HOMEBREW Digest #4751 Thu 31 March 2005


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	FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES
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Contents:
  Re: Old Grain (Don Trotter)
  Re: Enzyme confusion and step mashing (The Grant Family)
  Re: More on late diacetyl ("Fredrik")
  diacetyl and oxygen (leavitdg)
  New Orleans Beer Places (Bob Barrett)
  Re: Malted Oats and Grain Questions (Jeff Renner)
  Enzyme confusion and step mashing(correction 1+2/3) ("-S")
  Siphon Starter ("Peed, John")
  Round two - Enzymes and step mashing ("Michael Wright")
  ProMash Updates ("Janie Curry")

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---------------------------------------------------------------------- Date: Wed, 30 Mar 2005 22:45:12 -0600 From: Don Trotter <donniestyle at directlink.net> Subject: Re: Old Grain I would say, don't throw out the grain. I have used some 4 year old grain, and produced a very good beer with it. I just used the grain, with hops that were accumulating, and dry "Superior" lager yeast to make a California Common. Surprisingly, the beer turned out extremely good. I have to agree to the reply post from Gary Spykman, and the mash efficiency is lower. I usually see about a 80-90 percent mash efficiency, and with the old grain (kept in buckets in the garage), I saw only 73 percent. Happy brewing, Don Trotter Return to table of contents
Date: Thu, 31 Mar 2005 14:10:16 +1000 From: The Grant Family <grants at netspace.net.au> Subject: Re: Enzyme confusion and step mashing Mike asked: >if the beta rest is before the alpha rest, how is it that there is a >decent substrate for the beta-amylase to chomp on? You're right; it would make a lot of sense to break down starch with alpha-amylase first. The main reason that this isn't done is because the beta-amylase, which has a much shorter half-life than alpha-amylase in any case, is quickly denatured (destroyed) at temperatures considered optimal for alpha-amylase. In other words, a rest at 70C (158F) for 15min or so would denature almost all available beta-amylase and render the subsequent rest at 60C (140F) useless. The other point to note is that beta-amylase is much less active than alpha- in the first place (I heard that alpha- was 20 times more active - or was it 20 times more plentiful...), and that beta-'s half-life isn't even that long at its optimal temperatures. Both these facts suggest that you really need to use the beta- as soon as possible once you're saccrification temperature range. Beta-'s vulnerability is why is it best to finish the mash with a higher temperature rest - to make sure you finish off the starch conversion. On the other hand, one idea I've had for a while is, instead of doing multiple water additions, to do multiple grain additions. So, you could mash in with 80-90% of the grain for a 70C (158F) rest for 20-30min, then add the rest of the grain to bring the temperature down closer to 60C (140F) for increase maltose production from the "fresh" beta amylase you're adding. Anyone tried it? Cheers Stuart Grant, Hobart, Tasmania, Australia. Return to table of contents
Date: Thu, 31 Mar 2005 09:22:13 +0200 From: "Fredrik" <carlsbergerensis at hotmail.com> Subject: Re: More on late diacetyl This is interesting stuff. I have very limited experience with this, but I still try to find some logic in this as I eventually hope to model these things. To try and nail this done, here are some questions. 1) Infections excluded, I am not aware of other non-enzymatic pathways to diacetyl than oxidation of alpha-acetolacate. Does anyone else know of any likely non-enzymatic and non-yeast related pathways to diactyl in beer? If not(?) - then it seems fair to assume that these reported beers having diacteyl peaks during storage/handling/racking must have had higher than acceptable residuals levels of aceto-lactate? Where else would the instant diacetyl come from? Does anyone disagree? If not, the next logical question seem to be why there is residual aceto-lactate left in the beer? Since from what I currently know, yeast can not remove the aceto-lactate directly, so it seems the first problem is that the aceto-lactate was not fully converted to diacetyl even at racking? or? As I understand the diacetyl rest has two functions. step1) Speed the oxidation of aceto-lactate to diacetyl by increasing the temperature? step2) Speed the absorption and reduction of the diacetyl to acetoin and butandiol. Thus, I am tempted to make the conclusion here that if there is aceto-lactate before racking, but not noticable diacetyl. Either a) The diacetyl rest seem to have failed to even pass step1? b) The diacetyl rest might have been successful as such, but was made too early, and more acetolactate was produced after the rest for some reason (I suppose there are many possible reasons?) Suppose there were two diacetyl peaks, then it would clearly make no sense to perform any diacetyl rests before both peaks has passed? I am curious to hear details from Francisco. Receipe, yeast strain, pitching rate, yeast preparation/aeration and procedure, fermentation time/performance, temperature? Details and of the diacetyl rest? I think there may be a lot of potential gain from other peoples experiences, and lots of time to save. It seems there are alot of unprocessed data out here. Maybe not as clean and unbiased as pro-lab data but still data worth processing. Our world is biased in more than one way anyway so I try to not be blinded by these things. If anyone have more details on all this, it would be interesting to hear more. Anything that could make the logic more clear. /Fredrik Return to table of contents
