My beer keeping cold in boat (7)
I believe the answer is:
coracle
'boat' is the definition.
(I know that coracle is a type of boat)
'my beer keeping cold' is the wordplay.
'my' becomes 'cor' (both are expressions of surprise).
'beer' becomes 'ale' (type of beer).
'keeping' indicates putting letters inside.
'cold' becomes 'c' (eg on taps).
'ale' enclosing 'c' is 'acle'.
'cor'+'acle'='CORACLE'
'in' acts as a link.
(Other definitions for coracle that I've seen before include "Small rounded boat" , "craft" , "Small paddled boat" , "Welsh wickerwork boat" , "Traditional rounded boat with wicker frame" .)