Lactic Acid is used in beer brewing to lower the mash or sparge pH, this helps to reduce tannin extraction during the sparge keeping the sparge runoff below 5.8pH. it is also used to pre-acidify wort before adding Lactobacillus bacteria.
It has an 88% concentration.
Directions for use
To pre-acidify wort, add lactic acid directly to boiled wort at 1.5 – 2 mL/L. Use a pH meter to verify that the pH is between 4.5 – 4.8. Cool the wort down to 30 – 40°C before pitching in Lactobacillus bacteria.
To reduce alkalinity, prepare a normal solution (1 ml = 1 mEq) by diluting 84.7 mL of lactic acid to 1 litre. 1 ml of this solution reduces the alkalinity of water by 50 ppm as CaCO3(1 mEq/L).