The first of our vineyards is our Cellar Vineyard, the vines which form the beautiful sweep of green immediately to the south of our Cellar Door.
The soil here is ‘Biscay Clay’, also referred to as ‘self-mulching black cracking clays’. These soils are relatively widespread in the McLaren Vale/Willunga strip and have unique properties. Slow to wet, they can hold a large volume of water, but hold it very tightly. Vines struggle to recover that moisture when it is needed, and so stress very quickly if exposed to a sudden heat-wave. The fruit therefore needs to be watched very carefully as it ripens, or it can very quickly shrivel and show sunburn.
When dry, these soils get cracks 2-3cm across, which can extend down as far as a metre. As they crack and separate, vine roots, irrigation pipes and concrete footings can all suffer, torn apart by the intense but very slow-moving force of the particles contracting after swelling when wet. It’s lousy soil to build houses on—which as farming land comes under pressure from urban sprawl, we think is wonderful—but vines love it, particularly Shiraz. Such vines can produce fruit with great fragrance and power and a structure which guarantees ageing potential.