Date: Thu, 31 Mar 2005 06:46:50 -0500 From: leavitdg at plattsburgh.edu Subject: diacetyl and oxygen Francisco; If you think that oxygen is being introduced by way of your pump-siphon, you may want to take a look at the Quoin (party pig) siphon. You would need both the siphon and the small hand pump. I find that it works well. ..Darrell [and thaks to Steve for the informative post on Beta and Alpha amylase] Return to table of contents
Date: Thu, 31 Mar 2005 09:44:57 -0500 From: Bob Barrett <bob.barrett at gmail.com> Subject: New Orleans Beer Places Going to New Orleans the last weekend in April for one afternoon/evening. What are two beer places where I have to go? They could be brewpubs or beer bars. Not that interested in the food they serve. Just the beer. - -- We Make the Beer We Drink!!! Bob Barrett Ann Arbor, MI Right down the road from the homebrewing universe!!!!!! I mean I'm REAL close!!!!!! Return to table of contents
Date: Thu, 31 Mar 2005 09:46:56 -0500 From: Jeff Renner <jeffrenner at comcast.net> Subject: Re: Malted Oats and Grain Questions Art McGregor <A.L.McGregor at verizon.net> writes from Northern Virginia >Do malted oats need to be mashed with other enzymatic malts, or are they >sufficiently converted during the malting process to allow me to just steep >the grains to get the fermentables out? They might actually have enough enzymes, but you might well have some other issues such as slow runoff. Here is a note I posted a while back http://www.hbd.org/hbd/archive/4489.html#4489-6 I wrote Fawcett Malting http://www.fawcett-maltsters.co.uk, the producer of malted oats that are available in the US, about this product, and got this reply from James Fawcett (parts 1-3 were on brown and amber malt): "3) Oat malt laboratory worts are normally slightly hazy rather than clear. Oats are not normally low in protein and are quite difficult to modify from a protein viewpoint, which could well explain this. Our current stock gives values of 11.8 % total protein with an index of modification of 27.8%. "4) As far as mash schedules are concerned we would suggest you ensure temperatures are between 63 degrees C and 68 degrees C during mashing in with a one hour minimum stand after mashing in a grist composed of 50% oat malt and 50% lager malt. "5) You should aim at a liquor/grist ratio of between 2.5:1 and 3:1. "6) Oat malt needs very close mill settings to achieve an acceptable grist. For normal malts our standard mill setting is 62 thou top and 58 thou bottom- for oat malt we drastically reduce these settings to 48 thou top and 42 thou bottom. Certainly a point to watch to produce an optimal grist for mashing." >On a separate note, the malted oats are more difficult to use than I had >thought, primarily due to the husk on the skinny elongates shape of the >grains which forces the mill spacing to be much smaller, and results in a >fair amount of husk material/flour. I have noticed that some suppliers are >now offering dehusked malted oats (of course after I had already bought a 55 >lb sack of the stuff!) I think that the husks, regardless of whether or not they are broken up more than usual, will still aid filtering. I don't think that they will make for the alleged husky flavors simply because they have been broken up. (See archives for past discussions on this if you can figure out how to do a narrow search). >Another question is on the storability of malted grains. How long will >malted barley or malted oats stay viable (enzymes, etc.) if stored in dry >plastic buckets? what about if stored in sealed vacuum barrier bags? I >have some malts/barley (Chocolate, Black Patent, Roasted) that are probably >5 - 8 years old. Just curious if I should toss them and buy some new stock, >or continue to use until they gone, which could be quite a while. I'll be >brewing batch # 259 in a few weeks :^) That is certainly pushing it. If they are kept cool and dry, grains can last several years. I guess taste and smell should be a good guide, along with mash performance in the case of base malts. It sounds to me like, after 11+ years and 259 batches, it's time for you to push yourself into all grain! That will use the grains much faster. Jeff - -- Jeff Renner in Ann Arbor, Michigan USA, JeffRenner at comcast.net "One never knows, do one?" Fats Waller, American Musician, 1904-1943 Return to table of contents
Date: Thu, 31 Mar 2005 11:06:04 -0500 From: "-S" <-s at adelphia.net> Subject: Enzyme confusion and step mashing(correction 1+2/3) Doh ! Sorry but there is a significant error in my backgrounder related to a miscalculation of amylopectin properties. >[======= starch background ======== = > Each >amylopectin molecule has one reducing end and many (20-ish type numbers) of >non-reducing ends. Miscalculation , it's more typically 60 or 70-ish non-reducing ends for typical size barley amylopectin. >[== enzyme background===] >In a bucketful of fully gelatinized grain starch, the BA enzymes *initially* >has a fairly "even balance" of amylose and amylopectin targets per unit >mass. That is each amylose molecule averages a few hundred glucose units >and has one non-reducing end for BA attack. Also each amylopectin molecule >averages several thousand glucose units and several tens of non-reducing >ends(NRE). In both cases there is something around one NRE for BA > hydrolysis per couple hundred glucose units. Wrong for the same reason. Amylopectin has between 30 and 50 glucose units per NRE while amylose initially has several hundred glucose units per NRE. So amylopectin (fully gelatinized) has roughly 5X the number of NREs for BA attack per unit mass as does amylose (and there is about 4X as much amylopectin as amylose). A good fraction (tho' under 50%) of amylopectin mass could theoretically be reduced to maltose by a BA-type enzymes alone *if* all the NREs were accessible to BA attack. To reiterate, the theory fails because the NRE sites are inaccessibly lost in the amylopectin jungle (the hairy molecular structure). AA does make amylopectin more accessible to BA by two mechanisms 1/ by making the "buried" NREs accessible and 2/ by creating new NREs at the hydrolysis point. Both are important mechanisms. -S Return to table of contents
