpalmer/M11.jpg http://www.realbeer.com/jjpalmer/M12.jpg Other trials where flow rate or fluid depth were varied showed no significant difference in behavior of the dye front. Flow rate was tested at 2.2 quarts per minute and 0.5 quart/minute. The dye front moved faster or slower, but was the same shape. Varying the depth of the water, ie. the head height, seemed to change the angle of the cone a bit, but it was hard to tell. Dual Drains and Spacing The next round of experiments used two pipes connected to the bulkhead fitting with a Tee. The spacing between the two pipes could be varied. Trials were conducted with spacings of L = 4 and L = 6 inches. These spacings were chosen because the spacing of 6 inches in the 12 inch wide box results in a distance of L/2 between the pipe and the wall, while L = 4 equates to a distance L to the wall. We have suggested L/2 spacing in the past to minimize the affect of preferential flow down the walls of the tun, bypassing the grainbed. (However, due to the actual width of the tubes in this set-up, the distance to the wall was actually 2.5 inch instead of 3 inches.) The two spacings provided a good difference in predicted behavior. These trials had the following results (black circles are used to indicate drain positions): 1. With the pipe spacing at L=6, the dye front after 2 minutes of flow looked like this: http://www.realbeer.com/jjpalmer/L62.jpg 2. After ten minutes of flow, the dye front had reached the bottom, and the corners were already being rinsed. As mentioned, the spacing of the pipes to the walls is actually less than L/2. The residual color in the back corner of the tun is due to the position of the drain pipe there. Due to the length of the Tee fitting and the elbow fitting, the slotted pipe sits about 2 inches off from the back wall, whereas in front, it comes to within a half inch of the wall. http://www.realbeer.com/jjpalmer/L63.jpg The next trial was with L = 4, and it looked like this: 1. Before Flow. (some green is left over from the previous trial) http://www.realbeer.com/jjpalmer/L41.jpg 2. After 2 minutes. http://www.realbeer.com/jjpalmer/L42.jpg 3. After 10 minutes. Note some lack of flow at the corners. http://www.realbeer.com/jjpalmer/L43.jpg Time For A New Model Obviously, this data did not support the R^2 = 2H^2 model, or vice versa. I started thinking about what this data meant; specifically how to account for the differences in flow rate between different regions. I realized that the difference in flow velocity for two distances from the drain pipe, r1 and r2, must differ as a function of r^2, rather than just r (linearly). I bounced this hypothesis off Guy, and he agreed that, at the same depth or Head, that v1/v2 = r1^2/r2^2. Eureka! So, the flow velocity potential at any point in the grainbed is a function of the Head, divided by the distance from the drain (squared). V~ H/r^2 This brought to mind Ohm^s Law, which states that the Potential (V) divided by the Resistance (R ) in this case the grainbed and all subsequent plumbing, equals the Current (I) which in this case can be considered as the final flow velocity. It became apparent to me that by plotting the potential for flow across the dimensions of the lauter tun, I could model how the flow reacted to the position of the drain. The equation looks like this V = 100H/(x^2+y^2) The scaler of 100 was used to make V greater than 1 in all cases. With this idea in hand, I generated an Excel spreadsheet such that the cells each represented a actual square inch and calculated V for that cell's position relative to the drain. The drain was located at the bottom of this "tun", in the middle. The numbers immediately gave an indication of the convergence of the flow I had observed in the trials. I shaded similar values to help indicate this, and the result is below. http://www.realbeer.com/jjpalmer/spreadsheet1.jpg Two drains at L=6 looked like this: http://www.realbeer.com/jjpalmer/spreadsheet2.jpg I made up several spreadsheets for single and double drains and sent them to Guy. He agreed with the model, saying it looked like I had succeeded in solving 2D Steady State Flow without resorting to Finite Difference Analysis techniques. He was able to verify it using 3D Flow Modeling software that they have for modeling watersheds. In addition, he was able to take the spreadsheet values and generate equipotential flow gradient lines. These equipotential graphs match the observed flow patterns almost exactly. The graphs are shown below with gray arrows to show how the flow is vectored perpendicular to the gradient lines to approach the drains. Single drain: http://www.realbeer.com/jjpalmer/singlevectored.jpg Dual drain: http://www.realbeer.com/jjpalmer/dualvectored.jpg Three drains: Three drains spaced at 2, 6 and 10 in a 12 inch wide tun work even better than two drains. This spreadsheet is not to scale, nor is it shaded but you can look at the numbers and get the idea. http://www.realbeer.com/jjpalmer/spreadsheet3.jpg The spreadsheets show that with the increase in drains, you