Tartness

Tartness is a sensory attribute describing a sharp, puckering taste often associated with acids present in foods and drinks. It is commonly grouped with the basic tastes of sweetness, sourness, bitterness, saltiness, and umami as a perceptible quality that signals acidity. In everyday language, tartness is used to describe citrus fruits, sour flavors, and beverages such as lemonade or sour beers, and may also refer to an overall impression of acidity even when sweetness or bitterness are present.

The perception of tartness is primarily linked to hydrogen ions released by acids in the mouth. The sour/tart sensation is thought to arise from proton activity affecting taste receptor cells, with multiple mechanisms implicated in humans. Quantitatively, tartness is often discussed in terms of pH (a measure of hydrogen ion concentration) and titratable acidity (TA), which estimates total acidity by neutralizing acids with a base. Different acids common in foods—citric, malic, acetic, and lactic acids—contribute characteristic flavors and intensities, and the overall tartness is influenced by sugar, salt, aroma, and temperature.

In culinary contexts, tartness is used to balance sweetness and fat, sharpen fruit flavors, and provide freshness in sauces, dressings, and beverages. In wine, tartness and perceived acidity influence freshness and aging potential. Cultural preferences for tartness vary, and the term can carry positive or negative connotations depending on the dish and regional tastes.