I will say it again. It is not bottle, or whatever you call it, that Murray lacks. He just doe not have the skills to win a big time tournament. He CAN beat Nadal, Federer or Djokovic from time to time, but all these three, and even Ferrer and Del Potro, are much more talented than him.
I'm not sure its talent you know. The experts in the game all say Murray has the skills to win a major: he has a great backhand, a great change of pace on the forehand, good hands, good court coverage, and now a decent serve (which deserted him today obviously).
What he lacks is aggression, he doesn't seem to be able to impose himself on finals. He seems to wait for his opponent to implode and so far, when you are playing great players in a major final- they don't.
He seems to play within his own abilities in these finals, slicing and under-hitting the ball in dangerous areas but not really forcing the play or finding a dominant pattern. Djokovic just picked him off today with tremendous hitting. Murray was waiting around in rallies and invariably Novak won the long rallies too.
If I was Murray, I'd get Andre Agassi and Brad Gilbert in as coaches - because the Scot is a better player than some older players in history who have actually won Grand Slams. Still his body language and on court demeanour is a disaster though.