The acid, also called malic acid or malic acid, is in addition tartaric acid and citric acid one of the three main organic acids in the Wine, In nature, it mainly comes in unripe apples, barberries, quinces, gooseberries, rowanberries and grapes in front. It got its name because it was first isolated and described in 1785 from apple juice. In the still immature grapes, it has a high content up to 20 g / l, in wine, the proportion is between 0.5 to 6 g / l. Parallel to the sugar storage during berry ripening, the must acids are removed.
Malic acid is breathed between 20 to 30 ° C, that is burned as part of the cell metabolism and in sugar converted, while the degradation of tartaric acid takes place only at higher temperatures. Therefore, the remaining proportion of tartaric acid in ripe grapes is always higher. Tartaric acid is considered to be a soft, pleasant acid, while malic acid is a more aggressive tasting acid, which is the wine edged and hard to taste.
The proportion of acids in the grape is both of the vine depending on the weather conditions. In cool years with unripe grapes, the proportion of malic acid is generally high and low in sunny, warm years. So it is the high malic acid content due to imperfect maturity, the wines angry or inharmonious. In white wines, malic acid is tolerated to a limited extent because it gives freshness to young wines. Early ripening, still maturing at high late summer temperatures have a taste acid deficiency in the fall due to the temperature-induced faster degradation of the must acids, which is why they mainly for the production of grape juice or semi-fermented musts be used. In red wines, malic acid is generally undesirable, so over the malolactic fermentation (Biolgarian acid removal) the transformation into the milder lactic acid is carried out. See a list of all wine ingredients below total extract,