"turn sour" in German to turn sour kippen umschlagen säuern Detailed translations for "turn sour" to turn sour 1. gastronomy to turn sour(also: to turn, to go off) kippen to turn sour(also: to turn, to go off) umschlagen{intransitive verb} 2. other to turn sour(also: to go sour) säuern{intransitive verb}