Bubbly in cold picnic baskets (8)
I believe the answer is:
champers
'bubbly' is the definition.
(I've seen this before)
'cold picnic baskets' is the wordplay.
'cold' becomes 'c' (eg on taps).
'picnic baskets' becomes 'hampers'.
'c'+'hampers'='CHAMPERS'
'in' is the link.
(Other definitions for champers that I've seen before include "Bubbly" , "celebratory drink" , "something sparkling!" , "People who eat" , "Drink casually" .)