HOMEBREW Digest #3827 Tue 01 January 2002

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  Happy New Year! ("Pat Babcock")
  re: Yeast Reproduction Limit? ("Steve Alexander")
  Re: keg lube and leaks ("Gregor Zellmann")
  RE: Wort recirculation thru CFC ("Steve Alexander")
  Brix/SG (AJ)
  re: Something new (Bierschnapps) (Jeff)
  almond flavour ("M Millspaw")
  More Keg Lube ("Kirk Fleming")
  bottled porter carbonation (Demonick)
  Yeast Reproduction Limit ("Pannicke, Glen A.")
  Yeast Reproduction Limit? (Demonick)
  Rice Hulls (Cas Koralewski)
  Rose Hips Beer ("John Gubbins")

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---------------------------------------------------------------------- Date: Mon, 31 Dec 2001 12:51:00 -0500 From: "Pat Babcock" <pbabcock at hbd.org> Subject: Happy New Year! Season's Greetings, Beerlings! Take me to your Holiday Ale... We at the HBD wish all of you a happy, healthy, safe and prosperous New Year! Be safe, consume responsibly. Welcome to 2002! - -- - All the best! Pat Babcock in SE Michigan pbabcock at hbd.org Home Brew Digest Janitor janitor@hbd.org HBD Web Site http://hbd.org The Home Brew Page http://hbd.org/pbabcock "The monster's back, isn't it?" - Kim Babcock after I emerged from my yeast lab Saturday Return to table of contents
Date: Mon, 31 Dec 2001 03:58:47 -0500 From: "Steve Alexander" <steve-alexander at worldnet.att.net> Subject: re: Yeast Reproduction Limit? Dave King asks ... >What governs the max yeast population in a primary? A deficiency in a growth factor or presence of a growth inhibitor is the only practical limit. Yeast don't take a census and have no clue or care about their population in any brewery fermentation context and don't subscribe to "planned parenthood" either. >[...] But how do they >know it's time to stop multiplying and time to make HOOCH? This is a common misunderstanding. Yeast NEVER choose between reproducing and making ethanol. Ethanol and reproduction are closely related (just as for humans!). Yeast produce ethanol as a by-product of fermentation. Yeast ferment sugars into alcohol to get energy for reproduction and other metabolic needs. Well almost. The exception is that yeast can, under rare circumstances, derive energy from sugar without producing ethanol. It's called respiration, but it doesn't apply to normal brewing.. In brewing, yeast will ferment the vast majority of the fermentable sugar into ethanol as they reproduce. In fermentation yeast take a wort glucose molecule (or produce one from a maltose or maltotriose ...) and derive energy by degrading this to CO2 and ethanol. Reproducing yeast have huge energy requirements as they build proteins and lipids for the new cells, so growing yeast convert lots of sugar to ethanol to get energy. We've all seen a stuck fermentation where a once active fermentation slows to a crawl. This happens when the yeast are unable to reproduce because some critical "growth factor" is lacking. Non-reproducing yeast cells don't die but require very little energy, so the fermentation rate drops drastically when a growth factor is lacking. It's bad for the beer if this happens before the fermentables are used up. What are the critical growth factors that can stop an active fermentation ? Oxygen, amino acids (FAN) and fermentable sugars top the list. One of the most likely growth limits for brewing yeast is oxygen. In brewery fermentations yeast take a big gulp of oxygen early in the fermentation and then can reproduce 8 to 16 fold without any more oxygen. If you pitch enough yeast that's the all the reproduction needed for a complete fermentation. Yeast use the oxygen to make sterols and unsaturated fatty acids for healthy cell membranes. If you underaerate or underpitch then the yeast become sterol/UFA deficient before the wort sugars are all fermented. They stop reproducing and a stuck fermentation results. The sterol deficient cells may also autolyze or produce more esters. FAN or free amino acids are the building blocks for all proteins and modern pale malts usually produce wort with enough FAN to allow the yeast to reproduce through the entire fermentation. Conventional recipes with large amounts of pale malt seldom are FAN deficient. OTOH if you make a beer with a lot of adjunct fermentables or use recipes with a lot of raw grain, then you are in danger of stalling the fermentation before all the sugars are fermented out. Crystal and roast and some specialty malts typically do not contribute much FAN