The very best ale I'd brew (5)
I believe the answer is:
ideal
'the very best' is the definition.
(I've seen this in another clue)
'ale i'd brew' is the wordplay.
'brew' indicates anagramming the letters.
'ale'+'id'='aleid'
'aleid' anagrammed gives 'IDEAL'.
(Other definitions for ideal that I've seen before include "An - - Husband (Wilde)" , "immaculate" , "Perfectly suited" , "that can't be bettered?" , "Textbook" .)