HOMEBREW Digest #4628 Thu 14 October 2004

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  Re: Kinetics and Thermodynamics ("Fredrik")
  Re: Electric Brewery ("Pete Calinski")
  vertical or horizontal ("Dave Burley")
  RE: March pumps ("Ben Rodman")
  PH adjustments ("Peed, John")
  Sugars are utilized sequentially. (ALAN K MEEKER)
  Stainless Steel Pump Fittings (Benjy Edwards)
  re. Electric Kettle and Re-pitching ("zuvaruvi")

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---------------------------------------------------------------------- Date: Thu, 14 Oct 2004 07:54:38 +0200 From: "Fredrik" <carlsbergerensis at hotmail.com> Subject: Re: Kinetics and Thermodynamics Thanks for your follow up comments Dave. We seem to always have hard to understand each other. I don't know if it's terminology or just me which could be. In any case I appreciate the feedback. > Think of yeast as a catalyst promoting a chemical reaction > ( which energetically is possible, but not kinetically rapid) > via their enzyme and transport mechanisms. The yeast > do not wait or make energy decisions or look for the > weakest "prey". I am definitely attempting modelling the most relevant enzymes, were called for. But the core is how their activity is *regulated* as they obviously aren't constants, I refuse to belive that. I doubt a llist of enzymes alone will help me regulate them which seem to be the issue here. I continute to prefer treating yeas as a living *organism* that responds and acts to any situation in a way that is favourable for it's survival and reproduction as trained throughout evolution. The enzymes are there of course, but I think the fact that there is a living organism here is the key to understand how the enzymes are *regulated*. By considering the yeast an organism that does things for a reason, I think it's easier to understand and may allow simplifications. Why would a simple organism keep eating if it wasn't for the benefit of survival or reproduction? If you turn the question around, why not? Possibly(??) because it takes more efforts to stay awake and starve than to sleep and starve and hope for better times. I am just trying to find some logic here, so may you biologists forgive me if I am abusing the subject. Yeast continues to be an organism in my mind, and not reduced to a set of enzymes. I suggest consider the energy state of the organism as a whole. Then perhaps it's easier to understand regulations? Are you suggesting you do not belive in this idea Dave? This was the thing I wanted input on but I am not sure if the message went out. > If you were to start with all the same concentrations of > carbohydrates and look at the fermentation as it proceeds > you will find some carbohydrates are disappearing more > quickly and the final result may be there are certain > carbohydrates left depending on many different conditons > of the fermentation as well as the yeasts' genetic makeup. I agree with this but the question I want answered is how the genetic makeup + conditions govern the exact dynamics. > Point is, all of these carbohydrate reactions are proceeding > at the same time>, <NOT serially>, as you suggest in your > comments. Some are just slower than others. I think you misunderstood me? I never suggested a *litteral serial uptake* as a *mechanism*. The mechanism can be thought of a parallell uptake if you prefer to think of it that way, but the problem is to understand why it's regulated the way it is. If one sugar depresses another one it will appear like a "kind of serial uptake", but the mechanism isn't litteraly strictly serial. And the I doubt depressions are a logic switch, there are bound to be a smooth transition on closeup. Perhaps you are refering to the RDF = RDFW + (1-MTD) *MTW formula I posted?? that was meant to serve as a *ballpark estimate*. The model will be far better and more complex and not a formula. Please don't mix that formula with the model and my last posts. If it's this formula we are discussing then, yes it's just an rough estimate that I figure is alot better than nothing. There may also be tiny residuals of all sugars even within my suggestions. Once the sugar get as far as into the glycolysis chain there can't be any difference between sugars. The difference as I understand should be the uptake into the cell + preparation into g-6-p/f-6-p? In the model I am condiering the rate from external sugars to g-6-p/f-6-p. This step is regulated individually for each sugar. Each sugar having it's own regulation function. This regulation will not only depend on the strains genetic information, it will also depend on alot of other things. This is done in parallell of course, but in reality if one sugar depresses another there may be serial like effects. Here is a limited simplfied mind map showing some of the carbon flow.