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General Category => All Grain Brewing => Topic started by: bassriverbrewer on February 10, 2011, 09:51:25 PM

Title: Acid rest
Post by: bassriverbrewer on February 10, 2011, 09:51:25 PM
a couple of questions.  I'm brewing a Geman Pils this weekend and wonder if I should do an Acid rest and skip a protein rest. The style guidelins say German pils uses moderate sulfate water for enhancing hop bitterness as opposed to a bohemian pils but it doesn't give a range in ppm as to what that might be.  My water comes from a surface resivoir and they pump river water into it in the winter. I'm using 9lbs pilsner malt 1/4lb aromatic malt and 1/2lb dextrin/carapils a double decocotion mash.
my water report from the city is:
Calcium 20ppm
Magnesium 4ppm
Sodium 40 ppm
Chloride 76ppm
Sulfate 23 ppm
I'm planning on adding gypsum to boost my calcium to around 60ppm which puts my Sulfate around 125ppm or so is that low, moderate or high? The report states the sodium and chloride levels are from salt for deicing the roads. I don't have the carbonate level but I know the water is soft as soap lathers easily and I don't get mineral deposits in my tea kettle like I used to when I lived in Munich
Title: Re: Acid rest
Post by: tomsawyer on February 11, 2011, 12:56:30 AM
I'm no expert but I'd call that sulfate level moderate.
Title: Re: Acid rest
Post by: bassriverbrewer on February 11, 2011, 11:49:26 AM
That's what I figured I just wasn't sure if it would still be i n the low range
Title: Re: Acid rest
Post by: mabrungard on February 11, 2011, 03:15:08 PM
Munich water sulfate concentration is on the order of what your water is, so I agree that your sulfate level is moderate.  The sodium and chloride levels are kind of high, but not excessively so.  I wouldn't add any minerals that increase sodium and be light with any minerals that boosts chloride.  I'd suggest that chlorides be kept below 100 ppm under most conditions.  

You don't need to bring the Ca concentration to 60 ppm, I'd say that 50 is OK.  A combination of gypsum and CaCl might be considered, but keep the Cl below 100 ppm under any case.  

AJ Delange is a big fan of Pils and he is certainly another water expert.  His strong advice regarding sulfate concentrations and noble hops is to keep sulfates as low as possible.  I don't see any reason not to use that advice.  

Carbonate level does not affect the lathering capability of water.  Its the hardness that limits lathering.  From the profile information, it appears that the bicarbonate concentration is around 27 ppm.  This brings the RA for the water to about 58, which is slightly high for a yellow beer.  A very slight addition of acid might be needed to help the mash reach a desirable pH.  I would not perform an acid rest ever.  I would only perform a protein rest if the base malt is undermodified.