Talk Dirt to Me

As a child, I loved to play in the dirt. Mud pies were my specialty. I could not have imagined that all these years later I would be studying dirt (soil, actually) as part of my ongoing wine certifications.

Digging my hands deep into the cool, moist earth, I never thought much about the texture of soil (clay, silt, loam, sand, gravel) or its type (limestone, chalk, granite, slate, volcanic). And how could I have known that soil has a structure, a level of acidity, and a composition of nutrients and organic matter that is broken down by all those beetles, mites, and earthworms that so fascinated me in my youth?

What does this all have to do with wine? Well, soils are a central component of any discussion of terroir—the notion that wines can express the characteristics of the specific place where the grapes are grown.  In fact, the French Appellation d'Origine Contrôlée (AOC) system lays down a legal framework for naming wines after their geographic place of origin whereby boundaries are defined by soil type. Since other EU countries use this same classification model one might conclude that the idea of terroir is an accepted European concept.

Actually, Terroir is a hotly debated subject that until recently was greeted with a good deal of skepticism by new world wine producers. As author Jamie Goode has written, the skeptics believe soil and other climatic factors have little effect on a wine’s characteristics and that terroir is just a marketing ploy on the part of the Europeans.

As a wine professional I often use words like mineral, flint, smoke and slate to describe certain non-fruit flavors and aromas in a wine and there are certain wines that consistently display these characteristics. According to Goode, scientists agree that these flavors and aromas are not extracted from the soil.

But Goode also points to some ongoing research in plant physiology—specifically that certain genes involved in producing flavor compounds may very well be influenced by soil nutrients. This might give credence to the contention that not only do certain wines taste of  “somewhere” but that these flavors of dirt and minerals make them all the more interesting and delightful.

The debate continues. Sometimes it gets dirty.

Tags: wine | soil | Goode, Jamie,