flatten the equipotential lines across the tun. Increased depth helps because it means that a greater percentage of the grain is up in the lesser gradient levels where the equipotential lines are flatter. This model is most applicable to rectangular picnic coolers since they allow a uniform 2D slice. Custom Designing Your Manifolds What I hope to do soon is to be able to have a Java applet on my web page which will take the tun dimensions, depth and the drain locations and generate a graph of the equipotential curves. One of the programmers here at work is looking into it. Further Experimentation Needed As with any theory and model, there is always more work to be done. As noted above - this model only looks at flow from a Potential aspect. It assumes that the media (grainbed) is homogenous i.e., that the resistance to flow in all cases is the same. In a real mash, this is obviously not the case. Noonan shows in Brewing Lager Beers that a cross-section of the mash has different particle sizes from top to bottom. In fact, during the trial using a spent mash, I had almost a half inch of that annoying topdough on top of the grainbed. It really slowed down the initial flow, even though the shape of the dye front matched what was observed using corncobs. Wort, by virtue of being more dense than water, and more viscous, will tend to underperform predictions based on water (see the Bernoulli equation) but basically all things being equal (head, temperature, etc.), a thicker denser fluid (syrup) flows through a small pore more slowly than a thinner, lighter one (water). With this in mind, you can hypothesize that as the sparge progresses, the difference in flow rate between the area over the drain versus the areas away from the drain will actually increase due to the increasing difference in wort viscosity and density between the two regions, which should affect extraction. More data is needed in this area. I think that one aspect of lauter tuns that allows this model to work is that the greatest constraint to flow is at the valve where we meter the flow rate, not within the grainbed. This difference provides for any inhomogeneities in the grainbed to be insignificant compared to resistance downstream. It also allows for all segments of the manifold to draw equally from the bed. This brings up a question I have had: How does the flow out of a false bottom into the open area beneath the false bottom, react to the single outlet tube? In this case, the flow is going from the resistive flow of the grainbed, to the unrestricted flow of the underlet area, to the constrained flow of the outlet pipe. Based on my work to date, I think that the flow from underneath the false bottom to the outlet point is affected by the same r^2 (maybe even r^3) of the manifold model. Or, perhaps there is enough mixing of the wort under the false bottom that any differences in flow from far away portions of the false bottom is not significant. Anyone have a transparent false bottom set-up? Return to table of contents
Date: Thu, 29 Oct 1998 09:20:48 -0500 From: "Peter J. Calinski" <PCalinski at iname.com> Subject: Re: Vectored flow In HBD 2862 Dave Ludwig wrote: [ lots of great stuff about gradients etc.] Boy I hope this makes sense when I read it in the morning. Cheers! I say, It did to me. So I ask: Can I make a good, effective manifold as follows? Home Depot sells copper tubing in flat coils, i.e.. not like springs but flat, spiraled from the center out. Could I buy a 5 foot length of say 1/4 inch ID tubing, crimp or otherwise seal the end at the center of the coil and cut radial slits partially through the tube with a hacksaw in a spoke like fashion? By radial I mean lay the whole thing flat and cut across all the coils at the same time. Maybe space the slits so they are an inch or so apart at the outer rim. I believe this would give me about 4 turns so the spacing between coils would be 1.5 inches or so. (I haven't worked this out in detail, I am just looking at the concept now.) To use it, from what I have read here, it should be placed at the bottom of the mash tun with the slits facing down. What does the collective wisdom think? Is the concept good? Is the spacing good? Would a different ID tubing be preferable? What are the criteria I am trying to meet? Flow rate, etc. Would an identical assembly serve as a way to feed the sparge water into the tun? Thanks in advance Pete Calinski East Amherst NY Near Buffalo NY 0 Degrees 30.21 Min North, 4 Degrees 05.11 Min. East of Jeff Renner Return to table of contents
