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Path: utzoo!decvax!decwrl!glacier!Shasta!pae
From: pae@Shasta.ARPA
Newsgroups: net.wines
Subject: Re: Brewing Beer
Message-ID: <18@Shasta.ARPA>
Date: Thu, 30-Jan-86 13:47:43 EST
Article-I.D.: Shasta.18
Posted: Thu Jan 30 13:47:43 1986
Date-Received: Fri, 31-Jan-86 03:10:41 EST
References: <365@watmum.UUCP> <139@slu70.UUCP> <347@opus.UUCP> <627@amiga.amiga.UUCP>
Reply-To: pae@Shasta.UUCP (Peter Eichenberger)
Distribution: na
Organization: Stanford University
Lines: 24

tomp@stella.UUCP (Tom Pohorsky) writes:
>Agreed! This microb's contamination thing IS very important. My experience
>has been w/bottling wine, and with all the aging and such it's a serious
>issue. The standard solution w/wine is to add a tiny amount of sodium 
>bisulfate [sic.]. Human taste threshold is ~ 200 ppm; most wineries and
>successful home winemakers use 100-150. Sodium metabisulfide [sic.] can also be
>used in pretty much the same way. These are available at most wine/beermaking
>supply houses.
>  All this chemical abuse may sound unappealing, but the wine world has been
>doing it for along time with good results. If you're aging beer a long time,
>and/or your intended cleanliness is not fully successful, you might want to
>give this a try.
>  
No, you don't want to use Sodium bisulfite (not ...fate) or Potassium 
metabisulfite in beer.  They are both just sources of SO2 (sulfur dioxide)
whose antimicrobial action is a function of pH (a measure of acidity).
Wine has a low pH (more acid) and so the SO2 is more effective and so less
is needed.  Beer has a much higher pH and so 10 to 100 times as much SO2
or bisulfate salts would be needed.  Clearly not desirable!

-Peter Eichenberger

P.S. roughly, the amount of SO2 required is (1+10^(pH-1.8))*.8 ppm.
    Wine pH is from about 3.2 to 3.7.  Beer (I think) is from about 5 to 6.