Tartaric acid is a naturally occurring acid that is found in many fruits, including grapes. It is one of the main acids found in wine and plays an important role in the fermentation and aging process of wine.

During fermentation, yeast converts the sugars in grapes into alcohol and carbon dioxide. Tartaric acid is also converted into other acids, such as malic acid, by the yeasts. The acidity levels in wine are measured by the pH and the total acidity (TA) which is typically measured in terms of tartaric acid.

Tartaric acid gives wine a crisp, refreshing taste and helps to balance out the sweetness of the wine. It also helps to preserve the wine by making it less hospitable to spoilage microorganisms, which allows the wine to age properly.

Additionally, tartaric acid can also be used to adjust the acidity levels in wine during the winemaking process. Winemakers may add tartaric acid to the grape juice before fermentation to increase the acidity of the wine, or they may add it after fermentation to lower the acidity of the wine. This can be useful in regions where the grapes don’t have enough natural acidity or to adjust the acidity levels to a desired taste profile.

In short, tartaric acid is an important component of wine that plays a role in fermentation, aging and taste. It is used to adjust acidity levels in wine and help preserve the wine for aging.