The Paso Robles American Viticultural Area (AVA) was established in 1983 and at that time there were 556,765 total acres with a little over 5,000 under vine. In 1996, the AVA expanded by 52,600 acres and then again by 2,635 acres in 2008. In 2007, a petition was sent to the federal government to establish 11 districts within the Paso Robles AVA. In the same year, a conjunctive labeling law (AB 87) was passed, which preserves the brand awareness of the Paso Robles AVA by ensuring that “Paso Robles” will always be seen in conjunction with the districts on wine labels. These 11 districts within the Paso Robles AVA were finally approved in 2014.

The Paso Robles Wine Country Alliance will be focusing on all 11 AVAs in this blog through 2020, in alpha order.

The Adelaida District, which is the most northwestern of the 11 Paso Robles districts, approximately 53,100 acres, is well defined by its mountainous topography. Nestled within the southern end of the Santa Lucia Mountain Range, many slopes are covered with coastal and live oak woodland decorated by Lace Lichen. Lace Lichen? It’s what looks like Spanish Moss, but isn’t, and happens to be the State of California’s official State Lichen. Beyond the novelty, its existence suggests two things: a clean air environment because of its sensitivity to sulfur dioxide, as well as a damp setting, which is fitting since the Adelaida District is one of the wettest of the Paso Robles districts due to the orographic influence as storms travel from the Pacific Ocean, east.

One of the most important characteristics of an AVA is geology and the Adelaida District likes to show off its geology to anybody willing to look. Traveling along its curvy roads, road cuts reveal white chalky rock, evidence of ancient marine sediment from the Mesozoic time. Limestone can also be found along the wine trail, often used in stacked stone walls surrounding vineyards and wineries. This yellowed sedimentary rock is obvious from its tell-tale streaks of crystallized calcite and dense mass. While not widespread in the Paso Robles AVA, it has a history in the Adelaida area that was originally discovered for mining.

In the last half of the 19^th century, California had been going through some big changes. Except for a few port cities, most of the newly founded state was a dry, inhospitable wilderness. With the gold rush in full swing, a few entrepreneurs managed to find success, not in gold but in other valuable commodities: Quicksilver ore, Charcoal, Mercury, Cattle, and various Agriculture. Ranchers, miners, and farmers alike carved out pieces of the Santa Lucia Mountains as best they could, fighting off wild animals, extreme weather, and difficult terrain to make a living.

In 1973, famed winemaker and viticulturist Andre Tchelistcheff came to Paso Robles at the request of Doctor Stanley Hoffman to consult at the Hoffman Mountain Ranch (HMR). His guidance helped the Hoffman’s achieve wines of merit in various international competitions. Mr. Tchelistcheff said of the HMR project: “Love, devotion, and self-sacrifice are very rare in this day, but they are needed to make great wines and the Hoffman boys have these qualities”. He also called HMR Vineyards “a jewel of ecological elements”, which today remains true as the HMR vineyard is still producing high-quality fruit. 

What at times seems like a legend in Paso Robles is rainfall. On the average, the Adelaida District receives around 30 inches of rain in a year cycle, which is approximately 20 more inches than some of the dryer parts of the Paso Robles AVA. On exceptionally wet years, vineyards have measured up to 45 inches of precipitation, and somewhere around nine inches in dry years. Luckily, the calcareous soil has both water retentive capabilities and good drainage. This duality comes as a result of much of the calcareous rock being porous, like a sponge, and yet because it fractures easily, it allows water to travel deeper into the bedrock. The sponge-like qualities prove to be important as vines grow deep seeking out moisture during the warm summers. 

There is a modest maritime influence from the Pacific Ocean as the warm air of the Paso Robles area rises, mixing with the cool moist air on the coast, creating fog that will roll in and out of Estero Bay to the west. A vacuum effect is created that brings cooling winds into the Paso Robles AVA. Further south of the Adelaida District, the Templeton Gap sees these winds standing up flags, but back up in the north, these winds are less dynamic but with equal cooling power. The diurnal variance of the Adelaida District can vary between morning lows of 50 degrees Fahrenheit to afternoon highs of 95 degrees Fahrenheit in the height of summer.

There is a common thread with many of these growing conditions shared across the Paso Robles AVA, but to different degrees or extremes. The Adelaida District assuredly has the highest elevation at 2,200 feet but shares its geology, diurnal temperature swings, and other attributes with its neighboring AVAs. What is certain is that growers in the Adelaida District, even prior to it officially becoming an AVA, take advantage of these circumstances to grow the best fruit possible, leading to some exceptional wines. 

Special thanks to Joe Kowalski for his historic input into this article. Joe is the author of Nacimiento, Birth of the Dragon, a written and visual documentation about the history of Lake Nacimiento and the surrounding communities.

Photo Credit: Thank you Adelaida Vineyards & Winery, DAOU Vineyards & Winery,  Halter Ranch Vineyard, Tablas Creek Vineyard, and Acacia Productions.