Today we are sipping a bit closer to home. In our glass is a red blend from the volcanic soils of High Valley AVA in Lake County, Northern California. We will take a look at the region, the winery and the sustainability of cork closures. We received this wine as a tasting sample.
Lake County’s AVAs
Lake County is situated around Clear Lake, the largest lake within California’s boundaries, according to Wikipedia. Clear Lake sits north of Napa County in the Coast Ranges where the Mayacamas Mountains and the Vaca Mountains come together. (1)
The Lake County wine region has quite a lot going for it. The region boasts the cleanest air in California and high elevations (between 1,370 and 3,000 feet above sea level), resulting in low humidity and excellent UV exposure. These factors combine to reduce disease pressure and encourage thicker grape skins, which can result in higher tannins and increased phenolic content. The growing season is relatively short with colder winters. Add in a significant diurnal shift in temperature during the growing season and complex, volcanic soils and you’ve got the potential for some exciting wines. The Lake County wine region is home to nine AVAs located around Clear Lake. See this interactive map for AVA details in Lake County and the US.
High Valley AVA
Brassfield Estate Winery, established in 2000, is located in the High Valley AVA along Clear Lake’s eastern shore. High Valley has an east-west orientation (uncommon in California) and relatively high elevations: most vineyards are planted at between 1,500 and 2,400 feet above sea level, with a few as high as 3,000 feet.
According to Lake County Winegrape Commission three distinct growing areas have been identified in the High Valley AVA. Growing conditions are coolest on the valley floor where cooling breezes blow across Clear Lake. On the east side of the valley near Round Mountain, where the soils are bright red and well-drained, some vineyard sites are quite steep. Ridges along the west side of the valley are also volcanic with shallow sand, gravel, and tephra that hold little water.
Brassfield Estate Winery
In 1973 Jerry Brassfield purchased 1,520 acres, known as High Serenity Ranch near Clearlake Oaks. What began as a cattle ranch and getaway for the family eventually became Brassfield Estate Winery. Taking a cue from other growers in the valley, Brassfield began testing soil and identifying the best vineyard sites before planting the first vines in 2001.
Brassfield purchased the Round Mountain property in 2003 and established the Volcano Ridge Vineyard. The 80-acre vineyard planted adjacent to Round Mountain Volcano is the source of grapes for Eruption, the wine we are tasting today.
Growth has been continuous at Brassfield Estate Winery. Perspective Vineyard, a high-density Syrah and Viognier planting sitting at close to 3,000 feet, was established to make their Syrah Perspective wine. With the purchase of additional acreage the Ridgeline Vineyard was planted, nearly doubling the acres planted. In 2022 Brassfield purchased High Valley Ranch bringing the estate holdings to 4,747 acres. Only 10% of the total acreage is planted to vines leaving the vast majority wild.
Along the way winemaking facilities and tasting room have been built including an enormous cave system used to age Brassfield Estate wines. Both the winemaking facility and estate vineyards are certified sustainable by the California Sustainable Winegrowing Alliance. All wines are estate grown, made and bottled.
Let’s Taste
2022 Brassfield Estate Winery Eruption, High Valley AVA — dark ruby with generous aromas of ripe boysenberries, blackberries and alfalfa hay. Flavors are complex with ripe berries and plums, tobacco, leather and earth along with slate minerality. The body is medium. Tannins are gauzy and drying. 15% ABV. About $20
I couldn’t find the blend or the aging details of this wine, but as mentioned earlier it is sourced from Volcano Ridge Vineyard. According to the winery website:
Originally planted in 2003 and 2004, Volcano Ridge (created by hundreds of eruptions from the nearby Round Mountain Volcano) totals 85 acres devoted to all red varietals, with numerous clones of each (primarily 110R rootstock). At 1900 – 2200 ft. elevation, the volcanic sands and tephra (small, fused sand pebbles) of the Konocti Series make for excellent drainage. Vines struggle in these soils, and the intensity of that struggle is reflected in the layers of complexity and structure, in the concentrated fruit, and in the final expression of Volcano Ridge wines.
Cork Sustainability
According to the Natural Cork Council, a non-profit established to educate the public and the wine industry about the importance of sustainable practices, cork closures are a sustainable choice. Long the closure of choice for wine bottles, natural corks are a more sustainable choice than screw caps or glass. Not only does the production of natural corks have a lower carbon footprint, but Mediterranean cork forests act as a carbon sink for 14 million tons of CO2.
The demand for cork helps preserve cork forests and because cork trees are not cut down to harvest the cork, it is a renewable resource. Only the outer bark of cork oak trees is harvested every eight to 12 years and they can live for 200 years supporting not only the workers who harvest the cork, but biodiversity within the forests. For more information about cork forests, production and uses see the very detailed APCOR (Portuguese Cork Association) website.
Speaking of natural cork, the Brassfield Eruption is closed with an agglomerated cork. Agglomerated corks can be made in several ways, but, essentially, their manufacture uses natural cork particles created in the manufacture of natural stoppers. The link above describes their manufacture. I couldn’t pass up the opportunity to photograph the cork, laden with sparkling “wine diamonds!”
It is possible to recycle natural corks after you pull that cork, though not for re-use in a wine bottle (thank goodness). ReCORK, North America’s largest cork recycling program according to their website, reuses cork in a variety of ways. There is a collection site locator on the ReCORK website. We are able to recycle natural corks, along with wine bottles, in our residential recycling bin.
Thanks to Colangelo & Partners for organizing our tasting.
Cheers!
(1) Nickles, J. (2025). 2026 Certified Specialist of Wine Study Guide. Society of Wine Educators.
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