Beer made by witch? (4)
I believe the answer is:
brew
'beer' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for brew that I've seen before include "Mixture" , "Concoction" , "Make (tea/coffee)" , "Ferment, concoct" , "Prepare by boiling and infusing" .)