Adjusting Mash pH

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Nostrildamus

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I've read my local water report and I see that my water pH is 6.7. I would like to brew an all-grain Koelsch pale ale. which will be made with around 85-90% base malts (Pale and Carapils and maybe some Munich). Aye carumba, to lower my mash pH it looks as though I will have to add a load of Gypsum and/or Calcium Chloride. Somewhere in the neighbourhood of 10-12 tsps for a 5 gallon batch if my calculations (based on JP's How To Brew) serve me correct.

Am I headed for totally rectal annihilation if I add that much?:eek: Should I instead perform an extensive acid rest? If so, how long?

Thanks for helping a new to AG brewer out folks.
 

boo boo

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Your water PH has nothing to do with your mash PH. The different salts present in your water do, however.
It is the salts present in your water that buffer your mash PH. So take it easy with any additions until you check your mash PH and then you can adjust with calcium or chaulk taking in of course the fact that adding chemicals such as salts will affect the final outcome of your beer taste. So take it easy.

Cheers
 

EdWort

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My water pH is 7 and I use 5.2 buffer in my mash. My Kölsch turns out fantastic.

RDWHAHB!
 

Dr Malt

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The source I have found to be the best for understanding and adjusting water and mash pH is John Palmer's book on How to Brew. You can read it on line at www.howtobrew.com. Using your local water analyses, you will have to do some calculating:cross: , but it will get your mash pH in the range you are targeting:ban: . I have very soft water so I can get my pH in the 5.2 - 5.4 range with as little as a 1/4 teaspoon of baking soda. What salts to add and how much, depends on what your water has in it, so check out the information in his book and do the calculation.

Good Luck.

Dr Malt:mug:
 
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Nostrildamus

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Yup, read JP's How To Brew and I'v read my water report and looked at Ca and Mg concentrations versus my pH and done the requisite calcs. Maybe they're off... way off.

I know water pH has nothing to do with mash pH other than your water pH being the starting point. Considering distilled water has a pH of 5.7-5.8 and JP states that a mash made with all base malts and distilled water equals the same then I would assume that I would have to lower the pH with additives and/or an acid rest. Correct?

Do you guys use litmus strips and check your pH that way?
 

Lil' Sparky

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The easy way is going to be using the 5.2 pH buffer. Mix it in the mash and it does the rest, allowing you to RDWHAHB. ;)
 

Bearcat Brewmeister

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I wouldn't use just plain distilled water because its pH is close to what you want before base malt is added. The natural magnesium in tap water is needed by the yeast for proper metabolism, so at a minimum you should add epsom salts and then baking soda to balance the pH drop it provides.

Some tap water has a pH up to 8 and adding the base malt is what drops it to 5.8. I am not an expert on this and need someone to confirm, but I would think that adding base malt to distilled water would drop it below 5 since there is nothing to buffer it.
 
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Nostrildamus

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Agreed... I won't be using distilled water and had no intention I was just citing it as it appeared that it plus base malt would still result in a mash pH of the original distilled water. I was under the impression from that info that maybe base malt was not affecting the pH in any way.

I actually had no idea that there was such thing as a pH buffer solution! I'll ask at my LHBS about its availability. It sounds like an easy situation to a vexing problem.

In any case, rather than getting too over the top when it comes to the calcs and numbers of brewing I probably just ask my local HB guru and see what he says I should do. I just love getting into the nuts and bolts of brewing and like to rip things apart into fine detail.

Thanks again HBT forum folk!:rockin:
 

Evan!

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Word---even if your LHBS doesn't carry it, you can get it online. I got mine from Austin.

edit: damn, sparky, too quick...
 

pjj2ba

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Unless you have particularly hard water or are trying to match a particular water style, you really don't need to worry that much about pH. With regards only to starch conversion, A couple of points:

RO/distilled water has NO real pH!!!!!!! pH is the H+ ion concentration - which there is none of in truely pure water. A pH meter will still give you a reading, and so will various pH papers but they are not giving a true reading. In Theory it should be 7.0 as the concentrations of H+ and OH- are equal (at 0).

