History of wine - Composition of wine and must (3)
Potassium tartrate (cream of tartar) is one of the most common precipitates at the bottom of some wine bottles, it is completely harmless. Wine can be preserved using acids. In wines that require aging, a certain amount of acid is naturally present.
Because acids naturally accentuate the other flavors of wine in the mouth, it is common for fruit to become more concentrated as the ripening process slows down. Malic acid is one of those that acts to slow down the ripening of fruit, especially during the warm season of the year.
It is a characteristic of the grape that is linked to the harvest season. Tartaric acid is another acidic variable in grapes, which is generally formed from tartaric acid. The concentration of tartaric acid is generally higher in Vitis vinifera (and in the tamarind fruit).
During fermentation, yeasts produce acetic acid in small quantities (less than 300 mg/liter) and its concentration enhances aromas and the complexity of flavors, giving rise to “complexity”. Acetic acid causes the synthesis of acetate esters, which give rise to fruity aromas.
Because of acetic acid, many types of bacteria cannot survive in low pH environments. It tastes sour and salty. Lactic acid is present in wine due to fermentation, although it has a mixed salty/bitter taste.
Malolactic fermentation produces lactic acid in small quantities, unless folic acid is consumed (which causes an increase in the overall pH of the wine).