Date: Thu, 31 Mar 2005 09:29:11 -0800 From: "Peed, John" <jpeed at elotouch.com> Subject: Siphon Starter Francisco suspects that his siphon starter is causing oxidation in his beer, but I doubt that. I've been using one for years and have never noticed any oxidation or diacetyl problems with my kegged beers - I only have problems with beer that has been transferred to bottles (by counter-pressure). Dennis Collins also uses one, and his beers show no problems with oxidation. I'm still trying to figure out how oxygen could possibly get into my CP-filled bottles. I bottle at high pressure, and quick-slam a cap on explosive foam ... you would think (I would certainly think) that there's no way oxygen could get into the bottle under those conditions. I've also tried a number of other CP bottling methods - slow fill, fast fill, cap on all manner of foam, cap on no foam, slow purge, fast purge, extra long purge, regular caps, oxygen-absorbing caps ... have I left anything out? Oh, here's a great tip that Dennis came up with: blow the residual beer out of the bottler before filling the next bottle, to avoid blasting beer into the bottle (which will be filled with air) when you purge. Dennis even built a bottler entirely of stainless steel components (which I have been using for at least a year) because we kept hearing that copper and copper-containing alloys can oxidize post-fermentation beer. I built a special fixture to facilitate high pressure/quick capping. We've put a lot of thought, work and experimentation into counter-pressure bottle filling. We're getting better results but we still have problems. I'm seriously wondering if this bottling problem is an external oxygen issue at all. As for Dylan's bottle dilemma, I would petition the competition director for an exemption - they may well give you one if you explain the situation. I do not think you can open your existing bottle, transfer to 12 oz bottles and cap, and expect good results - "highly carbonated" and "effervescent" will almost certainly do you in there if you try to transfer it (let alone what the transfer might do to the flavors). And by the way, what's with all these archaic bottle rules, anyway? Do swing-top bottles leak? If the object is anonymity, how anonymous is a green bottle going to be? Or one that's not 12 ounces? Or not a long neck? Raised letters on bottles are verboten, but blacked-out caps are OK? I'd think you could make a very identifiable mark on a cap, but how unique is a Sam Adams bottle, with its raised lettering? Anyone else ever wonder about the validity of the bottle rules? John Peed Oak Ridge, TN Return to table of contents
Date: Thu, 31 Mar 2005 12:10:34 -0800 (PST) From: "Michael Wright" <wrightmi at gmail.com> Subject: Round two - Enzymes and step mashing Thanks to all for your responses/clarification regarding enzymes, mash temps and mash duration. Though I am keenly interested in the nitty gritty details (I continue to read over the responses again and again), I am also looking to pull out the key points for the amateur home brewer with very basic equipment. So please allow me to reduce the responses into practical steps I might take in a brewing session. Please note: The following paragraphs read like statements when in reality they are more like questions/assumptions. If I want a dry pale ale, then I would like a highly fermentable wort-easier said than done. To make steps toward a highly fermentable beer, I am hearing that a one approach might be a fairly simple two step mash (I've just taken a stab at duration): 1) Mash-in at ~60C(140F) for 45 minutes - Thoretically this should fully gelatinze the starches, slow the rate of BA denaturization and increase the fermentability of the wort (hopefully resulting in a dryer beer). 2) Increase the mash temp to ~70C(158F) and rest for ~30 minutes - This will increase the dextrins in the beer, which will reduce the fermtability but should still maintain a fairly highly fermentable beer because of the fist step at a lower temp. Am I on track? I realize for most of you this is rediculously simplified, but I am hoping to take away (outside of a greater understanding of the chemical processes that occur in the mash) some practical steps I can use to brew a better beer (better than a single temp infusion mash). Cheers, Mike Return to table of contents
Date: Thu, 31 Mar 2005 23:03:18 +0000 From: "Janie Curry" <houndandcalico at hotmail.com> Subject: ProMash Updates Anyone have problems getting update files from ProMash? I purchased version 1.8A about 16 months ago and registered it via their website. I haven't been brewing for a while so I've hardly used the program. And of course our computer crashed in the mean time. We had to reboot the hard drive and I had to install the programs again. I submitted my email address to the ProMash site a few days ago to receive update files and got rejected....it didn't recognize my registration email address. Their website says that the merchant supplies a piece of paper with a registration number on it. I'm sure that's how I registered a year ago, but I can't find it now. I emailed MoreBeer and they said they do not have / provide such a registration paper available but were able to confirm my purchase via receipt. I forwarded that on via the tech support address on the ProMash website but have not received a reply one way or the other. Have there been updates? Todd in Fort Collins Return to table of contents
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