What follows was originally posted by Wayne Young on 2/11/11 on his blog http://bastianichwinery.typepad.com/the_buzz/
Sauvignon needs to mature slowly for it to show good aromas and structure, and the soil of COF is adapted to bring out the best in Sauvignon.
The typical soil of the COF, known as “ponca” or “flysch” is a light –colored calcareous marl, formed deep beneath the sea, where water pressure compressed this calcium rich sediment.
The soil of COF is described as “cold”… its light color reflecting, rather than absorbing heat. This cool soil keeps the natural vigor of the vines in check, allowing them to ripen fruit slowly, allowing aroma compounds to develop and holding on to that brisk acidity.
Another unique quality of this type of soil is how it swells and shrinks when it gets wet and dries out. When the soil shrinks after swelling up with water, small cracks are formed in the soil that allows vine roots to burrow deep. The flat stones are unique and important for the drainage of excess water, but also because as the roots grow into the soil and encounter these flat rocks, the roots grow BETWEEN the flat surface and the soil, gripping onto the flat stone and picking up micronutrients from the rock.