In Paris, a period to drink drop of Cognac 28 from bars (6)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

clue uses the solution to 28ac … In Paris, a period to drink drop of Cognac for free from bars definition is the underlined “ free from bars “, with the ‘ for ‘ from 28ac used as a link between the wordplay and the definition parts of the clue UN=”a” in French/”In Paris” + AGE=”period”; both around/drinking C, a drop (last letter? first letter?) of Cognac