Port wine be labelled as "port" or "Porto". In the United States, wines labelled "port" may come from anywhere in the world, while the names "Oporto", "Porto", and "Vinho do Porto" have been recognized as foreign, non-generic names for port wines originating in Portugal. Port is produced from grapes grown and processed in the demarcated Douro region. The wine produced is then fortified by the addition of a neutral grape spirit known as aguardente in order to stop the fermentation, leaving residual sugar in the wine, and to boost the alcohol content. The fortification spirit is sometimes referred to as brandy but
Wine Country (California) Valley, and Russian River Valley in Sonoma County. Wine grapes are also grown at higher elevations, such as Atlas Peak and Mount Veeder AVAs. Cities and towns associated with the Wine Country include Santa Rosa, Healdsburg, Sonoma, Kenwood, Petaluma, Sebastopol, Guerneville, Windsor, Geyserville, and Cloverdale in Sonoma County; Napa, Yountville, Rutherford, St. Helena and Calistoga in Napa County; and Hopland and Ukiah in Mendocino County. Lake County is an increasingly important part of the area, surpassing Mendocino County in 2014 in price paid per ton of grapes in the North Coast premium market. Wine Country is generally regarded as the