Author Topic: Water Report  (Read 888 times)

Offline gmac

  • Brewmaster General
  • *******
  • Posts: 2027
  • London, Ontario
    • View Profile
Water Report
« on: March 17, 2011, 08:40:09 AM »
I was able to track down a water report for our municipal water system.  Could someone please help me interpret the results and what that would mean for brewing?  I think the water is pretty alkaline and pretty hard and thus more suited to dark ales than light lagers but please help me understand what all this means and if any water adulteration is necessary.
Thanks

Edit:  Can't figure out how to attach a PDF, or if that is possible.  Here are some of the parameters, let me know what else I need.

Alkalinity (as CaCO3) - 216
Hardness (mg/L as CaCO3) - 214
pH - 7.8
Sodium - 23.6 (not on the report but communicated so I don't know the units, I am sure mg/L makes the most sense.)
Sulphates (mg/L) - 37
Chloride (mg/L) - 11
Calcium (mg/L) - 38.5
Iron (ug/L) - 169
Copper (ug/L) - 12
Manganese - (ug/L) - 8
Potassium (mg/L) - 1.42
Zinc (ug/L) 10<MDL

Online Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Water Report
« Reply #1 on: March 17, 2011, 09:20:39 AM »
For your hardness, the calcium seems oddly low. However, no Magnesium is given and I have to assume 30 ppm Mg to balance the anions and cations. More Mg hardness than Ca hardness is unusual, but not impossible.

You could get the Mg down with dilution or slaked lime treatment (not the simple process, but one that involves more steps). Boiling would not be able to precipitate Mg.

All that depends on the Mg being a problem. I have seen sources that say up to 50 ppm is acceptable and that the malt adds ~150 ppm anyway. If you don't need to get the Mg down, boiling or slaked lime treatment with the addition of some calcium salts will allow you to create water with fairly low residual alkalinity.

Overall, the water is good for dark beers (could be lagers as well :) ), but for anything lighter you want to look into means of alkalinity reduction.

Kai
« Last Edit: March 17, 2011, 09:23:04 AM by Kaiser »

Offline gmac

  • Brewmaster General
  • *******
  • Posts: 2027
  • London, Ontario
    • View Profile
Re: Water Report
« Reply #2 on: March 17, 2011, 12:05:02 PM »
I should have copied this in before.  This is the comment from the gentlemen who manages our municipal water concerning sodium and magnesium.

Please see attached for additional test results.  The sodium is 23.6 mg/L and is in the online report. The average pH of the water is 7.8. To get the magnesium level you can subtract the calcium from the hardness to give you an approximation.

Not sure if this makes sense.  I will read the section you attached on Alkalinity reduction.  I inquired on another string about Citric Acid and it's use to reduce the pH (I realize I am probably getting pH and Alkalinity confused).  I have been unable to find phosphoric or lactic acid in my limited search to date.

Online Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Water Report
« Reply #3 on: March 17, 2011, 12:45:19 PM »
To get the magnesium level you can subtract the calcium from the hardness to give you an approximation.
That makes sense and you’ll get about the same Mg content if you do it that way.

Quote
  I inquired on another string about Citric Acid and it's use to reduce the pH (I realize I am probably getting pH and Alkalinity confused).
Citric acid’s ability to lower the mash pH is a bit more complicated to calculate. It’s first pKa is 3.13. This means that at a mash pH of 5.5 pretty much all citric acid molecules donated one H+ to lower the pH. But its 2nd pKa is 4.76. This means that at a pH of 5.5 only ~ 80% of the acid molecules donated a 2nd H+ to lowering the pH. At pH 5.7 this number climbs up to ~88%. What this means is that the higher the mash pH the more pH lowering power you’ll get from the citric acid. While this happens to any weak acid (lactic and phosphoric are weak acids) it matters little for the acids that we commonly use in brewing.

So much for the chemistry aspect. I’m not sure on the taste impact of citric acid. The same for acetic acid (vinegar), which I don’t think is used much in brewing either.

Quote
I have been unable to find phosphoric or lactic acid in my limited search to date.

Home brew stores should carry both. You may have to order them on-line. With the gas prices these days the cost of shipping can easily be less than what you spend driving around trying to find them in local stores.

Kai



Offline gmac

  • Brewmaster General
  • *******
  • Posts: 2027
  • London, Ontario
    • View Profile
Re: Water Report
« Reply #4 on: March 17, 2011, 12:57:57 PM »
You're bringing back horrible memories from chemistry class.  pKa?  Haven't heard that term in many, many years.  I was hoping to get through life without ever using chemistry, proving my point that I will never need it so why care.  But now, it appears I should have paid attention 20 years ago.

Thanks a lot for your help.  I'm gonna give the citric a try because I have it already and order some lactic.  There aren't many options around here for homebrew stores (read: none). Most are wine shops which is why they have citric or acid blend (tartaric, citric and malic). 

Guess it will be an experiment.  Not sure how much to add to bring my mash pH in line but last time I did a batch it was about 6.4 10 minutes into the mash which I know is far too alkaline.  I guess I'll just add a bit at a time until I get it down below 6.  And I'll have the baking soda on hand to bring it back up if I really screw it up.
Thanks again for all of your help.

