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Tartaric Acid

• One of the abbreviations for Tartaric acid is H₂TA.
  
  
• Tartaric acid, while abundant in grapes, is relatively rare in other fruits.
  
  
• Tartaric acid, within the grape berry, is biologically stable, while malic acid is not.
  
  
• Tartaric acid is practically resistant to microbial attack in grape juice or wine and hence often chosen as the acid for addition.
  
  
• Tartaric acid is a stonger acid than malic acid and hence the choice for addition to reduce grape juice and wine pH values.
  
  
• Tartaric acid is a diprotic acid (see diag.) and requires two molecules of NaOH to react with one molecule of tartaric acid (see equation).
  
  
• Tartaric acid will form potassium bitartrate (KHTa) crystal precipitates (deposits) in an unstable wine. (i.e. a wine supersaturated with respect to KHTa).
  
  The addition of tartaric acid to a stable wine, with respect to KHTa, will render that wine less stable.
  
  
• Expected levels of Tartaric acid found in wine are 1.5-4.0 g/L.