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.