Now add a tiny bit of anything with an H+ or OH- and you will get an accurate reading. Adding NaCl for instance will not affect the pH, nor will CaCl2, but CaSO4 will (Sulfate "reacts" with water to give H+ ions). You can add a couple drops of acid and the pH will drop very quickly, but if the concentration is low, it does not take very much of a base to bring it back up. In this case there is very little BUFFERING CAPACITY. THIS is what one needs to pay attention to, not the actual pH. Soft water has little buffering capacity and has the least affect on mash pH. Hard water has a greater buffering capacity and can cause some problems if the water is very hard.

Assuming you have typical water, the pH of the mash is mostly due to the grains you've added, not the water (unless you mash with a high water to grain ratio). The malts are loaded with organic acids, and these are largely responsible for the mash pH. Fully modified malts have a pretty high buffering capacity. Remember the seed is using the same enzymes we're taking advantage of for brewing, to breakdown starch to feed the growing shoots and roots. The seed has set up the components to give it the best pH for it's own starch metabolism (like the acid in our stomach) and we just take advantage of that.

If you fly sparge, as you drain off the wort, you are also draining off the organic acids that are buffering the mash at the proper pH. In this case, towards the end of the sparge your water will have a significant affect on mash pH when the natural organic acid levels go below that of the buffering capacity of your water. If you have problematic water, this is where I'd worry about adjusting pH.

For Batch spargers this is much less of a concern as you aren't contiunally diluting the organic acids.

There are styles where the mash pH should be adjusted to get the proper taste (ie. Berliner Weisse), but I think for most homebrewers, for most beer styles, this is not a big problem.

Of course the water has a big affect on the final taste, but this has more to do with the salts, and not the pH of the mash and starch conversion. The salts in the water have a big impact on hop flavors

From Five Star, the makers of 5.2,
Optimizing the enzymatic activity of your malt
Helping clarify your wort
Obtaining more consistent hop usage in the boil
Reducing scaling & mineral deposition in all your equipment
Brewing more consistent beer!
I've been messing around with this stuff, but not for the first reason listed. My water is a bit high in carbonates and when I added 5.2 to my water and heat it up, it turns cloudy. It is a known fact the Ca will react with phosphate (5.2's main component) to form an insoluble salt so I believe this is why it is cloudy. I "think" also that this may mess up the carbonate equilibrium and result in lower carbonate levels. I need to do more reading to confirm this. I'll know the results in another week what the affect of my experiments with 5.2 are.
 

Lil' Sparky

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pjj2ba - really nice explanation. You sound like you know what you're talking about.

We've got off-the-chart bicarbonate levels here (459 ppm) and almost no Ca or Mg. I've been using lactic acid to bring down the alkalinity and then adding the buffer and let it stabilize where it's supposed to. I do this because I don't know if the buffer is strong enough to handle that kind of residual alkalinity. Since I've been doing this, I've eliminated the astringent bitterness I had in a few of my beers after we moved here.

pjj2ba said:
I've been messing around with this stuff, but not for the first reason listed. My water is a bit high in carbonates and when I added 5.2 to my water and heat it up, it turns cloudy. It is a known fact the Ca will react with phosphate (5.2's main component) to form an insoluble salt so I believe this is why it is cloudy. I "think" also that this may mess up the carbonate equilibrium and result in lower carbonate levels. I need to do more reading to confirm this. I'll know the results in another week what the affect of my experiments with 5.2 are.
A few questions:

Were you trying to say that the salts formed when it turns cloudy is bad? I can't really taste a difference.

And explain the "mess up the carbonate equilibrium" part. I do in fact want to lower the carbonate levels to bring down the mash pH.
 

pjj2ba

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Lil' Sparky said:
Were you trying to say that the salts formed when it turns cloudy is bad? I can't really taste a difference.

And explain the "mess up the carbonate equilibrium" part. I do in fact want to lower the carbonate levels to bring down the mash pH.
No, cloudy is not bad at all! The salts probably won't end up in the fermenter as they get trapped in the grain bed and/or hot break. It tells me that I'm somehow adjusting my water.

Below is from an article I found, which unfortunately was a PDF that wouldn't load but I could view in HTML so I pasted a copy (totally lost all formating ) into Word

There are several ways to reduce residual alkalinity:

1. Neutralize the bicarbonate by the addition of mineral (usually hydrochloric, sulfuric or phosphoric) or organic (usually lactic) acid.

2. Remove the bicarbonate.

3. Dilute the bicarbonate.

4. Increase calcium and or magnesium thus releasing malt acid which neutralizes the
bicarbonate

In Part I, I discussed how the relative proportions of each of the three carbo species (carbonic, bicarbonate, carbonate) depended on the pH of the water.

