A tour of California: its terroir and wine
3 MINUTE READ
Mention California and what images come to mind? Likely sunny beaches, Hollywood glamour, charming small towns, rolling vineyards, surfer dudes and Silicon Valley: think Tinseltown, Santa Barbara, Chateau Montelena Winery, the Beach Boys and iPhones. Wait, Chateau Montelena? Well, yes. That’s the winery that put California on the wine map when its 1973 Chardonnay won the Paris Tasting of 1976 (Check out the movie Bottle Shock if you want a version of the story). Since then, Napa Valley, Paso Robles, the Santa Ynez Valley and many other California locales have become legend in the wine world.
California climate, minerals and geography
How did an upstart industry come to worldwide prominence? A variety of factors, but high on the list is “terroir”. This French term is intended to capture how a particular region’s climate, soils and aspect affect the taste of wine. And California has wonderful terroir, in large part because of its geology. To explain:
The Mediterranean climate, with a long growing season with warm days and cool nights, is ideal for grapevines. The sun shines all day year-round, while critical water capacity is provided by a mix of rainfall, humidity and soil water-retention.
The diverse soils, resulting from weathering of a varied bedrock mineralogy, yield grapes that provide wines with unique flavour profiles. This is one of the factors that makes California wines so special and interesting.
The aspect (terrain) creates a range of microclimates, which allows growers to produce a wide variety of wines. California terrain has been created as three tectonic plates have collided and dramatically shaped the coastline.
Due to the geographic complexity developed by faulting on the active tectonic margin, distinct rocks and soils can be juxtaposed within the same valley or range, giving surprising nuance and character to the wine.
Viticulture, while not geology, also plays a role in terroir: selecting grape varieties, cultivating the vines and harvesting the grapes.
Meet the experts
Interested in learning more? The latest addition to GeoCultura’s portfolio, California tour: the fabulous wines and geology of the coast, focuses on the interplay between the geology and the grapes in the greater Santa Barbara area. We tour a facility that prepares students for a career in wine (the Wine and Viticulture Center at the California Polytechnic State University), hear from an expert on terroir (Maia Daves, a soil scientist) and learn about the history of wine in Central California from Libbie Agran, the founder of the Wine History Project of San Luis Obispo. And, of course, visit a vineyard or three for tastings.
Our tour of California pays attention to glamour, culture and nature as well, with visits to Hearst Castle and La Purísima Mission and stops for geology, elephant seals, butterflies and botanic gardens.
Geologist Rick Behl, our California tour leader, is a near-lifetime resident of central California. He loves sharing his familiarity with the coast. And he is good at it, as evidenced by his recently being named Distinguished Educator for North America (AAPG, 2025)!
Come experience the California vibe with GeoCultura!