1.   After a time, all knew that the concourse was not going to turn sour or break up in a fight.

2.   As time went by, their Marriage turned sour.

3.   At this point, the award ceremony threatens to turn sour.

4.   Milk turns sour very quickly in hot weather.

5.   Some have actually instituted casual dress on snowy days so that workers can dress comfortably and warmly when the weather turns sour.

6.   The vision of bedsit freedom would soon turn sour.

7.   Their friendship was beginning to turn sour.

8.   Those risks can turn sour, as they do for any pin-striped Market-maker.

9.   When the company began to lose money, things turned sour between the directors.

10.   When the Market turned sour on the wireless newcomers, the big bidders were stuck.