Willunga 100 takes its name from the historic Hundred of Willunga, an administrative land division established in 1839, just three years after South Australia was first settled, when a hundred households were required to occupy an area before it could officially be marked on the map. The winery has carried that local history into its own identity since releasing its first vintage in 2005, sourcing fruit from the McLaren Vale sub-districts of Blewitt Springs and Clarendon.

Grenache sits at the heart of the winery's focus, grown on old, low-yielding bush vines that Blewitt Springs' deep sandy soils are known for producing. Alongside that Grenache emphasis, the winery also works with Tempranillo and blends built around Cabernet and Shiraz, each reflecting the warm, Mediterranean-influenced climate that has made McLaren Vale one of Australia's most respected red wine regions.