souring

Noun

 * 1) The process by which something is made, or becomes, sour; acidification.
 * 2) The process by which fabric is soured, washing out the lime by means of acid.
 * 3)  Any sour apple.
 * 4)  Vinegar.

Translations

 * German: Säuern, Aussäuern, Säuerung, Aussäuerung, Versäuerung, Ansäuerung, Versauerung