Author Topic: Yeah, the 5.2 stuff. Don’t get me started on that.  (Read 2682 times)

Offline Kirk

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Yeah, the 5.2 stuff. Don’t get me started on that.
« on: January 29, 2011, 05:01:58 PM »
I'm one of those guys and want to quit.
I'm brewing next Friday, so I probably don't have enough time to get a report from Ward Labs. 
But, I have a brand new toy (a PH meter) and an old toy (a HTH water testing kit).  Today, I did a sample test:
Total Hardness: 60 ppm
Total Alkalinity: 60 ppm
PH: 7.86
It's good tasting water.  The local microbrew doesn't do much to theirs. (At least that's what they told me).
Usually, I start with about 7 gallons of mash strike water, and 14 gallons of HLT sparge water.
If you were brewing a Pilsener, what would you add?  How about for a Black?  An amber?  and so on.
I don't want to fine tune it too much.  I just want to know what stuff to have on hand, so I can add until the PH is right.
I hope it's not too much more complicated than that.  Ball park estimate, that's all.
Kirk Howell

Offline Tim McManus

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #1 on: January 29, 2011, 07:32:04 PM »
If you like the beer you brew, who cares?  Your water is nearly neutral and you should be able to brew some decent beers with it.  It might be soft, and that should lend itself to lighter beers.

If you want to win competitions, then you might want to delve more into water chemistry.  You haven't given enough information to help adjust for a Pilsner profile or any other beer profile.
Tim McManus
Haskell, NJ

Offline tom

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #2 on: January 30, 2011, 08:46:39 AM »
First, check the mash pH. If it is 5.2-5.5 you won't need to do anything.

For very pale beers you may need to add some acid (typically phosphoric or lactic) or calcium (chloride or sulfate) to bring down the pH.

For very dark beers you may need to add some CaCO3, NaHCO3 or Ca or NaOH to raise the pH.

Then (now?) get a water report from your local water board or send for a Ward water report.

I found that John Palmer's book How To Brew helped me understand the mash pH. You can review the chapter at  : http://www.howtobrew.com/section3/chapter15-3.html The spreadsheet at the bottom is an easy plug-in way to alter your residual alkalinity for any beer. It is very accurate in my experience.
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Offline euge

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #3 on: January 30, 2011, 11:59:42 AM »
You water pH isn't what matters. In fact it's irrelevant. The mash pH is not... And that'll be affected by the minerals already present in the water and by the type of grain you're using.

Never really hear of people using that product very much, and have been cautioned that it doesn't always work. Hopefully you have that "average" miracle water that allows you to brew most types of beer.

I highly recommend listening to the 4 part series on water given by Jamil Zainasheff and John Palmer on the brewing network.

http://thebrewingnetwork.com/shows/Brew-Strong/Page-5
The first principle is that you must not fool yourself, and you are the easiest person to fool. -Richard P. Feynman

Online Kaiser

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #4 on: January 30, 2011, 07:01:16 PM »
You seem to have good starting water. Hardness and alkalinity are fairly low. Sodium, chloride and sulfate remain unknown, but lets assume they are low too.

Having a pH meter also helps you to check the effectiveness of the water treatment.

For hoppy beers you may want to add 0.75 g gypsum to every gallon of water. This will boost the calcium content to about 60-70 ppm.

Very pale beers, pilsners for example, may also benefit from about 2% acid malt in the grist.

Dark beers, like stouts, would benefit from 0.75 g chalk and 0.3 g baking soda per gallon of water. This should keep the pH from dropping too much.

Obviously these are just starting points and the topic can get much more complicated than that.

Kai

Offline tomsawyer

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #5 on: January 31, 2011, 09:11:18 AM »
+1 for Kai's recommendation.  I'd add gypsum for calcium and sulfate, and I use lactic acid to bring the pH in the right range.  since you have the pH meter theres no sense in guessing what it'll take, just add the gypsum to the strike water, mash in and then check pH and add acid accordingly.  I'd give it a good stir before each test and only add a ml or two each time.  Be sure you know what the right pH range is for your measurement (room temp vs hot).
Lennie
Hannibal, MO

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #6 on: January 31, 2011, 10:04:11 AM »
since you have the pH meter theres no sense in guessing what it'll take, just add the gypsum to the strike water, mash in and then check pH and add acid accordingly.  I'd give it a good stir before each test and only add a ml or two each time. 

FYI, It should take about 0.25 ml of 88% lactic for every kg of grist to lower the mash pH by 0.1 pH units. That’s ~0.1 ml for every pound of malt.

Kai


Offline tomsawyer

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #7 on: January 31, 2011, 11:25:08 AM »
So for a 10lb grist if you need to go from 5.8 to 5.4, you'd need 4ml.
Lennie
Hannibal, MO

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #8 on: January 31, 2011, 11:47:47 AM »
So for a 10lb grist if you need to go from 5.8 to 5.4, you'd need 4ml.

Yes, that’s what I have seen in experiments. I’m currently in the process of compiling observations I made during brewing actual batches to see how well this matches the more controlled experimental environment.