Date: Thu, 29 Oct 1998 09:57:22 -0500 From: Dave Whitman <dwhitman at rohmhaas.com> Subject: sterile buffer storage In HBD#2862, Jim Liddil asks questions and raises objections about my experiment on buffering the water used to store yeast. >What was the cell number and viabilty based on methylene blue at the time the >cells wer placed into the vials? And what was the exact volume of fluid in each >vial? The volume of liquid in the vials was 2 +/- 0.1 ml. Each vial got two loopfuls of yeast solids harvested off actively growing slants. While no attempt was made to rigorously control the cell count, I estimate that differences in added yeast solids were about +/- 20%. It's not obvious to me what the initial or final cell counts have to do with anything, unless dead cells magically disappear. What matters is which method of storage gives a higher percentage of viable cells after storage. While I don't know what viability was at T=0, it seems unlikely that it was <95% since the buffered samples were higher than that after 3 months storage. >You n value is small and you have no idea what the cell number in the vials was >to start with. Did you take repeated samples from each vial and repeat the >procedure? As mentioned in the original post, viability was estimated with at least two microscope slides prepared from each vial, with multiple regions counted on each slide. I continued to count fresh regions and slides until I had recorded 800-1200 cells for each vial. The number of semi-independent determinations for each strain/treatment were: 1968 DI water n=8 1968 buffer n=7 3068 DI water n=6 3068 buffer n=6 As shown by t-test, given the large size of the effect, the experiment is more than adequate to distinguish between the two treatments. While I wish I had enough vials to block determinate error in preparing the samples, I did the best I could with the yeast solids I had on hand 3 months ago. ANOVA across the yeast strains showed a significant treatment effect with n=4 totally independent samples. >800 cells may be a statistically small value for the actual number >of cells in the vial. While I followed the published procedure's guideline on number of cells to count, Jim's comment is a red herring. The number of cells you need to count is related to the inherant uncertainty of the measurement technique and how small of an effect you want to be able to detect. It has nothing to do with how many cells are in the vial. Jim goes on to take cheap shots at my statistical treatment and method of determining viability, after I took pains to point out both the value AND limitations of the experiment in the original post. I'm left with the impression that Jim has been criticized for lack of rigor in the past, and has been saving up some bile for the first opportunity he got to dump it on someone. Would I have received this criticism if I had posted "Hey, I put some salt into my yeast samples and I think they stored better"? Petty crap like this certainly makes me less interested in sharing results with the collective in the future. - -- Dave Whitman dwhitman at rohmhaas.com "Opinions expressed are those of the author, and not Rohm and Haas Company" Return to table of contents
Date: Thu, 29 Oct 1998 08:21:01 -0700 From: Ken Schwartz <kenbob at elp.rr.com> Subject: Barleywine Yeast / Stovetop All-Grain Adam Holmes asks about attenuative yeasts for barleywines. I (and others who have posted here) had good success with Danstar Nottingham dry yeast. In my case, I had made an amber ale using Nottingham for Christmas give-away, and racked the BW wort onto that yeast cake. However, pitching from the foil should work well too and you have the added advantage of being able to add a LOT of yeast (a good plan for high-gravity worts) by using two or three packages (which will still be cheaper than liquid yeast...). My BW went from 1.092 to 1.017 in about a week on its own. ===== Adam also mentioned that he is brewing all-grain on a "crappy stove" by straddling the seven gallons over two burners. For anyone interested in all-grain but lacking space or equipment (like large vessels and good burners!), consider no-sparge or batch-sparge brewing! You can produce a smaller volume of higher-gravity wort which you can top off in the fermenter as you may already be doing with extract batches. Sure, it'll cost you some efficiency, but so what -- it'll still be cheaper than extract and you'll have all the benefits of all-grain recipe formulation at your command. No-Sparge brewing is done by mashing an all-grain wort as usual, but after recirculation, simply drain the wort into the brew kettle and let'er rip. No sparging involved (thus the name). Batch-sparging adds one more step, that being adding another charge of hot water after the initial wort is drained, stir, allow to rest a few minutes, and drain again. Has the advantage of retrieving much of the wort left behind in no-sparge brewing. In the brewing literature, it's usually been recommended to formulate no-sparge recipes by inreasing the grain bill by 1/3. I've worked up a mathematical analysis of both no-sparge and batch-sparge brewing which shows that in order to gain consistency and predictability in the formulation, a few things must be taken into account, and you may end up with significantly more than 33% depending on those factors. Watch for this addition to my webpage soon. ***** Ken Schwartz El Paso, TX kenbob at elp.rr.com http://home.elp.rr.com/brewbeer Return to table of contents
