This acid lowers pH a bit less than Tartaric acid and is less sour. Malic acid is the primary acid of fruits such as: apples, peaches, plums, cherries and is present in most all fruits. It is typically considered the secondary acid of grapes. Increasing the proportional level of Malic acid in a wine tends to bring out an green apple tartness that can work well with certain white wines such a Sauvignon Blanc or Chablis. One teaspoon of Malic Acid will raise the tritratable acid in a gallon of wine by .15 per cent tartari. You do not want to add malic acid to any wine that will undergo a malolactic fermentation, as roughly half of the added malic acid will not convert to lactic acid during a malolactic fermentation.