FORUM ON BEER, HOMEBREWING, AND RELATED ISSUES Digest Janitor: pbabcock at hbd.org *************************************************************** THIS YEAR'S HOME BREW DIGEST BROUGHT TO YOU BY: Northern Brewer, Ltd. Home Brew Supplies Visit http://www.northernbrewer.com to show your appreciation! Or call them at 1-800-681-2739 Support those who support you! Visit our sponsor's site! ********** Also visit http://hbd.org/hbdsponsors.html ********* Contents: Re: yeast starter step sizes (Hubert Hanghofer) Trying to find Jever Pils in Richmond, VA (Scott Alfter) Sweet stout - how much lactose (Signalbox Brewery) Beer and Beer's Law (was: Color Extraction) (J A Stephen Viggiano) Brewing with hemp seeds - use crushed or whole? ("Oisin Boydell") Beer's law and linearity (Nathaniel Lansing)
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---------------------------------------------------------------------- Date: Fri, 01 Sep 2006 00:09:26 +0200 From: Hubert Hanghofer <hubert at netbeer.org> Subject: Re: yeast starter step sizes Philip wrote: > I have been thinking about the post below for several months, > and have a question. > > Full post > <http://hbd.org/hbd/archive/4965.html#4965-5> > > > Given the last sentence from the excerpt, why don't we acidify > starters to a pH of 4 or so? > Yeast will do that for you - it drops pH to equal or less than 4.5! I think the key here is to keep yeast at exponential growth - hence 5 fold (lager yeast) or 10 fold (ale yeast) dilution at the right timing (high krausen). If you have a bacterial contamination (we always have) and IF that bacteria are well adapted to your wort (...can take month, but if you've the wrong hygiene procedures it WILL happen!!) then that bacteria will multiply maybe 10 times faster than yeast during exponential growth. BUT yeast is 1000 times bigger by volume & mass than the average bacterial bug (assuming a diameter ratio of 10:1 - like 5um : 0.5um). So with regard to growth in biomass bacteria have no chance! They'll succeed eventually after yeast has reached stationary phase - IF the conditions are still hospitable for their growth by then - wich is only true maybe for a fraction of a percent compared to the bacterial variety that can growth in virgin wort. So my point: Keep yeast at exponential growth right from inoculation of starter to primary. But what I often do is acidifying harvested yeast to kill 99.99% of bacterial contaminations. 30 grams of solid citric acid crystals per litre of yeast slurry (sorry, I'm metric) will drop pH down to 2ish. Keep it cold (fridge temps), stirr often and don't extend the treatment longer than 2 hours. If the yeast is flocculant at low pH you can wash it by slurrying it repeatedly in citric acid solution (30grams per litre water). Pitch immediately after the treatment - don't store acid washed yeast! EBC's "Manual of good practice" recommends not to wash out the acid prior to pitching - I do, but my brain is damaged by reinheitsgebot - never had a bad result though ;-) I've learned this from a brewer in Scotland (Harviestoun - a few years ago when the brewery still was located in an old byre). They maintain their own yeast culture. After growing a fresh starter they repitch 15 times and acid wash each time (probably not with citric acid but with sulfuric or phosphoric acid). Their beers are yummy - you've to taste "Old Engine Oil" stout! This is their yeast propagator: http://album.bierig.org/showimg.php?file=/2003/Edinburgh/IMG0029.jpg and this is 2 views of their former location in the "old byre": http://album.bierig.org/showimg.php?file=/2003/Edinburgh/IMG0026.jpg http://album.bierig.org/showimg.php?file=/2003/Edinburgh/IMG0028.jpg Cheers Hubert, Salzburg, Austria - quite a few thousand miles east of Jeff Renner. Return to table of contents
Date: Fri, 01 Sep 2006 17:48:07 -0700 From: Scott Alfter <scott at alfter.us> Subject: Trying to find Jever Pils in Richmond, VA It's my father's favorite, and he had heard from someone that there's a store somewhere in the Richmond area that carries it, but he can't remember which store and I didn't find anything in my searches. (The only place I've seen it on this side of the pond is Chevy Chase Liquors in DC, but that's a fair bit up the road.) Does anyone know where one might find six-packs or cases of Jever Pils in or near Richmond? Scott Alfter scott at alfter.us Return to table of contents
