Water pH Query

[cubalz]

I just got my well water pH tested. The results showed it as: 5.95 or 6 if you round it. Just for background, this was done in our lab at work on a calibrated ThermoFisher Scientific system that is dead on accurate as it has calibration verification done pre shift every day.

My question is this: Lately I have been typically brewing all grain American Pale ales, Cream of Three Crops as well as lighter ales lately using Breiss 2 row base malt, specialty grains (Crystal/Caramel) and flaked corn and rice adjuncts for the cream ale.

I am wondering if that pH is optimal for those styles given that I am shooting for a pH between 5.1 - 5.5 in the mash. I do not have a way to check pH in the mash at home and pH strips are unreliable at best. Given my water pH and the typical grain bill, can it be predicted if my mash will be in the correct pH zone? I do not want to add gypsum, acidulated malt, calcium carbonate or sodium bicarbonate if I do not need to.

I have been homebrewing since the late 80's making what I think are great beers but water quality still confuses me and I keep thinking that my beers could be even better with a little more knowledge. The HB forum is my pool of resident experts so I thought I would ask.

Thanks!
John

 

[Gavin C]

The pH value alone tells you little to nothing.

The pH of the water you use is of minimal importance. It's value has minimal impact on mash pH.

The amount of disolved minerals in the water and its pH are useful things to know as you can calculate the alkalinity that way. But again, mash pH is what you need to control.

RO water can have a pH usually between 5 and 6. Same as your water. Two very different water profiles though.

 

[ajdelange]

The pH of a mash depends on how much acid supplied by high colored malts and/or acid additions is consumed in shifting the water from whatever pH it comes to you and the pale malts, from whatever pH's they come to you, to the final pH. Thus the mash pH doesn't depend on the pH's of any of these components but rather the buffering of the malts (mEq/pH-kg) and the water (mEq/pH-L). Where the mash pH is lower than the sample pH that buffering is called 'alkalinity'. In the case of water this parameter is measured between sample pH and pH 4.5 which isn't exactly the alkalinity you want (as 4.5 is below mash pH) but represents perhaps 110 - 120% of the alkalinity to mash pH.

So the pH of the water you measured in the lab is pretty useless information. What you must do is take 100 mL of sample and titrate with 0.1 N acid until pH 5.5 is reached, write the number down and then continue to pH 4.5 and write that number down. The number of cc's are, respectively, the typical mash alkalinity and the official alkalinity that would be found on a water report, both in mEq/L. Multiply by 50 to get 'ppm as CCO3'.