Calcium carbonate is not very soluble in water so that if the pH becomes high enough that the relative concentration of carbonate ion increases and if calcium is present insoluble calcium carbonate forms and drops out of solution. When some calcium carbonate precipitates the equilibrium between bicarbonate and carbonate is upset as there is proportionally less carbonate. This causes some bicarbonate to convert to carbonate in an attempt to rebalance the proportion. This results in release of
hydrogen ions which tends to lower the pH. Lowering of the pH causes some bicarbonate to convert to carbonic, consuming some of the hydrogen ions and raising the pH.
So what does all this mean....... It suggests to me that you can change the carbonate levels by manipulating the pH. I don't have enough information yet to fully understand, but I believe the presence of Ca and a low enough pH will lead to less carbonate. I'm hoping that the cloudiness I see is partly some insoluble CaC03, in addition to the CaPO4 I know is there.

Other than Carbonates, your water looks fairly soft. Based on the article, adding some Calcium should help reduce carbonate levels. If I remember correctly, CaCl2 is used for maltier flavors and CaSO4 for hoppier flavors (or vice versa). In this case CaCl2 might lower your pH, contrary to what I said above. Both are correct. Dissolve CaCl2 in pure water and it won't change the pH. Add it to water with carbonate in it and it will react with the carbonate and change the pH
 

Lil' Sparky

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I think I've got a handle on it. I've read Palmer's book, worked up the numbers on his nomographs and spreadsheet, and had an email conversation with him about it. You just said a few things I didn't quite understand.

I could just add enough lactic acid, but I like the idea of letting the buffer get it exactly right. I only use about 1/2 the lactic acid that it would take to totally bring down the residual alkalinity, and then add the buffer to the mash.
 

cpbergie

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So does adding the 5.2 buffer make everything ok? My water is low in Calcium, so I add gypsum. Would i get the same effect with just letting the buffer do its work on the PH?
 

Lil' Sparky

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Yes, the buffer would take care of it for you. Unless you're using a chart and adding a specific amount of gypsum based on water report, or testing the pH of your mash, you're just taking a guess if what you're adding is right. The buffer would nail the pH, regardless of grain bill, and take the guess work out of it.
 

Bearcat Brewmeister

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One more note: OP is probably correct that his distilled water measured a pH of 5.7. At the moment it is distilled, it is at 7.0 but if it is exposed to air, it will begin to absorb CO2 from the air:

CO2 + H2O -> HCO3- + H+

which lowers pH. At atmospheric pressure, carbon dioxide will dissolve into water and eventually reach equilibrium. At that point the pH will be 5.7. You can even get it lower by adding CO2 pressure (the reason carbonated water tastes acidic).
 

pjj2ba

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Bearcat Brewmeister said:
One more note: OP is probably correct that his distilled water measured a pH of 5.7. At the moment it is distilled, it is at 7.0 but if it is exposed to air, it will begin to absorb CO2 from the air:

CO2 + H2O -> HCO3- + H+

which lowers pH. At atmospheric pressure, carbon dioxide will dissolve into water and eventually reach equilibrium. At that point the pH will be 5.7. You can even get it lower by adding CO2 pressure (the reason carbonated water tastes acidic).
Bearcat is right! Another item mentioned in the article is that left exposed to the air, the water will eventually lose most of the carbonate in order to set up an equilibrium with the CO2 in the air. I'm not sure what the time frame is. It might not be that bad. If one was inclined to plan in advance (not me) one could put all of the water they'll need in an open container, the more surface area the better, and add an aquarium pump and air stone to speed it along. I bet you could get significant carbonate reduction overnight with no additions.
 

Got Trub?

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Lil' Sparky said:
Yes, the buffer would take care of it for you. Unless you're using a chart and adding a specific amount of gypsum based on water report, or testing the pH of your mash, you're just taking a guess if what you're adding is right. The buffer would nail the pH, regardless of grain bill, and take the guess work out of it.
You can also use the Palmer nomogram or calculate it using your known water chemistry. I do the latter with a spreadsheet. I can predict my pH and see if it is going to be a problem based on my grain bill and adjust accordingly. I can also easily modify my water to approximate various "waters of the world" when brewing a certain style.
 
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