to the wort. When wort is FAN deficient the yeast may be able, to a limited extent, to substitute other nitrogen sources for the missing amino acids, but this can result in slow and odd fermentations producing fusels. Fermentable sugars are an obvious limit to yeast growth. When the fermentable sugar runs out the yeast lose their primary energy source and reproduction stops abruptly. This is exactly what brewers want - the yeast ferments forcefully, growing without limitation right up to the point where the fermentable sugars run out and the beer is completely attenuated. This is not the best situation for the yeast left behind, but that's another story. There are a lot (dozens) of minor growth factors like biotin, pantothenic acid, zinc, copper, iron, calcium but these are rarely so deficient as to cause brewing problems (perhaps zinc). >The reason for the request was that I racked an IPA off the primary and >dumped a fresh wort directly into that primary. [...] > I thought about not oxygenating, since I >probably had plenty of the critters but I know the extra oxygen will get >scrubbed out, so it won't hurt anything. You should always aerate the new wort. If you hadn't you might have had a stuck or slow fermentation when your yeast ran out of sterols & UFAs. Yes you may have 3 times the normal amount of yeast, but if they are only fermenting at 1/10th the normal rate you still have a problem. -S Return to table of contents
Date: Mon, 31 Dec 2001 10:46:58 +0100 From: "Gregor Zellmann" <gregor at blinx.de> Subject: Re: keg lube and leaks Kirk Fleming wrote: > Once again, I'm embarassed to give > English units, but I really don't have easy access this minute to conversion > tables and I'm too lazy to do the math. No problem Kirk, I'm used to converting American units into metric, since I started homebrewing and reading HBD, r.c.b. etc. :-) Thanks to you and the other guys for answering my questions. I will get some silicone gel at the scuba shop. I checked all my 4 cornies (actually old Coca Cola pinlock kegs) on leaks with dishsoap and water and found that it is just one o-ring. As I needed this cornie for beer a couple of days ago, I used two o-rings on this peculiar lid and it seems to hold pressure this way. Cheers and Guten Rutsch Gregor Zellmann Berlin, Germany [4247.6, 43.4] Apparent Rennerian Return to table of contents
Date: Mon, 31 Dec 2001 05:03:14 -0500 From: "Steve Alexander" <steve-alexander at worldnet.att.net> Subject: RE: Wort recirculation thru CFC Steve Lane asks ... >Is anyone flushing the boiling wort through the CFC and returning it to the >boiler with a pump? I've been doing this since I first got a pump several years ago. It's a very nice method of cooling the wort, but you are also (wastefully) cooling the heavy hot SS boiler. I also sometimes hook up my old immersion chiller in-line like Steve Jones does and trickle the outflow cross the hot boiler exterior. My objective is to quickly cool the wort so I needn't be concerned with DMSO, and also to cool it enough that I can get very close to tap water temps out of the CFC. I haven't tried pitching & aerating in the cooled boiler but have nothing against the method. My only gripe is that the break particles are shaken, rattled and rolled. The only way to leave the break behind is to cool, wait and rack w/ a racking cane. A pump won't do it. Another suggestion is to recirc iodophor solution thru the pump, CFC and tubing for 20' prior to recirc'ing hot wort. Hot wort is not a sufficient sanitizer. This step was critical to getting a clean (no infection in unpitched wort after 72hr) wort test from my system. I don't understand when Steve Jones writes ... >I pitched the yeast and continued >to chill down to 65F. Then I diverted the wort to the >fermenters. I must comment that this worked out very >well, as I was able to run the valves wide open, >and the wort was crystal clear. Crystal clear pitched wort ?!!? Yeast will cloud wort immediately and significantly. The wort can't be clear of cold break particulate either. Perhaps there's no great harm in pitching and beginning the fermentation on some break, but the stuff ain't clear by a long shot. -S btw - I just heard from the long lost Dave Burley. Dave has been battling some very serious side effects from his arthritis meds, but is on the mend. Return to table of contents
