Calistoga is an AVA covering an area of the valley floor surrounding Calistoga town in the northern Napa Valley. It is one of the warmest parts of the valley and is most notable for its red wines made from Cabernet Sauvignon and Zinfandel.
Calistoga's first vines were planted in 1862, several years before Henry Walker Crabb put down roots in his To Kalon vineyard at nearby Oakville. Documentation from the 1880s shows Calistoga was treated as an entirely distinct region from Napa at that time. This is not difficult to understand when one considers how the local climate and topography separate Calistoga from St Helena and the rest of the valley.
The Calistoga appellation's key advocate was Bo Barret of Chateau Montelena (arguably the AVA's most prestigious winery), who began petitioning for separate AVA status in 2003. No doubt Barret's high profile and reputation (he created the Chateau Montelena Chardonnay which triumphed at the Paris Judgment of 1976) lent weight to the case, and helped deflect the AVA's many critics. Approval finally came from the US Alcohol and Tobacco Tax and Trade Bureau in 2009, and took effect as of the 2010 vintage.
When the appellation was proposed, the two main opponents were Calistoga Cellars and Calistoga Estate, the local wineries which bear the AVA's name. Their resistance centered around the fact that US wine law would force them to make all of their wines using at least 85 percent of grapes from the new AVA. Prior to 2003, neither of these wineries did so, and would otherwise be forced to change their brand names. The final ruling on this matter was that the two wineries would have to comply with the 85 percent rule by the 2013 vintage.
Climate data clearly shows that the summer months in Calistoga are significantly hotter than further south in the valley, demonstrating perfectly that being further from the equator does not always equate to cooler average temperatures. The fact that the Napa Valley becomes progressively cooler as it follows along the Napa river southwards is largely due to the cooling influences brought by the bodies of water which lie to the south: San Francisco Bay, San Pablo Bay, Suisun/Grizzly Bay and the Sacramento-San Joaquin River Delta. Thus many Calistoga vineyards are noticeably warmer than those in, say, Carneros, which lies just a few miles from San Pablo Bay and enjoys all the refreshing coolness of the local fog and breezes.
The laws of convection mean cool, moisture-laden air (including the famous San Francisco fog) moves up the valley as the land warms during the day, and back down again in the evening. This cools the vineyards down and helps them to retain the acidity vital for quality winemaking. However, the breezes and fog gradually disperse with each increase in altitude and distance from the ocean, meaning Calistoga vineyards receive almost no benefit from this climatic phenomenon. They rely instead on what coolness can be drawn from the Napa river which bisects the AVA, and from their increased elevation; Calistoga sits a small but significant 400ft (120m) higher than Napa.
Red wines far outweigh whites here. Cabernet Sauvignon and Zinfandel are the undisputed kings of the Calistoga vineyard, accompanied by Cabernet Franc and Syrah. The few white wines made here are based on Sauvignon Blanc and, of course, Chardonnay.