Citric Acid

Used to adjust the pH level of the wort by adding acidity, primarily to achieve a desired tartness in certain beer styles, like Belgian witbier, or to compensate for naturally low acidity in a brew, particularly in low-alcohol or non-alcoholic beers; it can also be used to help sanitize equipment by lowering the pH level, making sanitizers more effective. 

• Flavor profile:
  Citric acid adds a subtle lemony tartness to the beer, which can be desirable in specific styles. 
  
• pH adjustment:
  The main purpose of adding citric acid is to lower the pH of the wort, which can impact yeast health and fermentation. 
  
• Application:
  It is typically added in small amounts during the mash or sparge stages of brewing to ensure even distribution. 
  
• Important consideration:
  Overuse of citric acid can result in an overly sour beer, so careful measurement is crucial.