Our Approach

We approach vineyard analysis from a different direction than most traditional methods and our reports have different emphasis. Our goal is to provide a three dimensional understanding of the origin and history of vineyard substrate--what the material is, where it came from, how it got there, and how it varies vertically and laterally throughout a property. The visual and conceptual framework that results provides a fresh and integrated context for the diverse array of other data that is available.

Where winegrowers see sand, mud, and gravel, and soil scientists describe soil types, geologists see granular materials--sediments--that have a history and tell a story. These materials form from the weathering of bedrock, accumulate in place or are moved by water, wind, ice, and gravity, and form deposits that contain clues to their origin and spatial variation. Reading these clues allows us to map the distribution of different types of vineyard substrate and build a story of its formation.

In this era of advanced technology--including various methods of indirect sensing--our approach might seem primitive, but we believe that nothing fully replaces direct visual and tactile contact with vineyard sediments. Our analysis is based on direct observation, of vineyard topography, surface materials, vine condition, and backhoe pits. Each component provides information on substrate distribution and variation. Where useful, we make detailed maps of surface sediment texture and color, the first clue to what lies beneath the surface. Then we dig backhoe pits--distributed as densely as needed to reveal the details of subsurface variation--photograph them, describe what we see, and sample each layer of sediment for future analysis if so warranted.

Soil studies commonly focus on just a portion of the sediment--the sand silt and clay--considering coarser material such as gravel, boulders and cobbles to be adjunct materials of less importance. This leads to descriptions such as "sandy clay loam, 80 percent gravel." Such studies focus on description, providing information important to viticulture but no explanatory framework that provides understanding of intra-vineyard variation. Our geology-based work provides such a framework, one that can incorporate information from other approaches and disciplines.

From the moment we step onto a vineyard property, we begin to observe and piece together a story of the origin of that piece of land. As the work progresses we construct an increasingly detailed visualization of the vineyard and its history. By the end of the field phase, we carry with us a mental image of the vineyard and how it varies, in depth (vertically) and laterally. Our first step in producing a report is to combine pit photographs and descriptions, one for each backhoe pit. By questioning how each of these documents supports or modifies the larger picture, that model becomes progressively clearer and more detailed.

In a few years, we might well be able to connect mind directly with computer and transmit a hologram of this mental image to a client, discussing the interpretation as the image hovers in the air before each of us. Until then, we resort to words and pictures to convey as clear a version as possible of the three dimensional picture that we build. Our goal is for the client to internalize the model and use it as a context for all other vineyard data. One of the most vivid and useful products is a summary map of vineyard geology.

While the conceptual framework is the most valuable, long term, product of our work (an asset for future generations), the geological perspective has proven to have significant pragmatic use as well. It has been used in choosing rootstocks and clones for planting or replanting vineyards; for the design of vineyard drainage; and for the redesign of irrigation systems. In each case, the geologic studies revealed information not previously shown by other types of vineyard analysis.

In some cases, we have established direct correlation between areas of a vineyard that we can define geologically and either winemaker's taste or aspects of vineyard management. These correlations indicate that some factor reflected in the geology is also reflected in the vines and grapes. We do not yet know what the specific correlation is, though it appears to be related to drainage and/or the ways in which water becomes accessible to vine roots. It might be related to soil microbiology or the availability of trace elements. Whatever the correlation might be, its existence indicates the usefulness of a geologic perspective.

To date, most of our work has been in Napa and Sonoma. Our clients include Stag's Leap Wine Cellars, Etude, Araujo Estate, Harlan Estate, Bond, Napa Valley Reserve, Vineyard 29 and Aida, and Rudd Wines. In 2006, we will begin a project in northern Spain at Vinedo Senorio de Arinzano, an extraordinary property of nearly 1000 acres with several hundred planted to a variety of mainly red grapes.