Beer artisan brewed is a problem (11)
I believe the answer is:
brainteaser
'problem' is the definition.
'beer artisan brewed' is the wordplay.
'brewed' indicates an anagram.
'beer'+'artisan'='beerartisan'
'beerartisan' anagrammed gives 'BRAINTEASER'.
'is a' is the link.
(Other definitions for brainteaser that I've seen before include "difficult exercise" , "It might be difficult" , "Puzzle" , "Puzzling thing" .)