(only some pathways included, don't take it too litteral! it's not complete, forget the notes along the arrows, that's just "notes") http://hem.bredband.net/frerad/beer/modelling/pictures/pathways.jpg It will cause more confusion that clarity but here is one picture showing *some* pathways I am considering. In short Each arrow is a reaction mechanism. Each arrow has it's own regulation function. At each arrow all variables are accounted for. Each arrow represents and change of energy, redox, carbon, nitrogen, yeast. There is supposed to be a similar nitrogen flow map. > Change your concept and model and it will more > closely fit reality. What concept? I think you jumped into conclusions or what do you suggest I change? I don't understand what your main suggestion is? Serial/parallel isn't an issue, I think that is toying with words. I never suggested a litteral serial uptake, though the effect of depression is that simples sugars are given priority to more comples ones. I think this effect is *major* and I can't delegate to a second order issue. It's a first priority issue to account for. /Fredrik Return to table of contents
Date: Thu, 14 Oct 2004 09:32:36 -0400 From: "Pete Calinski" <pjcalinski at adelphia.net> Subject: Re: Electric Brewery I have been using heatsticks for three or four years. http://hbd.org/pcalinsk/HeatStk3.htm As for buckets, I use the 7 gallon buckets from swimming pool bromine. http://hbd.org/pcalinsk/Faucet.htm But I am getting concerned that the sealant, DAP 8641 is no longer available. I can't find it in any stores and DAP hasn't responded to my email queries. Pete Calinski East Amherst NY Near Buffalo NY http://hbd.org/pcalinsk *********************************************************** *My goal: * Go through life and never drink the same beer twice. * (As long as it doesn't mean I have to skip a beer.) *********************************************************** Return to table of contents
Date: Thu, 14 Oct 2004 10:37:33 -0400 From: "Dave Burley" <Dave_Burley at charter.net> Subject: vertical or horizontal Brewsters: Martin Brugard makes a good point about how to mount a centrifugal pump with regards to the bearing position and such. Jay Spies says: - ----------- "Yikes! I know that many people here on the HBD, as well as B3 (sponsor of the HBD) use these pumps vertically mounted." - ----------- I suspect there may be some confusion about what is a horizontal and what is a vertical mounting. As I interpret his comments, the axis of the pump ( that is the shaft to which the blades are fixed) is to be mounted horizontally. This would make the blades rotate in the vertical plane. Is this correct Martin? Keep on Brewin' Dave Burley Return to table of contents
Date: Thu, 14 Oct 2004 09:35:53 -0600 From: "Ben Rodman" <brodman at carmelclc.com> Subject: RE: March pumps Hi all, The orientation of a pump issue is interesting! I'd like to protect my investment... I've used the pump in both configurations, but here's what I need to ask: when we discuss vertical vs. horizontal, do we mean the body of the pump or the flow (perpendicular to the body)? Ben Rodman in Lyons, CO Return to table of contents
Date: Thu, 14 Oct 2004 11:30:47 -0400 From: "Peed, John" <jpeed at elotouch.com> Subject: PH adjustments I have tried adjusting strike and sparge water PH by adding 88% lactic acid. The PH of my filtered tap water has been around 8.0 lately, so I added acid to bring it down to 7.0 for strike and 6.2 for sparge. What I have found is that the resulting beer has a sour edge to the flavor and a very off sensation that's hard to describe. Call it a slickness in the texture and an overly satiating aspect to the flavor and general perception. In short, the beers that I made with these PH adjustments were ruined. The very worst examples resulted from acidifying the mash with 88% lactic acid. I have since switched to gypsum for acidifying the mash, but I have stopped adding any acid to the water(s). Am I using the wrong acid? And what really is the point of fiddling with water PH? I get 80% efficiency and excellent flavor without acidifying my PH 8.0 water, so I see no point in doing so. Fix mentioned that improperly PH-balanced beers aren't as stable as properly balanced ones. Comments? John Peed Oak Ridge, TN Return to table of contents
