Mash pH, how important is it??

[Paul86]

I know what to expect from certain levels of Alkalinity and calcium chloride and sulphate additions. The mash looks good, converts in a reasonable amount of time, the yeast floats and then flocculates, and the finished beer has a great head and clarity. That's good enough for me. The pH is clearly within a reasonable range.

I acidify all my brewing liquor first, not to a specific pH, but to a certain Alkalinity. Then, provided that Palmer, Kaminsky, etc etc are correct, it should all go nicely from there.

Anything with only pale malts gets dropped to 10 to 20 ppm Alkalinity, then progressively more alkaline as I brew darker, up to 100ppm or so for a stout (if I mash the roast, which I do).

Hope that helps. My way and the pH meter way are, of course, complimentary, I just don't bother with the second part.

Sorry, and I use CRS for bitters, lactic acid for stouts.

Thanks for the Info Tom I recently bought a vial of Lactic Acid for a choc oatmeal stout I plan to brew. Fingers crossed this one turns a bit better than my more recent attempts.

[Tom]

There's not much info on the accurate dosing of Lactic acid, so I spent a couple of hours and many, many cups of tea, figuring out the following, and I've checked the sums, and I've road tested it. I'm happy enough to share this with y'all:

Alkalinity reduction using 80% Lactic Acid (HBC strength)

Alkalinity to be reduced (ppm) x volume (litres) = ________
Multiply the answer by 0.00186, answer in mls.

For example, I have 370ppm alkalinity (which I bloody do, damnit) and I want 100ppm. So I need to reduce 270ppm. I will be treating 30 litres of water.
270 x 30 = 8,100 mg of alkalinity.
8,100 x 0.00186 = 15ml Lactic Acid.



Dose the brewing liquor at the start, if you can, as it's easier. The alkalinity reduction will mostly take place in the mash tun, the same as phosphoric acid. Sulphuric and Hydrochloric reduction will take place in the HLT.

[imark]

There's no point having a pH meter unless you calibrate it with buffer solutions regularly. If you aren't doing this then your readings aren't reliable.
In my experience you need to do this each week or brewday. Whichever is first.

[Paul86]

There's not much info on the accurate dosing of Lactic acid, so I spent a couple of hours and many, many cups of tea, figuring out the following, and I've checked the sums, and I've road tested it. I'm happy enough to share this with y'all:

Alkalinity reduction using 80% Lactic Acid (HBC strength)

Alkalinity to be reduced (ppm) x volume (litres) = ________
Multiply the answer by 0.00186, answer in mls.

For example, I have 370ppm alkalinity (which I bloody do, damnit) and I want 100ppm. So I need to reduce 270ppm. I will be treating 30 litres of water.
270 x 30 = 8,100 mg of alkalinity.
8,100 x 0.00186 = 15ml Lactic Acid.



Dose the brewing liquor at the start, if you can, as it's easier. The alkalinity reduction will mostly take place in the mash tun, the same as phosphoric acid. Sulphuric and Hydrochloric reduction will take place in the HLT.

Hi Tom,

Great bit of work there and thanks for sharing, just wondering where you got 0.00186 from?? is this related to the concentration of the Lactic acid of is it a co-efficient you calculated??

Also Im not sure of the alkalinity of my water, can this be calculated from the bicarb or ph??

[DEMPSEY]

A TDS meter, total dissolved salts are cheap to buy and a salifert Caco3 fish tank test kit as well will give you what you need.

[DEMPSEY]

Total dissolved solids

[Tom]

Cheers Paul86, that is a really good question.

I don't remember exactly how I came by it, it's written in an Aisling copybook that has been misplaced. Something to do with MMols, chemical equations and atomic weights (belive it or not). There really was nothing online about using Lactic acid accurately in beer, just 'don't use more than xxx in 5 gallons'. I'll have a hunt for the book and show my workings when I find it. And I figured it out to the HBCs 80% lactic acid. If you get the 86% stuff, adjust accordingly.

Whilst looking for the above, though, I did rediscover my workings for how much Sodium, Potassium and Sulphates are contribuited to your beer when you use a campden tablet in your HLT.

And for my alkalinity I use the Salifert CaCO3 solution, but fish people call it KH. £9 off ebay.