Hello friends,

Bob here with some soil talk. While Kelly, Melissa, and Maggie handle all things Fall wine club release and Dallas, Jesse, and the cellar team are knee-deep in an early harvest, I’m thinking about…you guessed it…soil!

The next time you visit Alta Colina, you can see something that normally remains completely hidden: a five-foot-tall slice of the Vineyard, removed intact from the ground and mounted in our Tasting Room.

It came from Block 11, our 22-year-old Mourvèdre block. When you taste wine grown there (Sun Worshipper), this is the underground landscape those vines have been living in.

This spring, we dug two trenches between adjacent vine rows and carefully isolated a column of soil between two vines. The column was boxed, wrapped, lifted by an excavator, and sent to Sonoma, where it went through a months-long process of stabilization and mounting.

The finished monolith is about two inches thick, five feet tall, and weighs close to 100 pounds. Melissa is standing beside it in the photograph to give you some sense of scale.

What surprised me most was how dramatically the soil changes as you move downward.

In the top foot, the soil is dark and filled with a dense web of hair-like roots from both the vines and the cover crop. On close inspection, the soil is made up of tiny aggregates, small clods that leave spaces for water and air. A 2025 analysis measured 8.5% soil organic matter in this area, which is exceptional for a vineyard soil. For reference, most conventional cropland soils average 2.7% to 3.4% organic matter, and even well-managed pastureland, typically the highest of the bunch, tops out around 4.5%. We’re sitting at nearly double that top number per SARE’s soil research.

This dark upper layer is the result of decades of plants growing, dying, regrowing, and feeding soil life. Living roots, root exudates, decaying plant material, and microbial activity have all contributed carbon to the soil. Continuous cover cropping on this land for at least 60 years (according to previous owners), without a single pass of a tiller, has helped create what now looks almost like dark chocolate.

My ambition is to encourage that living, aggregated soil to develop farther down the profile.

Below about 14 to 18 inches, the color becomes lighter and the concentration of rock increases sharply. The jungle of fine roots begins to thin, although larger vine roots remain clearly visible.

At about three feet, the profile begins to resemble a pile of compressed rock. Yet it is not solid. There are still spaces between the stones, and the vine roots continue to find their way through them. One root nearly a quarter inch in diameter is visible at roughly four feet.

Those deep roots help explain how the vines continue to find water late in the growing season, long after the surface has dried. What happens below five feet remains unknown. We stopped digging there, but the rock (and probably the roots) appeared to continue downward.

That mystery may be my favorite part of the whole project. Even after removing a five-foot section of the Vineyard, we still did not reach the bottom of the story.

When you next visit, stand before the monolith and follow those roots down through the dark soil and fractured rock. Then taste Sun Worshipper and consider the journey in reverse: water and minerals drawn from the depths, lifted into the vine, transformed by sunlight, and gathered at last in your glass. And remember how much of a vineyard lives beyond our sight.