葡萄酒中的酸是葡萄酒酿制中需要考虑到的重要成份之一。存在于葡萄和葡萄酒中的酸会影响到葡萄酒的色泽、口感，此外还有助于发酵并可以防止葡萄酒受细菌污染。大部分葡萄酒的pH值在2.9至3.9之间。一般来讲，pH值越低，葡萄酒越酸。然而葡萄酒的总酸度和pH值之间并没有必然的联系，亦即存在高pH值且高酸度的葡萄酒。

葡萄中主要有三种酸，即酒石酸、苹果酸和柠檬酸。在葡萄酒酿制过程中，起主要作用的酸是醋酸、酪酸、乳酸和琥珀酸。有些时候酿制葡萄酒也会加入额外的酸，例如抗坏血酸、山梨酸和亚硫酸等。

The acids in wine are an important component in both winemaking and the finished product of wine. They are present in both grapes and wine, having direct influences on the color, balance and taste of the wine as well as the growth and vitality of yeast during fermentation and protecting the wine from bacteria. The measure of the amount of acidity in wine is known as the “titratable acidity” or “total acidity”, which refers to the test that yields the total of all acids present, while strength of acidity is measured according to pH, with most wines having a pH between 2.9 and 3.9. Generally, the lower the pH, the higher the acidity in the wine. However, there is no direct connection between total acidity and pH (it is possible to find wines with a high pH for wine and high acidity). In wine tasting, the term “acidity” refers to the fresh, tart and sour attributes of the wine which are evaluated in relation to how well the acidity balances out the sweetness and bitter components of the wine such as tannins. Three primary acids are found in wine grapes: tartaric, malic and citric acids. During the course of winemaking and in the finished wines, acetic, butyric, lactic and succinic acids can play significant roles. Most of the acids involved with wine are fixed acids with the notable exception of acetic acid, mostly found in vinegar, which is volatile and can contribute to the wine fault known as volatile acidity. Sometimes, additional acids, such as ascorbic, sorbic and sulfurous acids, are used in winemaking.