The fermentation that takes place after the original fermentation has converted grape juice into wine. There are two types of secondary fermentation: malolactic fermentation, in which malic acid is converted into a softer lactic acid, and the second fermentation that takes place in tank or bottle during the production of sparkling wine and Champagne. For a more detailed explanation of each type of secondary fermentation, see malolactic fermentation and m├ęthode champenoise.