Brewer leaves brewery with direction for what goes in beer (5)
I believe the answer is:
yeast
'in beer' is the definition.
(I know that beer has part or parts the yeast)
'brewer leaves brewery with direction' is the wordplay.
'leaves' is a deletion indicator.
'with' is a charade indicator (letters next to each other).
'direction' becomes 'east' (compass direction).
'brewery' with 'brewer' taken away is 'y'.
'y'+'east'='YEAST'
'for what goes' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for yeast that I've seen before include "Dough raising agent" , "Fungus used in brewing and baking" , "It makes dough rise" , "Brewing agent" , "Androgynous" .)