Date: Thu, 29 Oct 1998 11:11:48 -0500 From: "A. J. deLange" <ajdel at mindspring.com> Subject: IBU Measurement In the discussion of IBUs let's remember that even a measured bitterness value does not tell the whole bitterness story. The ASBC has 4 methods for measuring bitterness (one of which is archived i.e. not currently used). Method A uses solvent extraction (method D is an automated version of Method A) and spectrophotometric absorbtion at a single wavelength. Method C uses solid phase extraction and HPLC to estimate iso-alpha acids. Method A is sensitive to certain preservatives used in commercial brewing and Method C to the age of the hops used in brewing the beer. The two methods give results which are "practically identical" (quoting from the ASBC procedure) when fresh hops are used and, presumably, none of the interfering preservatives are present. Quoting further, ".. the IAAs [iso alpha acids measured by Method C] of beer brewed with old or poorly stored hops and with certain special hop extracts, can be significantly lower than the BU [Bitterness Units measured by methods A and D] figure. Thus, for homebrewed beer with the possibility, make that probability, of old or improperly stored hops, it is clear that Method A is preferred (not that any of us could afford the HPLC anyway) and we need to know, when a testing service is used, whether Method A/D or Method C is used. The ASBC Subcommittee on Determination of Isohumulone in Beer has determined that Method A "expresses the bitterness of beer satisfactorily" and the EBC also found that their similar method "..best expresses the true bitter flavor of beer." I interpret these phrases to mean that neither ASBC Method A nor the EBC method does better than give an relative measure of bitterness for beers brewed the same way. My IPA and Old Dominion's Hop Pocket both measure 50 IBU's. The bitter qualities of these two beers are, to my way of thinking at least, entrirely different. Throw in a Pils nobly hopped to that same level and you are in a dimension of bitterness mutually orthogonal to the bitterness of the first two beers I mentioned. Asked to rank these in bitterness I'd say the Pils was much less bitter than the ales and I'm not sure how I'd place the ales relative to one another. Thus it seems to me that the value of IBU measurement, is in common with many of the ASBC and EBC prescribed measurements, of most value to large scale producers who use them to insure consistency of product. Don't forget that these establishments also do elaborate taste panel testing. Also, don't get the impression I don't value measured bitterness. It's fascinating to compare measured bitterness data on a pair of beers with one's taste impressions of those same beers. Return to table of contents
Date: Thu, 29 Oct 1998 09:22:23 -0700 From: "Bonnell, Doug" <DBonnell at BreeceHill.com> Subject: Re: mounting a thermometer in a SS pot? On Wed, 28 Oct 1998 Badger Roullett wrote: > Greetings, from that wacky medieval guy... > > ok, so this is a modern day question, but i do that to... > > I have seen posts/webpages from people who have thermoters mounted in the > wall of their pots. How can i do that, and without welding.... can i have > so i can remove my thermometer too? for using on other things.. > > badger Most everyone is using a bimetal thermometer with a 3 inch dial made by Trend or Ashcroft. They have a 1/2 inch male pipe thread ( MPT ) on the back. One source on the web is: http://www.mcmaster.com/. Search for bimetal thermometers, page 363 of their catalog has the less expensive ones. I've installed mine by drilling a hole in the pot wall just large enough to take the 1/2 inch MPT fitting of the thermometer. I use a 1/2 inch locknut for electrical conduit. These are very inexpensive ( <30 cents ) and are quite thin for a nut of this diameter. The nut goes on the MPT fitting first and is threaded back toward the dial of the thermometer as far as is will go. Next comes a fiber washer, helps to provide scratch protection between the nut and the pot wall, plus allows tensioning to reduce leakage from thermal expansion. Insert the thermometer into the hole from the outside of the pot. From the inside, place an O-ring ( 7/8 inch ID by 1/8 inch thick ) over the threads and "roll" it up to the inner pot wall. You now have several choices how to secure the thermometer on the inside. You will want to use a "food grade" metal, copper, brass or stainless steel. These metal parts consist of a washer to go between the O-ring and a metal nut to tighten the whole assembly. BTW, screw the nut on hand tight from the inside and then use pliers to tighten the nut outside of the pot. This prevents tearing the O-ring. I haven't found any washers with the proper inside diameter. Copper and brass washers are easy to enlarge, but stainless steel washers can also be enlarged. I drilled out a 5/8 inch ID stainless "fender" washer. I used a stainless "half coupling" as a nut since the coupling cost less than $3, while a "real" SS nut costs nearly $6. A really cheap nut can be had by cutting the hex shaped section off of a copper plumbing fitting, should be less than $1. Be aware that the Trend thermometers sometimes have the last 3 or 4 threads on the MPT as a slightly larger diameter. This "locks" the thermometer into a standard full or half coupling, but makes it impossible to get a lock nut all the way back towards the dial. I had one such thermometer, so I put it's probe into a drill press ( hand tight ) and filed the offending threads as the thermometer spun. This allowed me to get the nut all the way back. My Ashcroft thermometers didn't have this "feature". So much for hardware, now.... back to software! :-) Doug Bonnell Return to table of contents
