I couldn’t find my copy of Shut It (which has the episode reviews with "booze", "birds", "motors", "Doyle cooks a bit of pasta" and "slash fiction moment" subheadings). It’s in a pile somewhere. When I do stumble across it I’ll check & update this.
OK, lacking the book I did the next best thing & searched the transcripts for ‘scotch’ and ‘whisky’. These are all the episodes I could find where Cowley’s having a drink/offering a drink and there’s a visible bottle. Interestingly, most of them are in Season One:
Everest was also Conquered - @ 8 min - Glenfiddich
Female Factor - 19 min - 100 Pipers (yuck!!)
Annie - 11 min - Glenfiddich (Annie’s bottle)
When the Heat Cools Off - 33 mins - Glenfiddich
Klansman - 16 min - Glenfiddich
Rogue - hospital scene - Glenfiddich (broken bottle - thank you byslantedlight!)
In the Public Interest - this is an interesting one – there are 2 drinking scenes in Cowley’s flat, the first with Pellin at about 4:30, the second with the Minister at about 22:30. The bottle is completely unknown to me. Looks like C…(something)…N Mill from the first scene & I'm not sure if it's the same bottle from the back in the later scene or not. Anyone got a clue? Maybe it’s a made up brand, meant to look like something a bit special for home drinking?
Stopover - 17:50 min – the label’s covered up, the bottle is green, label yellow, white top. Doesn’t quite match either J&B or Cutty Sark, I assume it’s a blend, though.
Need to Know – 6:30 and 11:18 – a bit dark but looks like Glenfiddich again.
FWIW I like the Laphroaig too.