Date: Mon, 31 Dec 2001 13:27:03 +0000 From: AJ <ajdel at mindspring.com> Subject: Brix/SG For Richard Perry: There are dozzens of interconversions between Brix (Plato) and specific gravity. A pair that receives little attention from the home brewing community but which is certainly accurate enough for all but the most demanding applications are the Lincoln Equations: P = (463 -205S)(S-1) and S = 1 + P/(258.6 - 0.8796P) where P is the weight of sugar per 100 grams of wort (i.e. the Plato degrees which closely approximate Brix degrees) and S is the specific gravity. A. J. Return to table of contents
Date: Mon, 31 Dec 2001 06:38:16 -0800 (PST) From: Jeff <duckinchicago at yahoo.com> Subject: re: Something new (Bierschnapps) In regards to breweries making other "distilled" products..... >>>Anchor Steam has gotten on the distilled spirits kick in a good way and sells a very interesting gin called "Junipero" and a very-expensive Whiskey called (I believe) "Old Portero". Haven't tried either, but have heard many good things about them. Although I have to say, for the price of the Portrero ($88), you could buy an amazing single malt scotch or small batch bourbon (or two very nice ones!) Anyone tried these? (I know this is a beer forum, but I figure Fritz is still 99% a beer guy.) Return to table of contents
Date: Mon, 31 Dec 2001 09:34:23 -0600 From: "M Millspaw" <mmillspaw at ameritech.net> Subject: almond flavour >Date: Tue, 25 Dec 2001 05:45:39 -0800 >From: "Schrempp, Michael" <michael.schrempp at intel.com> >Subject: Bitter almond flavor >Just put a Pilsner in bottles. At racking and bottling, it shows a slight >almond flavor. Not too bitter, just almond. Is this an off flavor, or a >desired flavor? The grain bill was 2 row weyermans, flaked barley, and >crystal. I did a triple decoction (9 hours from lighting the stove to >fermenter). I had this happen once also, the beer was a CAP type with a fair percentage of flaked barley. I used a Danish lager yeast slurry [1/2 gallon] that I had gotten from my neighbor. I should mention that he had already fermented a beer with this same yeast and it did not have the almond taste, the beer style and grain bill was quite different than my CAP. At the time I attributed the problem to the 2 gen. yeast (and slowly used up the beer by boiling ribs in it). But after seeing the mention of the flaked barley in the above post, I wonder could that be a component of this off flavour? My mash was a step infusion starting at 122 F. Micah Millspaw - brewer at large Return to table of contents
Date: Mon, 31 Dec 2001 08:50:44 -0800 From: "Kirk Fleming" <kirkfleming at earthlink.net> Subject: More Keg Lube In 3826 "John Zeller" <jwz_sd at hotmail.com> suggested finding the source of the leak rather than relying on Keg Lube to fix it. That's a good point--Keg Lube (or any lubricant or sealant) isn't probably a leak 'solution'. Its main utility for Corny kegs IMO is to lubricate ball valve O-rings to prevent damaging them when placing and removing the connectors. I've found that dry connectors against dry O-rings will often tear the O-rings. Kirk Fleming FRSL, FRSE Return to table of contents
Date: Mon, 31 Dec 2001 07:56:08 -0800 From: Demonick <demonick at zgi.com> Subject: bottled porter carbonation From: SLHMJL at aol.com >I used Primetabs at an English Ale rate. >I put 3 tabs in a 16oz bottle, and 6 in a litre. That's a very low carbonation rate. 3 PrimeTabs in a 12 ounce bottle is about right for an English Ale that has been properly roused to degas the green beer. Chill the bottles as cold as possible without freezing, uncap, drop in 2 more PrimeTabs per 16 ounce bottle and 4 more per liter bottle, recap QUICKLY. You might drop in one more per bottle for the decapping gas loss. The tablets may induce foaming, though getting the beer very cold will help alleviate the foaming. Let warm to room temp. There should be enough yeast left to do the trick in a couple of weeks. Domenick Venezia Venezia & Company, LLC Maker of PrimeTab (206) 782-1152 phone (206) 782-6766 fax Seattle, WA demonick at zgi dot com http://www.primetab.com Return to table of contents
