The view from Monte Bello Ridge on Black Mountain forms a scenic backdrop that is relatively undiscovered in the San Francisco Bay Area. Here in the Santa Cruz Mountains, native oaks, redwoods, and madrones stud the deep and shady canyons that draw cyclists, hikers, and nature lovers alike. From the rich riparian habitat flows streams that trickle their way into the Bay. And hugging this natural landscape is Silicon Valley, the epicenter of technological innovation, which makes this entire area a distinctively unique global treasure. But the attraction for me is in harnessing the fiery timeline of geologic events that took place beneath my feet millions of years ago – events that inextricably connect the land to the wine at Ridge Vineyards – Monte Bello.
Ridge produces some of the world’s most coveted wines on a mountain which is primarily made of limestone, brought here via a tectonic journey originating from the tropical Pacific. Any ground material off this landmass is not composed of the same. Discerning wine drinkers know this and appreciate the special soils that contribute to Ridge’s site-specific, terroir-driven wines.
The idea of site-specificity in California was championed in great part by Paul Draper, longtime chief winemaker, now Chairman of the board of directors at Ridge. Vineyard-designated wines and minimal handling allows their wines to be “determined by the vineyard – by nature, not by man,” as it reads on its label. Ridge believes it is the only way to make great wines. What results are wines like Monte Bello, a classic example of a Bordeaux blend. These wines are lovely, distinctly delicious and characterful Cabernet Sauvignon-dominated blends that undergo an intense assemblage process to determine how much, if any, Petit Verdot, Merlot, and Cabernet Franc will be included in the finished wine. Opulent, but not overly big, Monte Bello wines are well-structured and balanced, have phenomenal acidity with layers of purity that showcase the terroir. They display persistence, elegance, a hallmark stony finish, and the potential to reveal the aha moment for many wine lovers.
For me, this defining moment came full circle during a recent visit while standing on the crush pad looking west into the nearby lush and verdant lowland rift valley.
“We are on the edge of North America,” says Eric Baugher, COO and winemaker of Ridge Monte Bello. Approximately 10 miles below this valley, the North American Plate and Pacific Plate come together to form the infamous geological sliding battle we know as the San Andreas Fault. I imagine it would be a breathtaking field trip amid the conifers and overgrown brush, which cover an assemblage of ancient oceanic crust material of sandstone, shale, and clay, known as Franciscan Complex, that have been churned and exposed over millions of years. This foundation, together with the climate, elevation, and proximity to the Pacific Ocean, make the Santa Cruz Mountains AVA a significant yet still best kept secret in the world of wine.
However, Ridge’s vines penetrate a subsoil of a slightly different kind – limestone, which is rare in California and somewhat of an anomaly in the Bay Area. This mountain on which we were standing was dragged by the ancient Farallon Plate, which laid between the converging North American and Pacific Plates.
“It hit North America, shaved off and left this mound right here,” says Baugher. The rest of the plate slipped under North America.
“We’re on super solid ground,” says Baugher, alluding to the fact that we are safe despite standing so close to the source of seismic activity. He assures me that this mountain didn’t budge much during the 6.9er of the 1989 Loma Prieta earthquake. Fortunately, only a few bottles succumbed to the rattle that devastated many parts of the Bay Area.
It’s curiously astonishing to think that it took over 120 million years of tectonic drift for this rock to travel from 6,000 miles away near present-day Indonesia to reach this point of North America and create the land that now generously lends itself to Ridge’s iconic wines.
Geologists call this crust that’s been formed elsewhere but traveled to current day landmass exotic terrane (different from terrain). And when we talk about limestone, we know that its formation always begins at sea as a limey ooze of calcareous algae and marine organisms that live, die, and accumulate in shallow marine shelves. But contrary to limestone formed from a coral reef, the limestone at Ridge was formed from a sea vent from an oceanic volcano. “Superheated water just precipitated calcium carbonate in the ocean to form this mass,” he says.
And so Baugher, a biochemistry and molecular biology major from University of California, Santa Cruz, who was destined for a career wearing scrubs and a white coat, took a summer job as a chemist at Ridge in 1994. The following year, Draper passed along more responsibilities to Baugher with the management of production and winemaking.
