Determining the amount of lactic acid to add to sparge water - Home Brew Forums

 Home Brew Forums > Determining the amount of lactic acid to add to sparge water

11-09-2011, 03:59 PM   #1
jmf143
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May 2010
Wixom, Michigan
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Is there a "quick and dirty" method of determining the amount of lactic acid 88% to use to drop sparge water pH by a constant amount i.e. "1 ml of lactic acid in 1 gallon of sparge water will reduce pH by X units"?
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11-09-2011, 05:15 PM   #2
ajdelange
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Aug 2010
McLean/Ogden, Virginia/Quebec
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The amount required depends on the original pH and alkalinity of the water and the pH you want to shift it to. Bru'n water has a calculator.

11-10-2011, 08:27 PM   #3
jmf143
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May 2010
Wixom, Michigan
Posts: 609
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Quote:
 Originally Posted by ajdelange The amount required depends on the original pH and alkalinity of the water and the pH you want to shift it to. Bru'n water has a calculator.
I am aware of this but could have worded my question better. Assume that my tap water pH is 8.1, I'm aiming for a sparge pH of 5.7 and I want to sparge with 6 gallons. Bru'n Water will calculate for the sake of argument 3 ml of lactic acid for me. Can I assume I can always add .5 ml of lactic acid per gallon of sparge water regardless of the grain bill, batch size etc. since 3 ml / 6 gallons = .5 ml lactic acid per gallon of sparge water?
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11-10-2011, 09:01 PM   #4
remilard
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Nov 2008
Kansas City
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Quote:
 Originally Posted by jmf143 I am aware of this but could have worded my question better. Assume that my tap water pH is 8.1, I'm aiming for a sparge pH of 5.7 and I want to sparge with 6 gallons. Bru'n Water will calculate for the sake of argument 3 ml of lactic acid for me. Can I assume I can always add .5 ml of lactic acid per gallon of sparge water regardless of the grain bill, batch size etc. since 3 ml / 6 gallons = .5 ml lactic acid per gallon of sparge water?
Assuming the same water composition and target pH, yes, the amount of acid required is a linear function of the amount of water treated.