GSM stands for Grenache/Syrah/Mourvedre so this is really an Australian version of Chateauneuf du Pape. In this case, it's 55% Grenache, 33% Shiraz and 12% Mourvedre which is not all that different from Chateau Beaucastel (30/20/30) or Clos des Papes (65/10/20). The Hewitson Miss Harry GSM also comes from 80+ year old vineyards and, like most Chateauneuf du Papes, is matured in old, rather than new oak barrels. Yet there is still a world of difference.
The color is several shades darker than a typical Chateauneuf of the same age, and big, bold tannins are much more apparent both in the aroma and the palate feel. The ripe cherry smells and flavors you expect from Grenache are here to lighten things up, but they are mostly covered by a thick layer of tannin. I like this wine, but I definitely want to put it in the cellar for at least a few years to soften the tannins.
At about $18 a bottle, it's a decent value compared to most Chateauneuf du Pape or Gigondas wines. But I still prefer my Southern Rhone favorites.