Date: Mon, 31 Dec 2001 10:58:12 -0500 From: "Pannicke, Glen A." <glen_pannicke at merck.com> Subject: Yeast Reproduction Limit Dave King asked about yeast reproduction limits: >The reason for the request was that I racked an IPA off the primary and >dumped a fresh wort directly into that primary. Knowing that the 1st batch >fermented vigorously, and it had only been in the primary for 6 days, still >going strong, I figured the yeast were in great shape, but I still used my >normal spray device from the cooled brew pot to the primary, which >oxygenates the wort very well. I thought about not oxygenating, since I >probably had plenty of the critters but I know the extra oxygen will get >scrubbed out, so it won't hurt anything. Dave, it's a good thing that you aerated your new wort before dropping it onto the old yeast cake. Part of the flavor of beer is from the by-products produced during the yeast growth phase. Yeast require lipids for growth and can manufacture them from the oxygen in your wort. They can also get some lipids from trub, but let's only consider bright, trub-free beer here. During your first fermentation the yeast have reproduced a number of times, used up all of the oxygen and lipid manufacture has ceased. 14 hours of growth is the most often cited limit. After lipid production ceases, the yeast must then share the available lipid stores with their daughter cells to continue reproducing. This results in a logarithmic decrease in the cell's lipid content and eventually reproduction ceases altogether. In previous issues of the HBD, Dr. Clayton Cone has put this lower limit somewhere below 0.75% (with about 5% being the normal starting point for active dry yeast). Do the math here. 5% down to about 0.75% = approx 3 generations. If you did not aerate your second wort, you would have dropped it onto already "tired" yeast cells with little ability to grow and a lower alcohol tolerance. The lipids present in the cell wall also contribute to higher alcohol tolerance. Ergo, stuck fermentation. By aerating your wort, you've provided a nice little kick in the pants (do yeast wear pants?) to get things moving again. Fresh oxygen, more lipids, restored alcohol tolerance and continued healthy growth... Now if you you're thinking of bubbling pure O2 or air through your wort during the entire fermentation - don't. It's a good way to grow yeast, but a horrible way to make beer. It will turn out acidic and nasty-tasting. Try it. Make a starter and continuously aerate it with a bubble stone and an aquarium pump. Then decant the beer and chug it. Curiosity will kill me yet! A few shots of pure O2 at pitching, bubbling air into your wort for the first few hours or adding freshly aerated wort to your fermenting beer (around that magical 14th hour) should work fine. I've tried this on a few batches with no adverse results. But I also don't know if I gained any benefits either. You may also see references to "dropping" your beer ala Dr. Pivo. I understand this to be racking to a second container with slight aeration sometime around the "magical hour". He claims good results with this method. My advice: not worth the time UNLESS you're doing a high gravity beer (over 1.090 SG). The yeast will need all the help they can get! Carpe cerevisiae! Glen A. Pannicke glen at pannicke.net http://www.pannicke.net 75CE 0DED 59E1 55AB 830F 214D 17D7 192D 8384 00DD "I have made this letter longer than usual, because I lack the time to make it short." - Blaise Pascal Return to table of contents
Date: Mon, 31 Dec 2001 08:43:12 -0800 From: Demonick <demonick at zgi.com> Subject: Yeast Reproduction Limit? From: "Dave and Joan King" <dking3 at stny.rr.com> >What governs the max yeast population in a primary? I know the more >healthy, the better the nutrients, the higher the population. They need >oxygen during that stage, so good aeration is important. But how do they >know it's time to stop multiplying and time to make HOOCH? The assumption underlying the last sentence is a myth. Yeast will make alcohol while multiplying. Yeast will multiply under anaerobic conditions. In wort, even highly aerated wort, respiration (that is metabolism without making alcohol) is inhibited by the high sugar content of the wort. This effect is called the crabtree effect. It is well known and well characterized. Somehow the homebrewing myth got started and will not die. During brewing yeast never respire unless you reaerate after fermentation has slowed or stopped. Aeration at this time will induce the yeast to consume and oxidize the alcohol produced during the previous fermentation. This leads to horrible, off-flavors. I know - I've experimented with it :-) There are a few things that common limit the production of yeast in the primary under anaerobic conditions. When I say anaerobic I mean during fermentation, even though the wort has been aerated, the yeast are NOT respiring. They are utilizing anaerobic metabolism. The oxygen is being used for biosynthesis, mostly for fatty