Tavern ale could be thus: without a receptacle to put it in (6)
I believe the answer is:
barrel
'be thus without a receptacle to put it in' is the definition.
I can't judge whether this definition defines the answer.
'tavern ale' is the wordplay.
'tavern' becomes 'bar' (I've seen this before).
'ale' becomes 'rel' (I can't justify this - if you can you should believe this answer much more).
'bar'+'rel'='BARREL'
'could' acts as a link.
Can you help me to learn more?
(Other definitions for barrel that I've seen before include "Round wooden vessel." , "Round wooden cask made by cooper" , "Cask, drum" , "Cheerful old song: 'Roll out the . . . . . .'" , "Liquor container" .)