Gold cask for beer contains malt initially for season (6)
I believe the answer is:
autumn
'season' is the definition.
(autumn is a season)
'gold cask for beer contains malt initially' is the wordplay.
I cannot quite see how this works, but
'gold' could be 'au' (Au is the chemical symbol for gold) and 'au' is found within the answer.
This may be the basis of clue (or it may be nonsense).
'for' acts as a link.
Can you help me to learn more?
(Other definitions for autumn that I've seen before include "1 Season of mists and mellow fruitfulness" , "Subject of 11 [ODE]" , "Fall (over the pond?)" , "American call it the fall" , "part of year?" .)