The acid, also known as malic acid or hydroxy succinic acid, is next to tartaric acid and citric acid one of the three main organic ones acids in the Wine, In nature, it mainly comes in unripe apples, barberries, quinces, gooseberries, rowan berries and grapes in front. It got its name because it was first isolated and described from apple juice in 1785. In the still unripe grapes it has a high proportion up to 20 g / l, in wine the proportion is between 0.5 to 6 g / l. The must acids are removed in parallel to the storage of sugar during ripening of the berries.
Malic acid is breathed in between 20 to 30 ° C, that is burned as part of the cell metabolism and in sugar converted, while the tartaric acid is only broken down at higher temperatures. That is why the amount of tartaric acid remaining in ripe grapes is always higher. The tartaric acid is considered a soft, pleasant acid, the malic acid, however, as an aggressive tasting acid, which the wine edged and tastes hard.
The proportion of acids in the grape is both of the vine as depending on the weather conditions. The malic acid content is generally high in cool years with immature grapes, and low in sunny, warm years. So it is the high malic acid content due to imperfect maturity of the wines angry or makes it seem inharmonic. Malic acid is tolerated to a limited extent in white wines because it gives freshness to young wines. Early-ripening varieties, which ripen even at high late summer temperatures, have a taste-related acid deficit in autumn due to the temperature-related faster breakdown of the must acids, which is why they are mainly used for the production of grape juice or half-fermented musts be used. In red wines, malic acid is generally undesirable, so that over the malolactic fermentation (Biological acid degradation) the conversion to the milder lactic acid is carried out. See a list of all wine ingredients below total extract,