Date: Thu, 14 Oct 2004 12:03:38 -0400 From: ALAN K MEEKER <ameeker at mail.jhmi.edu> Subject: Sugars are utilized sequentially. Dave Burley stated: "If you were to start with all the same concentrations of carbohydrates and look at the fermentation as it proceeds you will find some carbohydrates are disappearing more quickly and the final result may be there are certain carbohydrates left depending on many different conditons of the fermentation as well as the yeasts' genetic makeup. Point is, all of these carbohydrate reactions are proceeding at the <same time>, <NOT serially>, as you suggest in your comments. Some are just slower than others. As you commented, there are some secondary interactions due to the "interference" of certain sugars, but the point is all of these reactions are going on simultaneously" - ----------------------- Dave, this is simply incorrect. As you may recall, I spent a lot of time in the past trying to explain this to you through off-line e-mails. You still haven't gotten the core concept here, namely that you are dealing with a biological organism that is /responsive/ to its surroundings. The protein catalysts you are referring to are protein molecules that have to be manufactured by the yeast cell before they can be put into use. The key point is that the yeast cell does not continuously and simultaneously manufacture every kind of protein that is coded for in its genome. As was pointed out by myself and others, to do so would be incredibly wasteful! Rather, many enzymes are only manufactured when their substrates are present, which, of course, makes perfect sense. If you don't like the predator analogy then how about a thermostat analogy. The yeast cells are constantly sensing their environment and responding appropriately. Much of the molecular details of these regulatory systems have been worked out over the past several decades, especially those relating to the detection and response to specific nutrient molecules, particularly glucose. You need to stop looking at the yeast cell as simply a bag of enzymes and see that it for the dynamic and responsive system that it is. If glucose is present the yeast will use that first and will not process the other sugars. This is not simply a kinetic phenomenon due to differing rate constants for the different sugar uptake and utilization systems, it is because the components of the other systems /are not made/ until the glucose has been used up. At that point the cell is forced to switch over to the other, less efficient energy/carbon sources. Pretty simple concept really. -Alan Meeker Return to table of contents
Date: Thu, 14 Oct 2004 16:54:00 -0400 From: Benjy Edwards <rdbedwards at gmail.com> Subject: Stainless Steel Pump Fittings Has anyone found stainless steel fittings to attach to the input/output threads of a March pump? I have been using brass fittings from the hardware store, but would like to upgrade to stainless steel. All web searches have yielded nothing. Thanks very much for a great forum! Ben Edwards Boathouse Brewery www.boathousebrewery.com Return to table of contents
Date: Thu, 14 Oct 2004 17:07:29 -0700 From: "zuvaruvi" <zuvaruvi at cox.net> Subject: re. Electric Kettle and Re-pitching Richard, I've used an electric kettle for five years. I changed to a shiny new 220v element about six months ago and I'm not happy with it. Metallic brew taste for the first five batches and it boils like crazy; I mean REALLY BOILS LIKE CRAZY. And if I step it down to 120v the watt denity is too low; just simmers. I did a Belgian Dark Strong two days ago and at 1.085 started to smell nice caramel notes. At 1.088 and 75 minutes into the boil, stronger darker melanoiden type odors wafted my way. I thought, "that's ok, Belgian Dark, this is going to be a groovy brew." Went into the kitchen to weigh out the final Simcoe, Hersbrucker, and Fennel Seed additions, and went back into the garage to find smoke scented steam billowing from the kettle. At around 1.090-091, despite being immersed in eight gallons of wort, this thing was pumping out enough heat to burn sugar. So now I have a Smoked Belgian Very-Dark Strong (Dion, didn't you have a similar experience a few years ago with wonderfully surprising results?) and a 220v element that looks a little limp of late (speaking of posts from down-under, don't I remember a recent post from another pilot/brewer with a similar problem?) and intend to put a spigot and a bazooka screen where the heater element is. And to address another recent post, I laid this stuff down on the yeast cake from my previous batch, which was racked off the cake as the wort cooled, and the new brew blew the airlock off the top within an hour; seriously, a new record, one hour. I use yeast cakes three and four times and have never had a problem (other than showering the shower with gookey green stuff). So, long story short, save yourself some trouble, skip the heater element, and go straight to gas. My .02 cents worth (or .03 or .04). Good luck, Chad Stevens QUAFF San Diego Return to table of contents
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