Possible Clues:

• There's something about the wine that makes it go off
• Kind of card
• This tells you it's blown up, by the sound of it
• Noise - news
• Engineers left statement after investigation
• What is there about this sort of wine that makes it go pop?
• Narrative given by porter
• This might go off about the end of 8 down
• Account of a bang?
• Rumour about fortified wine