I’m right now looking at a log book entry for a Weissbier where I started out with pH 5.83. After 2 ml 88% LA I got pH 5.63 and after another 2 ml I got pH 5.48. The total grist weight was 8.9 lb (4 kg).

Kai

Offline tom

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #9 on: January 31, 2011, 01:34:17 PM »
Same with phosphoric 88%?
TIA, Tom
since you have the pH meter theres no sense in guessing what it'll take, just add the gypsum to the strike water, mash in and then check pH and add acid accordingly.  I'd give it a good stir before each test and only add a ml or two each time. 

FYI, It should take about 0.25 ml of 88% lactic for every kg of grist to lower the mash pH by 0.1 pH units. That’s ~0.1 ml for every pound of malt.

Kai


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Online Kaiser

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #10 on: January 31, 2011, 02:10:30 PM »
Same with phosphoric 88%?
 

Pretty much, since lactic acid and phosphoric acid have about the same molaric weight. I haven’t tried phosphoric acid in an actual batch of beer yet.

Kai

Offline tomsawyer

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #11 on: January 31, 2011, 03:17:57 PM »
Phosphoric is a stronger acid than lactic.  Lactic is a carboxylic acid and doesn't dissociate as completely, its pKa is 3.86.  Phosphoric acid has a pKa of 2.15.  Since this is a log scale, I think it means the phosphoric is 10X more acidic than the lactic.

More importantly, Palmer says that phosphoric acid precipitates out as calcium phosphate, messing up your calcium level.
« Last Edit: January 31, 2011, 03:24:04 PM by tomsawyer »
Lennie
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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #12 on: January 31, 2011, 05:19:10 PM »
Phosphoric is a stronger acid than lactic.  Lactic is a carboxylic acid and doesn't dissociate as completely, its pKa is 3.86.  Phosphoric acid has a pKa of 2.15.  Since this is a log scale, I think it means the phosphoric is 10X more acidic than the lactic.

Lennie,

That doesn't matter much. Lactic acid having a pKa of 3.86 means that at 4.86 10% of the lactic acid molecules have not yet released hydrogen ions and thus not contributed to lowering the pH. At pH 5.86 only 1% has not yet released hydrogen ions.

In the case of phosphoric acid 10% have not donated their hydrogen ions at pH 3.15 and 1% haven't donated them at pH 4.15.

This means the difference in "acidic power" between these acids at commonly used mash pH values is a few percent and not something we have to worry about.


Quote
More importantly, Palmer says that phosphoric acid precipitates out as calcium phosphate, messing up your calcium level.

I have heard that as well. I think he is just postulating this w/o having done experiments on it. The amount of phosphate added to the mash with phosphoric acid additions is small compared to the phosphate that is already in the malt. In addition to that the limiting, i.e. controlling, substance in the calcium-phosphate reaction, that release hydrogen ions, is the calcium and not the phosphate.

A while back I posted results from adding varying amounts of phosphoric acid to the mash and I found that the final change in pH is similar to what I got with lactic acid when plotted over the mEg/kg acid added:

http://www.homebrewersassociation.org/forum/index.php?topic=5381.0

Kai
« Last Edit: January 31, 2011, 05:22:09 PM by Kaiser »

Offline hopfenundmalz

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #13 on: January 31, 2011, 05:55:28 PM »
Phosphoric is a stronger acid than lactic.  Lactic is a carboxylic acid and doesn't dissociate as completely, its pKa is 3.86.  Phosphoric acid has a pKa of 2.15.  Since this is a log scale, I think it means the phosphoric is 10X more acidic than the lactic.

More importantly, Palmer says that phosphoric acid precipitates out as calcium phosphate, messing up your calcium level.
OK - I have not Googled it, but can you explain to a dumb engineer what pKa is with the acids?

The little chemistry that I had was in another universe, a long long time ago...
 
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Online Kaiser

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Re: Yeah, the 5.2 stuff. Don’t get me started on that.
« Reply #14 on: January 31, 2011, 06:32:05 PM »
OK - I have not Googled it, but can you explain to a dumb engineer what pKa is with the acids?

It's a somewhat complicated topic, but let me give it a try.

pKa is a property of weak acids which are acids that do not necessarily donate all their hydrogen ions to their environment. The pKa refers to the pH at which 50% of the acid molecules donated their hydrogen ions and 50% haven't not donated them yet. At a pH lower than the pKa more molecules will hold onto the hydrogen ions and a pH higher than the pKa more molecules will have lost their hydrogen ions. Donating and accepting hydrogen ions reversible and is controlled by the pH of the environment.

Only those hydrogen ions that have been released will be able to contribute to lowering the pH. In our case only an acid that has a pKa lower than the desired mash pH will be effective a lowering the mash pH since only then the majority of its molecules will donate the pH lowering hydrogen ions to the mash.

Both lactic acid and phosphoric acid qualify for that.

A strong acid, like hydrochloic acid, has a pKa so low that all its molecules have donated their hydrogen ions. This allows these acids to be as aggressive as they are. But they are no stronger at lowering mash pH as other acids are as long as the pKa of these acids is sufficiently lower than the mash pH range.

Kai