Beer, so to speak (4)
I believe the answer is:
suds
'beer so to speak' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for suds that I've seen before include "Froth of soap and water" , "Lather" , "Soapy water" , "Foam from detergent" , "Lathery bubbles" .)