Jug used in brewery (4)
I believe the answer is:
ewer
'jug' is the definition.
(I've seen this before)
'in brewery' is the wordplay.
'in' indicates the answer is hidden within the clue.
'EWER' is hidden within 'brewery'.
'used' is the link.
(Other definitions for ewer that I've seen before include "Water-jar" , "from which liquid may be poured" , "Large water-jug" , "Large, wide-mouthed jug" , "Were (anag)" .)