The puzzle map that makes up the Sonoma County American Viticulture Area got a new piece this month. After years of petitioning, Moon Mountain District – Sonoma County was officially added to the map. With rocky hillsides and cooling coastal breezes, proponents say it’s significantly different than the Sonoma Valley appellation, and thus deserving of its own AVA.
“It’s all about the fact that it’s a mountain,” said Christian Borcher, who has his own private 7-acre vineyard on Trinity Road, and led the effort to establish the Moon Mountain AVA. “It made sense to carve it off from Sonoma Valley because it’s not a valley. It’s a different climate up on the mountain.”
Made up of 17,663 acres total – including 11 wineries and 40 vineyards representing 1,500 acres of wine grapes, Moon Mountain District – Sonoma County is a long, narrow sliver on the western slope of the Maycamas Mountains that ranges in elevation from 400-feet to 2,200-feet at its highest point. Until recently, it was an unnamed peak that was colloquially known as Moon Mountain because it’s accessed by Moon Mountain Drive. In 2007, residents successfully petitioned the U.S. Geological Survey’s Board on Geographic Names to officially designate the peak Moon Mountain, opening the door for the AVA process.
“There had been two or three attempts to get this done in the past 25 years before we were successful,” Borcher said.
He explained that the vintners on Moon Mountain worked collectively for more than a year to secure their own designation on the AVA map, with petitions to the Alcohol and Tobacco Tax Trade Bureau. The group had a shared financial motive. Thanks to its steep, rocky terrain, the cost to farm the mountainous region is significantly higher than in other areas, both in planting the vines and harvesting the fruit.
“In a lot of ways it came down to the cost of farming,” Borcher admitted, explaining that the only way to recoup the added expenses was through “selling luxury bottles at a higher price.” Being a part of a smaller, more exclusive AVA will allow vintners to command a higher price per bottle.
But, Borcher added, the wines produced on Moon Mountain have their own signature style that also makes them deserving of a unique AVA. Unlike the Valley floor, where moisture can more easily collect in the soil, it is harder to keep water and nutrients in the vines on Moon Mountain. Additionally, farmers have to find a balance between the hot air that rises along the mountain and increased sun exposure with the cold bursts of fog and cool winds that whip off San Pablo Bay.
“The grape vines are always stressed out up here,” Borcher said.
These environmental stressors lead to smaller fruit with a higher skin-to-juice ratio. Skins play a pivotal role in how a wine tastes.
“A lot of the flavor you want in a wine comes from the skins of the grape,” Borcher said. “Moon Mountain tends to produce more intensely flavored wines.”
Too hot for pinots, Bourdeux and Rhône varietals grow well on Moon Mountain, such as cabernets, petit verdot, malbecs, mourvedres and syrahs. The historic Monte Rosso vineyard – first planted by famed vintner Louis Martini and now owned by Gallo Family Wines, is nestled into the new AVA. Other Moon Mountain wine producers include Kamen Estate, Coturri Vineyards, Petroni Vineyards, B. Wise Vineyards, Hanzell Vineyards and Liquid Sky Vineyards, among others. The new AVA marks Sonoma County’s 16th appellation, and the fourth in Sonoma Valley.