Date: Sun, 03 Sep 2006 13:13:57 +0100 From: Signalbox Brewery <signalbox.brewery at ntlworld.com> Subject: Sweet stout - how much lactose I made a sweet stout following the instructions in Wheeler's "Homebrewing" - 125g/25-l - ie about 3 1/2 oz per 5 US gal and the sweetness was barely noticeable. Daniels quotes this figure too in Designing Great Beers. Turning to Derek Walsh's Biertypengids, I find 9% quoted. 650g/25l or 1lb/5US gal. That figure ties up with Wheeler's later book "Brew Classic European Beers at Home". However Walsh gives that as a reference so maybe he just took it from there. So, my question is for those who have actually made a sweet stout(!) How much do you use? David Edge, Derby UK Return to table of contents
Date: Mon, 4 Sep 2006 15:27:09 -0400 (EDT) From: J A Stephen Viggiano <jav9729 at cis.rit.edu> Subject: Beer and Beer's Law (was: Color Extraction) In archive 5046, on 19 August, A.J deLange asserted that "beer doesn't follow Beer's law". Or, more precisely, I suppose he repeated this assertion. So it's not my intention to single out A J; many people have repeated what experimental evidence has shown to be an urban legend. I had recently looked into this very question, and have determined that if the beer is free of visible turbidity, it does indeed obey the Bouguer-Lambert-Beer law (to give it its full name). What I did ascertain was that if a beer had an absorbance greater than the spectrophotometer was able to reliably measure, special procedures were necessary. I used attenuation of the reference beam in Varian Cary 500 and Shimadzu UV-2100-series instruments, together with a slight increase in the slit width and a reduction in scan speed (which, presumably, would permit longer integration times). If you're interested, I can post to my website an absorbance spectra plot for Beamish Stout at five different concentrations: 20%, 40%, 60%, 80%, and 100%. Aside from the very shorter (bluer) wavelengths, below 400 nanometers, where the absorbance of beers is highest and the signal level was often exceeded by the noise, the absorbance spectra divided by concentration all fall on top of each other, just as the Bouguer-Lambert- Beer law says they should. If someone tells you a liquid does not follow the Bouguer-Lambert-Beer law, ask them (a) what is the maximum spectral absorbance they're measuring; (b) what is the maximum spectral absorbance at this wavelength for which a standard solution, such as potassium permanganate, also appears to conform on their instrument; and (c) what does the manufacturer's specifications say about maximum absorbance at this wavelength for the slit size and scan speed they used. Also, if they seem to be confused about the relationship between transmittance and absorbance (A = -log_10 (T), not log_10 (100 * (1 - T)), as one famous beer author seemed to imply), ask to see their numbers. ==John Return to table of contents
Date: Tue, 5 Sep 2006 09:15:19 +0100 From: "Oisin Boydell" <oisinboydell at gmail.com> Subject: Brewing with hemp seeds - use crushed or whole? Hi, I'm going to brew a stout with hemp seeds based on a recipe in an old issue of BYO magazine ("Brewing Hempen Ale" by Steve Nordahl, July 1999, p. 34.). I'm going to try the partial mash version and the instructions for using the hemp seeds are: "Place hemp seeds on a cookie sheet and roast in a 450 F (232 C) oven for 30 minutes. Heat 1 1/8 gallons (4.3 L) of water to 167 F (75 C). Place crushed grains and hemp seeds in a steeping bag and submerge bag in this water. Steep for 45 minutes, holding temperature around 156 F (69 C)". The recipe calls for 1.5 lbs. (0.68 kg) mild hemp seed - the type you can buy in health food stores. My question is do I crush the hemp seeds (after roasting), or just use them whole? Its not clear from the instructions whether its just the grains that are crushed or both. Does anyone have any experience brewing with hemp seeds? Thanks, Oisin. Return to table of contents
Date: Tue, 5 Sep 2006 09:03:44 -0400 From: Nathaniel Lansing <delbrew at compuserve.com> Subject: Beer's law and linearity OK, so now we have established that the measurements are accurate and linear, how does this apply to perceived beer color? Does a beer that measures 10 SRM appear twice as dark as the beer that measures 5 SRM? or conversely does the 5 SRM seem twice as clear as a 10 SRM? since eyes respond to light rather than black. I have found various statements saying eyes operate in a logarithmic fashion to illumination, and other source say that eyes operate to the 0.4 power to increasing illumination. The original Lovibond method was a visual comparison method for describing wort color. So the question comes up is it the problem of applying a linear laboratory method to a nonlinear visual response that causes the divergence between systems? Lovibond made a system that if a malt rated 4 was used it created wort that *appeared* twice as dark as wort that was a 2L; so how would that have actually measured? Return to table of contents
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