Sour is used after these nouns:
whisky

Sour is used with these nouns as the subject:
relation

Sour is used with these nouns as the object:
atmosphere, relation

be, smell, taste
The sauce tasted very sour.
The milk smelled sour.

go, turn (both also figurative)
By the next day the wine had turned sour.
Their relationship quickly turned sour.

extremely, fairly, very, etc.
a little, slightly, etc.
Their friendship has turned a little sour.

leave a sour taste in sb's mouth (figurative)
The whole experience has really left a sour taste in my mouth.

Sour is used with these nouns:
apple, cherry, cream, disposition, flavour, milk, mood, note, orange, smell, taste, wine