Before founding John Duval Wines in 2003, John Duval was chief winemaker at Penfolds. One of the select few to make Penfolds Grange, he followed in the footsteps of winemaking greats Max Schubert and Don Ditter.

John Duval Wines produces mainly red wines from a selection of old, low yielding Barossa vineyards at Marananga, Ebenezer, Krondorf and in the Eden Valley. Indeed a number are grape growers previously tapped for Grange. While the focus of John Duval Wines is old vine Shiraz, Rhône Valley varieties other than Shiraz are increasingly playing a role, particularly Grenache but also Mourvèdre, Marsanne, Roussanne and Viognier.

For John Duval Penfolds has been the springboard to his own label. The old vine Eligo Shiraz and Integro Cabernet Shiraz sit at the top of the John Duval label. The Plexus comes in both red and white blends.