小气候，正如加利福尼亚索诺玛山的酿酒师Erica Stancliff所言，它们就像葡萄栽培区(AVA)中的亚AVAs。Stancliff在Trombetta Family Wines和Pfendler Vineyards工作，同时也是Petaluma Gap Winegrowers Alliance的一员，她将小气候定义为“与周围地区具有独特气候差异的一小部分地区”。这可能仅影响几英亩，也可能跨越数平方英里。影响小气候的环境因素包括接近水体的距离、土壤类型、地理特征、高海拔和低海拔以及温度和湿度，即使在同一个葡萄园内，这些特征也会有所不同。“这是酿酒师关于成熟度收获决定的重要考虑因素，而且这也是使一些较小规模的酿酒区和葡萄园如此独特的原因，”Stancliff说。
Matt Dis, a winemaker in Santa Barbara, California, has a profound understanding of how small climate differences impact his AVA's various regions. Just like in Sonoma County, Dis says the biggest determining factor is proximity to the ocean. Nearby vineyards feel the cold ocean air and fog. In these two AVAs, the series of hills, valleys, and plateaus make microclimates even more nuanced; all of which determine whether vineyards are exposed to marine influence or not.
For example, fog settles in valleys creating cool microclimates. Vineyards above the fog line get more sunlight exposure during the day with higher temperatures but experience more extreme diurnal temperature fluctuations due to elevation.
These details decide where certain varieties grow best. "Sta Rita Hills gets what we like to call 'cool-cold sun,'” Dis said. “It's very suitable for growing Pinot Noir, Chardonnay and Syrah.” Ballard Canyon [AVA]... [has] warm days and colder nights with limestone soils mixed with sand and clay; Syrah and Bordeaux varieties grow best there.”
Moving east towards Happy Canyon grapevines face even more extreme diurnal changes that help maintain acidity for widely planted Bordeaux varieties.
"I haven't even considered Los Alamos," Dis added about many sub-AVAs within broader Santa Barbara County AVA each having its unique environmental conditions.
Stancliff collaborates with several Sonoma County vineyards where Black Burgundy is one of the most widely planted varieties. Grapes are a case study on how to break down wider AVAs into specific environmental conditions.
"In some areas such as Russian River Valley," she said, "Black Burgundy ripens slightly faster than surrounding coastal areas resulting in different flavor profiles and tannin maturity." In Petaluma Gap due to long growing seasons you'll see mature tannins develop alongside fresh acidity deep color & ripe fruit flavors matching up."
Wind also plays an extremely important role in Petaluma Gap AVA named after mountain ridges' crevices gathering cool sea breezes inland "[it] defines our microclimate," Stancliff said; "grapevines react by forming thicker skins on grapes." Thicker skins will produce more color singletons & flavor intensity in so produced wines.
"For everything we do at cellar level it's important remember wine is defined by thousands related moments - wind sunshine root depth naturally human intervention" Dis said.
"Soil terroir driven by tens thousands such moments."
The subtle variations between these environments result in distinct wines that reflect their individual climates while sharing common regional characteristics – an ongoing exploration into defining place through nature’s palette
