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Lactic Acid

• Lactic acid, from the Latin word for milk - lactis (see more), is found in wine due to microbial attack on various substrates.
  
  The main source of lactic acid in wine is from the conversion of malic acid. to lactic acid during Malo-Lactic Fermentation (MLF).
  
  Smaller quantities of lactic acid can also be produced during fermentation by yeasts.
  
  
• Lactic acid is a softer acid than malic acid.
  
  
• Lactic acid is a stable acid but an expensive and weak acid, hence not the choice for acid additions.
  
  
• Lactic acid is a monoprotic acid (see diag.) and requires one molecules of NaOH to react with one molecule of lactic acid (see equation).
  
  
• Expected levels of lactic acid found in wine are 0.1-3.0g/L.