I recently saw the following on another brew site:
http://www.probrewer.com/vbulletin/archive/index.php/t-6245.html
"The generally held information for reduction of pH by Lactic acid is 58 grams of 100% Lactic (Rarely you will find it 100% - more typically it is 85% so adjust accordingly) per 100 Kg malt to reduce pH by 0.1 in Mash and 29 grams in the Kettle. Other information is given in Stephen Holle's (MBAA) book 'Handbook of Basic Brewing Calculations'. "
By my calculations using the above I came up with the following for homebrewer volumes:
At 88% solution need .09036 gm lactiic acid per lb of grain to drop pH by 0.1.
I tried this a week ago with a Belgian Golden Strong and following these calculations it did reduce the mash pH from 5.5 to 5.4 in a couple of minutes time.
I recently purchased a used copy of Stephen Holle's (MBAA) book "
Handbook of Basic Brewing Calculations" for $20. When it arrives I will see what additional information is included on this subject and pass it on.
There is an argument
against using
phosphoric acid, BTW:
1. Palmer (
How to Brew, p. 164) says, "Phosphoric acid is not recommended, because it reacts chemically with calcium in the mash and changes the whole playing field, rather than simply adjusting the pH."
Regarding flavor effect,
2. DeClerck (
Textbook of Brewing, vol. 1, p. 328) says, "The following acids are used for acidification: sulfuric acid, which gives beer a dry palate, or hydrocloric or lactic acids which give beers with fuller palates." The above is quoted without attribution virtually verbatim in Goldammer (
The Brewer'sHandbook, p. 158) and
The Practical Brewer, p. 118 (1977 ed).
Fix (
Principles of Brewing Science, p. 11) has a chart comparing acid treatment of water using lactic, phosphoric and sulfuric acid. He offers specific amounts for each based upon the alkalinity of the base liquor and moving to a pH of either 5.5, 6.0 or 6.5. Using 6.0 as your target, and
50% lactic acid (only amount listed), Fix recommends at 100 aalkalinity 22 g/Hl; at 200 alkalinity 50 g/Hl, and at 300 alkalinity 73 g/Hl.
Hardwick (
Handbook of Brewing, p. 148) suggests 72 g p/100 kg of malt if using 80% lactic acid, to change the pH by 0.1.
Hope this helps.
Mark
Hidden Well Brewery (site below)
http://www.makewebs.com