Difference between reducing alkalinity with acid and hardening? - Home Brew Forums
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Old 02-04-2013, 05:26 PM   #1
hopdoc
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I have been tinkering with my water after finding some information about it. It has 126ppm bicarbonate, and low calcium, and it seems pretty good for brewing darker beers. But, I like pale ales more and am about to brew my first one since learning about adjusting water.

First of all I will be using 100% pale malt.

I am trying to either balance the residual alkalinity with gypsum, or I am going to add acid malt to acidify the mash(or both???). What I really want to know is what the difference is. I already have 26 ppm calcium, so I will definitely add more calcium, but should I use acid malt too? I don't have a pH meter, so it seems easier to just lower the residual alkalinity and not worry about the pH, yet. pH of untreated water is 7.1, by the way...

Another question:
Bru'n Water does not say anything about carbonate. What role does chloride play in brewing water? My report claims less than 1 ppm.

 
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Old 02-04-2013, 06:11 PM   #2
Hermit
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You can use this as it has some profiles to shoot for.
http://www.brewersfriend.com/mash-ch...er-calculator/

You do want to worry about the pH. Brunwater has a page about water that you may want to check out also. If you have the profile then you should just use one of the calculators and get a reasonable guess.

https://sites.google.com/site/brunwater/water-knowledge

 
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Old 02-04-2013, 06:57 PM   #3
ajdelange
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Increasing the cacium content of mash water 1 mEq/L (20 mg/L ~ 50 ppm as CaCO3 ) will result in lowering of residual alkalinity by 1/3.5 = 0.2857 mEq/L ~14.3 ppm as CaCO3 and, under a lot of assumptions, a decrease in knockout pH of 0.024 pH with a, presumably, somewhat smaller reduction is mash tun pH. Under a lot of assumptions that amounts to about 0.2 mEq/L acid produced when part of the calcium precipitates with inorganic malt phosphate. Scaling to 5 gal that's about 3.8 mEq. You would get the same acid (protons) by adding 0.34 mL of 88% lactic acid to 5 gal.

Thus you can lower mash pH with calcium but it takes a lot to get relatively little reduction. Lactic, or other acid, is much more efficient but you have to live with the anion of the acid. Calcium can not usually be relied upon to furnish the needed protons by itself. Acid is required in most cases so the answer is yes, you should probably use acid malt. See the Primer for broad guidelines.

 
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Old 02-04-2013, 07:22 PM   #4
hopdoc
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Thanks for the reply, AJ. I was hoping that you might respond.....

So, if I add the lactic acid, and I add more calcium, would it put me under my desired pH?
What I really want is higher sulfate....

 
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Old 02-04-2013, 07:23 PM   #5
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Quote:
Originally Posted by hopdoc View Post
Another question:
Bru'n Water does not say anything about carbonate. What role does chloride play in brewing water? My report claims less than 1 ppm.
Carbonate does not matter much in brewing water since it only occurs in significant amounts at fairly high water pH. What is your water pH?

You say that your water is high in bicarbonate but low in calcium. Any chance it comes from a water softener? What does the water report look like?

Kai

 
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Old 02-04-2013, 07:38 PM   #6
hopdoc
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pH 7.1
Total Dissolved Solids ppm 185
Electrical Conductivity, mmho/cm 0.31

ppm
Sodium, Na 10
Potassium, K 1
Calcium, Ca 26
Magnesium, Mg 14
Total Hardness, CaCO3 123
Nitrate, NO3-N 6.1 (SAFE)
Sulfate, SO4-S 6
Chloride, Cl 7
Carbonate, CO3 < 1
Bicarbonate, HCO3 126
Total Alkalinity, CaCO3 104

 
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Old 02-04-2013, 07:38 PM   #7
ajdelange
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The wall isn't so hard that calcium is likely to put you under. 200 mg/l might lower mash pH by 0.15 unit so if you were at pH 5.2 from acid and added 200 mg/L calcium (which is, IMO a whole lot) you might go down to close to 5 which most people would consider too low but is probably not ruinous. In most cases you want about 1/4 that much calcium which drops mash pH by around 0.05 or so.

 
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Old 02-04-2013, 07:53 PM   #8
hopdoc
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I am planning on 1.8 grams/gallon of gypsum to bring my sulfate close to 300 ppm, also plan on bringing chloride to somewhere around 50 ppm with calcium chloride. I think the total calcium will be 154 ppm.

This wont bring the pH to around 5.5? After reading the Brun water knowledge page about 50 times over the last week, I assumed it would...

I guess I will add a couple percent acid malt, until I get a pH meter so I can experiment with higher sulfate, and lactic acid additions...

....Or maybe I will just add the minerals as stated above and not worry about it, I have never had a problem getting full conversion, just my pale beer seem watery... 1 dimentional.....

 
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Old 02-04-2013, 08:07 PM   #9
ajdelange
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One can calculate bicarbonate and carbonate from the alkalinity using the pH. For the given data the bicarbonate would be 125.7 and the carbonate 0.09 which is indeed less than one assuming that they measured the alkalinity by titration to end point 4.4.

 
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