Having got the ale flowing, raised the subject of (8)
I believe the answer is:
broached
'raised the subject of' is the definition.
The answer and definition can be both to do with communicating as well as being past participle verbs.
Perhaps there's an association between them I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for broached that I've seen before include "Touched on" , "Raised for discussion" .)