Online Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Water Report
« Reply #5 on: March 17, 2011, 01:29:04 PM »
what concentration does the citric acid have?

For a rough estimate we can assume that each mmol of citric acid will add 2 mEq (2 H+ ions) to lowering the pH. You need about 1.5 mEq per lb of grist to lower the pH by 0.1 units.

Kai

Offline gmac

  • Brewmaster General
  • *******
  • Posts: 2027
  • London, Ontario
    • View Profile
Re: Water Report
« Reply #6 on: March 17, 2011, 10:29:48 PM »
what concentration does the citric acid have?

For a rough estimate we can assume that each mmol of citric acid will add 2 mEq (2 H+ ions) to lowering the pH. You need about 1.5 mEq per lb of grist to lower the pH by 0.1 units.

Kai
I'm afraid there is no concentration on it. It's pretty generic.

Online Kaiser

  • Global Moderator
  • Senior Brewmaster
  • *****
  • Posts: 1797
  • Imperial Brewing Geek
    • View Profile
    • braukaiser.com
Re: Water Report
« Reply #7 on: March 18, 2011, 06:26:48 AM »
 
Quote
I'm afraid there is no concentration on it. It's pretty generic.

I googled it and it seems to come in power form that is mostly 100%. I assume that this powder is a monohydrate (each acid molecule also bound one water molecule) otherwise it would pick up water quickly and starts clumping. But the difference in acid concentration between the two forms is small enough that it doesn’t matter much.

Each mEq acid of this stuff weighs about 100 mg (I’m assuming ~200 g/mol and 2 Eq/mol since I can get mostly 2 H+ at mash pH).

That means that for every lb of grist and every 0.1 pH drop you need about 0.15 g citric acid. For example if you want to drop the pH of a 10 lb malt mash by 0.2 you would need 3g citric acid. Just to be safe, I’d add half of that, test pH and add more if needed.

With your high alkalinity you are facing the same problem that lactic acid face: a lot is needed to get the pH down and too much of it may show up in the taste of the beer. For light beers I think that you should add some (more) calcium to your water and precipitate the alkalinity either with boiling or slaked lime. After that you can use acids to lower the pH of the mash. Since the alkalinity is lower you won’t need as much aid to do that.

Kai




Offline gmac

  • Brewmaster General
  • *******
  • Posts: 2027
  • London, Ontario
    • View Profile
Re: Water Report
« Reply #8 on: March 18, 2011, 07:15:50 AM »
Thanks Kai.
Just curious.  You mention that my water would be OK for darker beers and possibly lagers.  What aspect of darker beers makes this OK?  Or am I mis-interpreting your comments and do I need to adjust pH regardless of the style.  My next brew was intended to be an amber lager (my first lager attempt) using predominantly pilsener malt, a bit of vienna and some crystal 40.  I'm not concerned about the colour as much as the flavour.  My favourite lager is an amber lager from Creemore Springs here in Ontario. 

I won't be brewing now until next week so I will order some phosphoric acid and gypsum (this is the preferred calcium source isn't it?  I can get ground chalk from my local wine store  but I believe that should increase pH).  If I'm waiting for my starter, I may as well order the preferred products for water conditioning at the same time.

I will also be adding 1/4 campden tablet to remove chlorine.  I assume that has little impact on the rest of the water chemistry.
Thank you

Offline hokerer

  • I spend way too much time on the AHA forum
  • ********
  • Posts: 2634
  • Manassas, VA
    • View Profile
Re: Water Report
« Reply #9 on: March 18, 2011, 07:57:31 AM »
You mention that my water would be OK for darker beers and possibly lagers.  What aspect of darker beers makes this OK?

I think the main reason for this has to do with the fact that darker, more highly kilned malts contribute much more towards lowering the mash pH than do lighter malts.  If you've got a bunch of dark malt driving the pH down, then you don't need to add so much in the way of adjustments.
Joe

Offline gmac

  • Brewmaster General
  • *******
  • Posts: 2027
  • London, Ontario
    • View Profile
Re: Water Report
« Reply #10 on: March 18, 2011, 10:34:19 AM »
Does anyone know what citric acid tastes like?  If it's citrusy, unless it's hugely overpowering, would it even be noticeable given the grapefruit characteristic of a lot of the hops that are used these days?  I guess I could just taste some but I don't know if that would be a good reflection of what it would taste like in beer.  I expect it to be sour but after that, no idea.

Offline tschmidlin

  • I must live here
  • **********
  • Posts: 8130
  • Redmond, WA
    • View Profile
Re: Water Report
« Reply #11 on: March 18, 2011, 11:47:09 AM »
Does anyone know what citric acid tastes like?  If it's citrusy, unless it's hugely overpowering, would it even be noticeable given the grapefruit characteristic of a lot of the hops that are used these days?  I guess I could just taste some but I don't know if that would be a good reflection of what it would taste like in beer.  I expect it to be sour but after that, no idea.
Try some sour patch kids, as far as I know they're coated in citric acid and sugar.  I find it very citrusy.
Tom Schmidlin