d'Arenberg's love affair with Grenache reaches its pinnacle with Ironstone Pressings. The original block planted in 1918, on the lower side of the winery, has a plentiful amount of ironstone throughout the soil structures, which enhances the body and tannin structure of the wine. As the finished wine is a cepage of three grapes it is a matter of selecting and screening the very best Grenache barrels. They complement the Dead Arm Shiraz component which likewise complements the 28 Rd Mourvedre portion to a point where the Grenache is beautifully framed.

Most of McLaren Vale's soils are impregnated with ancient, decomposed laterite granite known as ironstone. The larger pieces were cleared from vineyards in the late 1880s and utilized in many of the buildings at d'Arenberg. Small batches of Shiraz, Grenache and Mourverdre are separately passed through a rubber toothed crusher into open fermenters. Some parcels are tread by foot two thirds of the way through. When tannin extraction is just right, the wines are basket pressed into oak for the completion of ferments and malolactic. Components are matured on lees in a combination of seasoned and new French oak barriques before assembling into the final wine.