Appreciate case of red knocked back at home with family (5,2)

'appreciate' is the definition.

'case of red knocked back at home with family' is the wordplay.
'case of' says to hollow out the word (remove centre letters) (outsides of).
'knocked back' says the letters should be written backwards.
'at home' becomes 'in' ('in' can be similar in meaning to 'at home').
'with' is a charade indicator (letters next to each other).
'family' becomes 'kin' ('kin' can be a synonym of 'family').
'red' with its middle removed is 'rd'.
'rd' back-to-front is 'dr'.
'dr'+'in'+'kin'='DRINK IN'