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Main
Date: 25 Jul 2006 14:00:46
From: rb
Subject: acceptable pH modifiers?
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OK, if I am going to steep speciality grains with water, nothing else, I
think I may need to acidify the water.
according to
http://www.sydneywater.com.au/Publications/_download.cfm?DownloadFile=Reports/TypicalWaterAnalysis.pdf
my water source is Prospect dam, pH 8.0 - 8.4
Depending on style, I generally use around 500g of
crystal/carapils/caramunich grains. I would generally soak in 5 litres
of water, pour off and sparge with another two litres.
From some reading it would seem that common brewing pH modifiers (for
lowering the pH) are gypsum and lactic acid.
My chemistry is pretty much all forgotten. Has anyone got a general rule
of thumb for using either of these?
eg use 1g of gypsum per litre to lower pH from 8 to 6.
Basically I'm guessing I'd want to get the pH down to 6.0 - 6.5
Also other easily acquirable chemicals are
citric acid
tartaric acid
acsorbic acid (vitamin c)
are any of these suitable?
cheers
rb
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Date: 25 Jul 2006 11:06:56
From: Larry Bristol
Subject: Re: acceptable pH modifiers?
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rb wrote:
> OK, if I am going to steep speciality grains with water, nothing else, I
> think I may need to acidify the water.
> [...]
If you're going to go to that much trouble for steeping grains, the best
thing to do (IMO) is adjust the temperature and pH exactly as if you were
doing a full mash. For one thing, it's good practice. But mainly, if it
works for a full mash, then it should work for such a "mini(?) mash".
I don't think anyone could give you a formula like "1g gypsum per liter to
lower pH by n points" because you will have a much higher percentage of
specialty grains. As you know, the relative darkness of the grains has an
impact on the pH, and so it will depend on the type of grain you are
steeping even more than it does when the bulk of your grain bill is pale
malt. The best policy is probably to try it, test it, adjust it.
--
Larry Bristol --- The Double Luck
http://www.doubleluck.com
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Date: 25 Jul 2006 14:31:25
From: John 'Shaggy' Kolesar
Subject: Re: acceptable pH modifiers?
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On Tue, 25 Jul 2006 14:00:46 +1000, <snafu_1@lycos.com > wrote:
> OK, if I am going to steep speciality grains with water, nothing else, I
> think I may need to acidify the water.
Why? It shouldn't really be necessary just for steeping grains. The pH is
critical for the mash, but not really for the steep. The only thing you're
really worried about is extracting tannins, and just keeping the temps
under control should take care of that.
John.
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Date: 25 Jul 2006 05:49:18
From: trequites
Subject: Re: acceptable pH modifiers?
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I'm not sure about adjusting the pH - My water is very soft & I just
modify the water treatment so that it is suitable for brewing beer. It
should then be the correct pH as well.
I treat my water to get the following -
Calcium between 50 and 150 ppm
Mangnesium between 10 and 20 (must be less than 30)
Sodium between 70 and 150
Carbonate less than 50
Chloride less than 250
Sulphate (sulfate) less than 400
I only need to use Gypsum, Epsom Salts and common salt with my water.
A long time ago I worked out the following which I think is right,
although it's many years since I did any chemistry.
For water treatment, the addition of 1 gram increases the ppm of 1
litre of water by the following amounts-
gypsum - 230ppm Ca
gypsum - 560ppm SO4
Epsom salts - 100ppm Mg
Epsom salts - 390ppm SO4
Salt - 400ppm Na
Salt - 600ppm Cl
So, if you're adding to 23litres of water, the addition of 1 gram of
gypsum increases Ca by 230/23 = 10ppm and SO4 by 560/23 = 24ppm etc.
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