acids and sterols. The primary sterol is ergosterol and it is used to stabilize the cell membrane. Ergosterol can ONLY be synthesized in the presence of oxygen. Once the oxygen is consumed (within a few hours) the existing ergosterol is distributed among more and more cells until its levels fall below that needed for cell membrane integrity. At this point the cells go to sleep. How is the ergosterol "distributed"? As a cell grows the ergosterol distributes itself evenly across the cell's membrane. When the cell divides, let's say into equal daughter cells, each cell inherits half the ergosterol of the parent cell. When the daughters grow and divide the granddaughter cells inherit half of the half of the ergosterol. If enough of everything else is available, this ergosterol "dilution" will limit growth. If you are interested in aerated yeast starters, check out the webpage listed below. Yeast also needs to produce proteins to grow and stay alive. Since proteins are long polymers of amino acids, protein synthesis requires free amino acids (FAN) be available in the wort. High temp mashes and some malt extracts are low in FAN. This can limit the yeast production in the primary. Other than running out of sugar, these are probably the most common "limits to growth" (what ever happened to Paul Erhlich and the Council of Rome?) encountered by homebrewers. There may be some mineral deficiencies that can limit yeast grwoth, and these are better addressed by others. Cheers! Domenick Venezia Venezia & Company, LLC Maker of PrimeTab (206) 782-1152 phone (206) 782-6766 fax Seattle, WA demonick at zgi dot com http://www.primetab.com Return to table of contents
Date: Mon, 31 Dec 2001 16:22:43 -0500 From: Cas Koralewski <caskor at buckeye-express.com> Subject: Rice Hulls I am planning a Weizenbock and am going to use rice hulls to aid in the sparge. I'll do a protein rest at 130 F then saccharfication at 152 F. I also plan to do a decoction to bring the mash to a mash-out of 168 - 170 F. My questions: Will I experience any astringency from the rice hulls if I include them in the decoction? When should I add the hulls? Thanks, Cas Return to table of contents
Date: Mon, 31 Dec 2001 20:53:44 -0700 From: "John Gubbins" <n0vse at idcomm.com> Subject: Rose Hips Beer Howdy folks, Several months ago I asked about how to make Rose Hips Beer. I got a lot of response and chose my method. The stuff turned out to be excellent. It took a while to ferment and longer to bottle condition but it was ready by Thanksgiving. The folks at Thanksgiving dinner drank a case of it and most of the rest was consumed at Christmas. Normally I'm an all grain brewer, but this one is a partial mash. Here is the recipe: I picked the rose hips in September in the Colorado mountains by Bowen creek. They were nice and red and the freeze occurred a couple weeks before. They don't taste like much a bit sour perhaps, but there is a flavor in there. I sat around every night for a week before brewing with a grapefruit knife and dug the seeds out of them. One at a time. The Recipe: Blue Meanie Rose Hip Ale Brewed September 21, 2001 7 lb MF pale LME Couldn't get dried 2 lb Gambinus pale malt half lb wheat malt 8 oz lt german xtal 4 oz light munich 2 oz 6.7AA Kent Golding boil half oz HG Cascade boil HG is Home Grown 1 cup cleaned Rose Hips 15 min half oz HG cascade 10 min White Labs Dry English Yeast Started the yeast, .5 cup of DME to a pint of water the night before. Boiled the bottle and boiled the wort for about 15 min. Boiled the top of the pot for the wort, too so that it is sanitary for cooling the wort. OG 1.061 Pot Alc 8 Lower than anticipated gravity. Perhaps I diluted it too much, but it is a solid 5 gal in the fermenter. The wort has a thick heavy maltyness that is nicely balanced by the hops. There is a fruitiness in there, too but not strong. Rose Hips are not strong in flavor anyway. 9/28/01 Racked to secondary. Gravity 1.010. Tastes good, but not done yet. There is a fruity taste, very subtle but it tastes like rose hips. The color is redder than it should be from just the malt. October 2, 2001 Bottled. FG 1.01. This stuff is very good. It has a taste I can't identify and is wonderful. Must make this again. - -------- So there you go. Next fall when the freeze comes, grab some rose hips and try it. It is well worth it. What are these Rennarian Coordinates anyway? John Gubbins n0vse at idcomm.com. Return to table of contents
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