Tea is acidic, but the extent of the acidity depends on how long it is brewed for and the type of tea. The acidity of black tea lies around 4.9 on the pH scale.
A neutral pH level of can be found in pure water, however most food and drinks are at least slightly acidic. There are some alkaline herbal teas such as redbush, peppermint and ginger teas. Fruit juices have a pH level of 3 to 4 in acidity. Sodas and sports drinks have a pH level of 2 or 3.
The acidity of tea can be tasted through its sourness. The stronger the sourness of the tea, the more likely the acidity is to be higher. Many teas contain dominant anions, which are the acidic compounds, are found in tea. Examples include oxalates which can be found in vegetables and fruits, and citrates which are organic compounds found in citrus fruits. Citric acid is often added to teas to adapt the taste, and for those looking to avoid acidic drinks should avoid this addition.
Many teas, such as green and black tea, have very little effect on the tooth enamel and are comparable to water in effect. Green tea may also have oral health benefits due to its antioxidant catechins that are found in it.