Some cream is sour in this state (8)
I believe the answer is:
missouri
'this state' is the definition.
(Missouri is an example)
'some cream is sour in' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'MISSOURI' is hidden in the letters of 'cream is sour in'.
(Other definitions for missouri that I've seen before include "US river - state" , "State of central US" , "24th American state to join the Union, 1821" , "Biggest tributary of the Mississippi" , "Midwestern US state" .)