As I was walking through the vineyards, fixing the irrigation and trellising the new growth, I noticed the rich, black earth that the vines were growing in. Soil composition dramatically impacts the finished wine and is a key reason that only certain regions are suited to growing wine grapes, which have very different needs than many crops. Most farmers would be envious of a land owner whose soil is nutrient-rich and fertile. Yet farmers that cultivate the land for the production of wine grapes know that quality wines are produced by the vine's struggle to create the seeds it needs to reproduce. If the vines are too well accommodated they will instead produce grapes that are large and have less flavor, appropriate for the table but not for the bottle. It is crucial for the soil to retain water adequately but also be extremely well drained. It is helpful if the topsoil can retain and reflect heat, aiding the ripening process. Most grapevines do well with a pH between 5 to 6 but some varietals do well in more balanced soils from about 6 to 8. Calcium, iron and magnesium are minerals that are essential to the life of the vine, as well as nitrogen, phosphorus and potassium which are requisite to most plant life. However, grapevines are a remarkably tolerant and robust plant and can flourish in many different types of soils. Deerfield's vineyards, like much of Sonoma County, are composed of recent volcanic soil. The trace elements that the plant absorbs through its roots can dramatically impact the flavor of the grapes, although the idea that a wine contains the flavors of the minerals is somewhat of a myth. The famed wines produced from the slate soils of Germany's Mosel Valley are often described as possessing mineral flavors, but while soils can be accurately attributed to creating flavors ubiquitous to a specific terrior it is somewhat more difficult to pin down what exactly slate smells like. The field of soil science is one of the most extensively studied aspects of viticulture at oenological institutions around the world. But there is far more to a perfect bunch of Pinot Noir grapes than just the soil that the vines roots live in. Next time I'll describe the elements that make up terroir.