Problem brewing artisan beer (11)
I believe the answer is:
brainteaser
'problem' is the definition.
'brewing artisan beer' is the wordplay.
'brewing' indicates anagramming the letters.
'artisan'+'beer'='artisanbeer'
'artisanbeer' anagrammed gives 'BRAINTEASER'.
(Other definitions for brainteaser that I've seen before include "difficult exercise" , "Puzzling thing" , "Puzzle" , "It might be difficult" .)