Date: Thu, 29 Oct 1998 16:20:56 From: TOM CLIFTON <t_clifton at usa.net> Subject: Home malting/Kilning I made a batch of "home grown malt" some time ago, and had pretty good success using a food dehydrator to dry and "kiln" the malt. I cut fiberglass window screen into large circles so the malt wouldn't fall through the cracks. The malt was extremely pale as the temperature never seemed to get over 115 to 120 degrees. The only problem I had was that I couldn't come up with malting barley and used a high protein feed barley. The result was poor germination, and the resulting malt was full of unmalted barley and irregular modification of the grains that did sprout. Tom Clifton St. Louis, Mo ____________________________________________________________________ Get free e-mail and a permanent address at http://www.netaddress.com/?N=1 Return to table of contents
Date: Thu, 29 Oct 1998 08:53:06 -0800 From: "Mercer, David" <dmercer at path.org> Subject: RE: Campfire Porter (correcting for too much chocolate malt) James Spies asks about 'fixing' a porter brewed with the following grain bill: 5 lbs. Marris Otter Pale 5 lbs. Weyermann's Munich 1 lb. 90 lov. crystal ~14 oz. Chocolate malt ~3 oz. Black Patent malt My experience with chocolate malt is a little goes a long way - I almost never use more than 4 oz in a recipe, and even half that (i.e. 2 oz out of, say, 192 oz, or roughly 1% of the grain bill) will be noticeable. I think that's your culprit here, more than the black patent or crystal. I've also noticed that the burnt edge from the chocolate, which I like in small doses, mellows over time. After as short as 3-4 months it is pretty much gone. You've got a lot of chocolate there, but my advice is, give it time. If you bottle and store the beer carefully, by Spring it should have lost a lot of it's campfire edge. But it could take longer. I have some stout that I brewed three years ago where I WAY overdid the roasted barley (I'm embarrassed to say by how much.) It took a year for that stout to be drinkable. Now it tastes wonderful: complex, malty, mellow and a little sweet. (But it still looks like burnt motor oil when I pour it.) The moral is, time corrects a lot of problems like this if you're patient enough to let it. At least, it's come to my rescue more than once. Dave in Seattle Return to table of contents
Date: Thu, 29 Oct 1998 11:30:12 -0600 From: "Richard Scott" <rscott57 at flash.net> Subject: Too much foam from Corny Keg Chuck Cubbler wrote: >However, after consuming a little more than half of the keg, I begin to >experience very foamy pours.......Guy at the homebrew supply said to >turn up the pressure, that the CO2 is coming out of solution..... He >suggested that I turn up the pressure, so I did, from about 12psi to >about 18 psi. What I get is a faster pour, still mostly foam. >From the Texas school of trial & error, I too experimented with fixing this problem. My fix: first was to make certain that I had properly carbonated the beer after racking (refer to Zymurgy, Summer 1995). Second, as the keg continues to drain, I backed off the CO2 psi by a bit. Too much made the beer go flat. Again, trial & error gave me the 10 psi solution that I use today at one-half keg or less. Another impact for me was the time it took to drink the keg. Now I have an excuse to hold more parties & finish the kegs quickly. :-) I keep CO2 bottle & keg in the beer 'frig at all times, always hooked up and picnic tap ready to dispense. My guess is that the 40 degreeF keg beer can continue to gain carbonation if the CO2 pressure is high. Further, without backing off the CO2 pressure, very highly carbonated beer is being spewed out at a high pressure. No doubt that the right hops & other ingredients greatly impact the good head, but I was concerned with the mechanical aspects of good kegging. Richard Scott Return to table of contents
Date: Thu, 29 Oct 1998 10:09:54 -0800 (PST) From: Alan Edwards <ale at cisco.com> Subject: storing malt Hi gang, I've finally decided to buy a mill and would like to get some sacks of malt to go with it. ;-) What are the finer points of storing 50 pounds of malt? Can you just put it in a RubberMaid container and forget about it? Or do you need to worry about the humidity or temperature? What are the natural enemies of malt and how do you keep them out? Thanks! -Alan in Fremont, CA Return to table of contents
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