Shiraz

[Farmalance]

Hi again
I am manfully drinking my way through copious amounts of red wine in an attempt to distinguish on from another. It's a bugger of a task, but I'm sticking to it.
Tonight I had a crack at a bottle of Jacobs Creek Grenache Shiraz 2003. Does the Grenache have a significance? It also had a very light 'fizz' to the tongue - is that the nature of the Shiraz?
I have also figured that the 'heavier' reds are the Burgandys moving through the Cab Sav towards Pinot Noir and onto the lighter Shiraz and Merlot. Am I on the right line or is my mission interfering with my judgement???
Cheers
Lance