How to adjust mash PH

Was at the site hosts store today and bought a digital PH meter. I then asked the staff what was the best way to adjust the mash PH. They told me you can’t adjust the PH once it is a mash. Instead you have to adjust the ph of your water before adding the grains. I am now confused. I thought most all grain brewers checked PH of the mash and adjusted accordingly.

Can PH be adjusted once grains are added to the water?
I have well water.

You can adjust pH in the mash using salts and acids. I find it easier to do the calculations up front using bru’nwater so that if I do need to adjust it’s only by a small amount.

Shadetree,
Pardon the ignorance, but could you explain bru’nwater. I have only made 3 all grain batches.

It’s a spreadsheet, fairly complicated at first, but easy to use after you figure it out. You’ll need a water report on your well water, Ward Labs is a good source (search this forum for info on the right test to use, IIRC it costs ~$15), and then you just follow the directions in the workbook. Once you dial it in, you’ll hit the predicted pH.

The advice you got at the store is just plain wrong. To hit a specific pH target, you must do it in the mash. Chalk, which is the most common brewing salt used to raise pH doesn’t desolve fully in plain water and if you add it ahead of time you’ll leave a lot on the bottom of your water bucket. Chalk only disolves fully once in the mash.

By the way, I use the same method as Shadetree, except I use a different spreadsheet called “EZ_water” which does the same thing. When needing to lower pH for light beer I find that adding a few ounces of acid malt is the easiest way do that.

[quote=“Roddy”]Was at the site hosts store today and bought a digital PH meter. I then asked the staff what was the best way to adjust the mash PH. They told me you can’t adjust the PH once it is a mash. Instead you have to adjust the ph of your water before adding the grains. I am now confused. I thought most all grain brewers checked PH of the mash and adjusted accordingly.

Can PH be adjusted once grains are added to the water?
I have well water.[/quote]

They are absolutely wrong…mash pH is what matters, not water pH. Adding grain to water will change the pH. Before you make any changes at all, you need to understand what’s in your water to make the pH what it it. Get test W-6 from wardlab.com for $16.50. Then download Martin Brungard’s excellent Bru’nwater (https://sites.google.com/site/brunwater/) and input your water values. Then you can input your recipe and use the program to see what, if any, changes you need to make.

+1 to all the above

I really enjoy the bru n water application as well.
In the past you could get your waters residual alkalinity close to the type of beer you
were making premash. IE: low alkalinity for light beers and higher alkalinity for darker beers. See John Palmers book for details behind this method/ model. And then this model would get the water into the right realm to hit a “decent” mash PH and then you would micro adjust in the mash tun with salts, acids or acid malt.

Now some brewers such as Braukaiser (forum name) did some micro mashes and found that as a malt gets darker from roasting or toasting it will contribute more acidity to the mash, Braukaiser also has a website that explains the science he went into to gain this info. Well long story short Martin B created the bru n water app that accounts for the type of grain used in the grist and the base water you have will show you where a Mash PH might be and then you add salts, acids or acid malt into the spreadsheet to adjust up or down to hit 5.3-5.5 PH I have used this app exclusively and now know premash how much salts to add to the grist (premash) and then I add a little acid to the mash once stirred and I have always either hit the 5.4 PH I need or once or twice I have been at 5.5 PH which I will call good and do no more micromanaging in the mash tun.

It makes mashing PH a breeze and I like to plan the day ahead of time so this is all set the night before. One of the above posters mentioned chalk and the inability to dissolve which is correct, I have used pickling lime when I started using the bru n water and am quite happy with the results.
The theory here is that because chalk does not dissolve with CO2 it cannot properly dose the correct amount of calcium and HCO3 whereas pickling lime dissolves great and contributes the right amounts that you will need.

Heres an example that you could punch into the free bru n water suite to see the results:
I made a two hearted clone recently and the grist was the following:
11.5# Rahr two row ( 2 SRM )
1.5# Munich I ( 8 SRM )
0.5# Briess 40L ( 40 SRM )
You enter these amounts and SRMs into the mash acidifaction page.
I used 4.30 gallons of water for the mash, this value is entered on both the mash acidifaction page and the water adjustment page. My batch size was 6.25 gallons entered on the mash acidification page.
My water supply was entered into the water report input page as:
Calcium: 24
Magnesium: 3
Sodium: 17
Chloride: 35
SO4: 21
HCO3: 62
Alkalinity: 51
With a base PH of 8.7

As is without adjustment the mash would hit approximately 5.5 PH as shown on the mash acidification page. But I will have a low calcium mash and my Cl/ SO4 relationship sits in the very malty zone. So I do the following:
Add .20 grams/gallon in the water adjustment page for both gypsum and pickling lime which shows me to use 0.9 grams of each.
This brings my calcium up quite a bit from the pickling lime and the gypsum brings my Cl/ SO4 relationship into a balanced to slightly bitter profile, But if you switch over to the mash acidifaction page you’ll see these two adjustments drove my PH from 5.5 up to 5.8 So now I go back to the water adjustment page and add 2.0 ml/ gallon of Phosphoric acid 10% (available from NB store.) which comes out to 8.5 ml total addition and this shows me on the mash acidifcation page that my mash should hit 5.4PH with the acid addition. Others also use a dose of lactic acid or acid malt in the grist page which all work for this purpose as well I just choose to use phosphoric.

Now also if you fly sparge this application has a sparge adjustment page which will show you how much acid to use to lower your water PH to <6 PH In this particular brew I used 7 gallons of sparge water at PH 8.7 and a Alkalinity of 51 and to bring my 7 gallons of sparge water down to 5.7 PH I use 12 ml Phosphoric acid 10% as shown on the app and it is money trust me.

The other thing I do is within the water adjustment page you can uncheck the box as described on the page as you will see and it shows me how much gypsum I will need to keep the sparge>>>>therefore the kettle runnings in the correct Cl/ SO4 relationship and it shows me to add 1.4 g of gypsum to the sparge water. Some chose to add this right to the kettle along with more calcium but for me I simply add it to the sparge.

HMMM…could not find the edit radio bar?
anywho: “The theory here is that because chalk does not dissolve with CO2”
This should have read “does not dissolve without CO2”

I also highly recommend the EZ Water Calculator. It’s a lot simpler, especially for a beginner, and gives excellent results. Saturday I used it for my Porter, which can be problematic because I have very, very soft water. It’s recommendations predicted a pH of 5.3 and my pH was 5.3 by pH strip, which I corroborated with my lab’s pH meter yesterday.