Soil to Soil

Estate Blog

Soil to Soil

The Napa Valley was formed over time, through shifting of tectonic plates, volcanic activity and the flooding of the San Pablo Bay. This set of unique geological occurrences gave way to an amazing mix of soils that allow Napa to produce wines of remarkable quality. In this small Valley, we have half of the Earth’s soil types, over 100 soil variations and 33 soil series.

Soil Hands

The Mayacamas Mountain Range rises on the west side of the Napa Valley with rocky soil, and the Vaca Range in the east with sandstone and shale. Soils generally found on the Valley floor are deep and have good productivity. Alluvium, a mix of gravel, sand and silt, is one of the most famous soil types to produce Cabernet Sauvignon, and is found throughout Napa Valley. It is found in formations called alluvial fans—triangle-shaped deposits that form over time as water descends from the mountains. In Napa Valley’s case, river terrace, or underwater rivers, transferred alluvial and fluvial deposits onto the valley floor. Alluvial soil is so granular that gravity pulls water away from the vines. This forces the vine to chase the water source, taxing the plant, and thus producing a small concentrated grape. The Rutherford region is a famous example of an alluvial fan.

Soil Map

Our Sycamore and Bosché Vineyards are in the western benchland of Rutherford. In the Spring, the water table rises, providing nutrients for growth. In Summer, the water table falls, intensifying the fruit’s flavors. The soils are well-drained and deep, allowing for deep root systems. Wines produced from the Rutherford benchland have been described as “dusty”; some say you can taste the Rutherford dust.

“It takes Rutherford dust to grow great Cabernet.” – Andre Tchelistcheff