Tutties Neuk!

Great day out with ex-colleague Margaret with lunch at Tutties Neuk in Arbroath.  Their wall decorations are very attractive and this one was above our table.  Catch-ups are always fun and full of revelations and laughter.  The restaurant was selling gifts called "Cauld doubs"  -  a small bottle of fizzy wine with a large wine glass. The waitress couldn't tell us what a 'doub' was, but thought it must mean 'glass'.  Anyone know what it means?