Consistent to Draper’s vision, Baugher and the Ridge team are custodians of the land, paying meticulous attention to every vine because minimal intervention actually takes a focused effort. Great emphasis is in the vineyards to draw out the purest expression of each vineyard block, but having said that, the winery also experiments with techniques to improve quality.
“Just the Bordeaux varieties alone, have 45 vineyard blocks,” he says. “It could be absolutely crazy in some vintages – everything we do in the vineyard and the winery, breaking down the vineyard and fermenting in small batches… but then the more you split it, the more options you have later on for blending.”
Careful selection and assemblage is how Ridge develops Monte Bello, but not without respecting the ground from which the vines’ roots drive deep within.
“Terroir is a very complicated thing, but I think the geology, the mineral composition of the soil has the most impact on the wines I make.”
While the key subsoil is calcareous, the overlying topsoil is an ancient seabed mixed with friable, iron-rich sedimentary rock.
“In areas where the topsoil has eroded or accumulated, the location of limestone can be shallow or deep. This has an influence on the wine’s display of acid and minerality,” he says.
Baugher attributes other unique characteristics to the distinctive mountain wines of Monte Bello. Elevation is certainly on their side, where the growing areas range between 1,300 to 2,700 feet. Their close proximity to the San Francisco Bay and Pacific Ocean makes for one of the world’s most unique terroirs. Cool climate lends character and firm acidity to the Monte Bello wines, and limestone translates to added complexity and a consistent streak of minerality.
Winemakers have coveted limestone for its unique properties that impart that desirable structure in wine. Indeed it is found in many famous places, such as Champagne, Burgundy, Bordeaux, Barolo, Tuscany, Jerez, and Dalmatian Coast.
The benefits are many. First, it has incredible water-holding capacity. This allows Ridge to dry farm. When the vines need water, their remarkable roots penetrate deep into the source as needed. Simultaneously, limestone provides excellent drainage.
“The fractures in the rock give it a porosity to soak in winter rain and hold it,” says Baugher. Dry farming coaxes the vines’ roots to go deep and draw from that water resource. “
Calcium-rich limestone soils also tend to have a higher pH than other soils. Being more alkaline, it generally translates to easier nutrient absorption and encourages grape production with a relatively high acidity level.
“Acidity is one of the unique characteristics of Monte Bello,” says Baugher. “It allows the wine to age slowly and maintain great flavors over many decades in the bottle. In addition to freshness and lively acid, there is a great mineral flavor that comes in the aftertaste. That is usually where I can recognize Monte Bello’s limestone, it’s like imagining tasting crushed rock and flint.”
As we walk toward the cellar to have a taste, a handsome piece of limestone appears out of the corner of my eye. The terroir collector in me wants to ask if I can take it home. “Take it, of course,” says Baugher. Excitedly, I examine the specimen. It’s heavy. One side displays a matrix of fossilized marine life. The other side is partially crystallized, showing evidence that this rock, borne of the Mesozoic Era, had endured heat and pressure to get to this place … “to make wine!” I said. We laughed as I quietly realized that this is the connection I’d hope that wine lovers would be able to make when they drink Ridge Monte Bello wines. This geological artifact comes with the responsibility to ensure that the rock would not only be the “show” of my “tell” when I describe Ridge’s unique terroir – 126 million years in the making – but that it would spark inspiration in others, just as wine’s connection to the land inspires me. Rocks can do this. And a rock of this magnitude (seismic pun intended) makes it all the more delicious.
USGS Rocks in the San Francisco Bay Region #2195 https://pubs.usgs.gov/bul/2195/b2195.pdf
Scholz, C. H.: The Black Mountain asperity; seismic hazard of the southern San Francisco Peninsula, California, Oct. 1985. (GEOPHYSICAL RESEARCH LETTERS; Vol. 12, No. 10, p. 717-719.)
Franciscan Complex Calera limestones: accreted remnants of Farallon Plate oceanic plateaus: Tarduno, John A.; McWilliams, Michael; Debiche, Michel G.; Sliter, William V.; Blake, M. C.