Portuguese and Spanish, as well as (acido) Italian term for sour; see there.
One of the six taste sens ations (in addition to bitter, fatty, salty, sweet and umami) that is mainly perceived in the middle edge of the tongue. However, the acid sensation is relatively strongly dependent on the wine temperature. In warm conditions, the impression of sharpness is intensified by the interaction of alcohol and acidity. A dry white wine with a total acidity of 7 g/l appears very acid at a high temperature of 18 °Celsius, but pleasantly fresh at an optimal drinking temperature of 10 to a maximum of 12 °Celsius. The different acids in the wine cause different sensations. Lactic acid has only a slightly sour...
There is a vast number of sources on the web where one can acquire knowledge about wine. But none has the scope, timeliness and accuracy of the information in the encyclopaedia at wein.plus. I use it regularly and rely on it.
Sigi Hiss
freier Autor und Weinberater (Fine, Vinum u.a.), Bad Krozingen