Lactic Acid is used in many Belgian beer styles to sour the beer. 

PLEASE NOTE: current best before is December 2021 (ignore date on photo image)

88% Lactic Acid 

Acid additions counter the H+ ion and directly lower the alkalinity of the mash.

Popular additions include phosphoric acid and lactic acid. All of these contribute other flavors and ions to the beer as well, which can again cause problems if used in excessive amounts. Lactic acid will add lactates. Sulfuric acid will contribute sulfates. In general you should add the minimum needed to achieve your target pH or the level of sourness desired. The amount will vary depending on the concentration of your acid and wort volume.

100ml amber bottles

best before 17/12/2021